Of Pregnancy, Flu & Autism

 

Photo Credit – CDC

 

# 6711

 

We’ve known for a long time that influenza during pregnancy can endanger the mother, and unborn child’s life. Furthermore, it appears that pregnant women are more susceptible to influenza than are non-pregnant women.

 

Why is not exactly known, although it is theorized that the normal protections of a woman's immune system are temporarily altered to allow her to carry what is essentially a foreign body - a fetus - without rejection.

 

During the 2009 H1N1 pandemic pregnant women were six times more likely to be hospitalized than non-pregnant women (see Pregnancy & Flu: A Bad Combination). 

 

And in 2011, in BMJ: Perinatal Outcomes After Maternal 2009/H1N1 Infection we saw a study where pregnant women who were admitted to the hospital with an  H1N1 infection experienced a 3 to 4 times higher rate of preterm birth, 4 to 5 times greater risk of stillbirth, and a 4 to 6 times higher rate of neonatal death.

 

Over the past decade we’ve also seen a handful of studies tentatively linking prenatal exposure to influenza (or an influenza-like-illness) with a variety of child and adolescent development disorders. 

 

A few examples include:

 

• In a 2004 study (Serologic evidence of prenatal influenza in the etiology of schizophrenia  Brown et al.) found a 7-fold increase in the risk of developing schizophrenia when exposed to influenza during the first trimester. No increased risk was found for exposure during the second and third trimester.

 

• Another study from 2008 (Structural brain alterations in schizophrenia following fetal exposure to the inflammatory cytokine interleukin-8  Ellman et al.) suggested that it was prenatal exposure to a type of protein - (proinflammatory cytokines, specifically interleukin-8) – produced by the body during viral infections, that can lead (in rare cases) to brain abnormalities.

 

• And earlier this year, research by a team at UC Davis found that fever (from any cause) during pregnancy more than doubled the odds of having a child with autism or developmental delays (see  Is Maternal Influenza or Fever During Pregnancy Associated with Autism or Developmental Delays? Results from the CHARGE (CHildhood Autism Risks from Genetics and Environment) Study  Zerbo et al.)
• • Flu, specifically, during pregnancy was not associated with greater developmental risks only fever by `any cause’.
  • Children of mothers who took antipyretics for fever did not show any increase in developmental disorders.

 

These studies are admittedly small and less than conclusive.

 

And while they suggest an increase in relative risk over pregnancies without fever or viral infection – in terms of absolute risk – the odds that a mother’s fever or viral infection during pregnancy would result in a developmentally challenged child remains low.

 

Today, we’ve a new study appearing in the journal Pediatrics that adds, incrementally, to earlier suspicions regarding prenatal exposure to influenza and the risks of developmental disorders.

 

Researchers followed up on more than 96,000 Danish children born between 1997 and 2003. They compiled a (self reported) history of the mother’s pregnancy (including infections, fevers, and antibiotic use), and compared that to diagnoses of ASD and infantile autism among the children.

 

Autism After Infection, Febrile Episodes, and Antibiotic Use During Pregnancy: An Exploratory Study

Hjördis Ósk Atladóttir, MD, PhD, Tine Brink Henriksen, MD, PhD, Diana E. Schendel, PhD, and Erik T. Parner, PhD^d

RESULTS: Overall, we found little evidence that various types of mild common infectious diseases or febrile episodes during pregnancy were associated with ASD/infantile autism. However, our data suggest that maternal influenza infection was associated with a twofold increased risk of infantile autism, prolonged episodes of fever caused a threefold increased risk of infantile autism, and use of various antibiotics during pregnancy were potential risk factors for ASD/infantile autism.

 

The two major findings were:

 

• A twofold increase in autism among children with prenatal influenza exposure
• A threefold increase in autism among children with prolonged prenatal fever exposure

 

It should be noted that these are relative risk increases, and once again, the absolute risk of having an autistic or developmentally challenged child after experiencing an influenza infection or fever during pregnancy is still quite low.

 

Nor does this study point to influenza (or fever) during pregnancy as being a major cause of autism.  For now, this study only suggests that these could be two of many possible causes for the disorder.

 

And this caveat: This just one study, based on a limited cohort of subjects, that relied heavily on (potentially unreliable) self-reporting of illness/fever during pregnancy.

 

Meaning that we need to approach these findings cautiously.

 

Maggie Fox of NBC News has more on this story.

 

Flu, fever linked with autism in pregnancy study

By Maggie Fox, NBC News

Doctors trying to find some of the causes of autism put another piece into the puzzle on Monday: They found women who had flu while they were pregnant were twice as likely to have a child later diagnosed with autism. Those who had a fever lasting a week or longer -- perhaps caused by flu or maybe by something else -- were three times as likely to have an autistic child.

(Continue . . .)

 

Even without this latest study, the preponderance of evidence continues to show that pregnant women – and their unborn children – are at greater risk from influenza than most people appreciate.

 

Which is why the the CDC and other public health entities continue to stress the importance of seasonal flu vaccination for pregnant women.

 

In October of 2011, in IDSA: Flu Vaccines In Pregnancy, we saw several studies presented at the 49th Annual Meeting of the Infectious Diseases Society of America (IDSA) reaffirming the benefits and safety of maternal vaccination.

 

The CDC has synopsized these studies in:

 

Pregnancy and Influenza Vaccine Safety

 

Vaccines are drugs, and there is no such thing as a 100% safe and 100% effective drug. Even taking over-the-counter medicines entail some risks.

 

But the safety profile of flu vaccines is excellent, and serious side effects are exceedingly rare.

 

The overwhelming evidence shows that the real risk comes from the virus, not from the shot.

»» Read More

BMJ: H1N1 Vaccination & Fetal Death Rates

Photo Credit – CDC

 

# 6311

 

 

One of the persistent myths on the internet is that the 2009 H1N1 vaccine was responsible for `thousands’ of miscarriages. One need only Google `Vaccine + Miscarriage’ to see some of the propaganda out there.

 

It is a sad but true statistic that in the United States about 1 million women experience a miscarriage every year. That works out to be about 2,500  miscarriages each day.

 

And if we could vaccinate all of the pregnant women in the country today, tomorrow 2500 would still miscarry.

 

And most would probably blame the vaccine.

 

There is no such thing as a 100% benign drug, and so the possibility exists that a vaccine could produce serious adverse side effects. Which is why monitoring systems like VAERS are utilized to try to detect any spike in adverse effects from vaccines.

 

Over the past 3 years we’ve seen very encouraging reports on the safety of the 2009 pandemic vaccine. Last October in Lancet: Guillain-Barré Syndrome & H1N1 Vaccine In Children) we learned:

 

Surveillance and reporting systems have not found any unusual pattern of deaths in the United States attributable to the pandemic vaccine, and the oft predicted spike in Guillain-Barré syndrome (GBS) never occurred (see CIDRAP VAERS study finds H1N1 vaccine safety similar to seasonal vaccines').

In fact, the VAERS report cited above found 0 deaths they could link to the pandemic Vaccine. Meanwhile, during the same period the CDC estimated that at least 12,000 (mostly younger) Americans died from the flu.

 

 

And today, in the BMJ, we’ve another study of a large cohort of pregnant women in Demark that reassuringly finds no increase in miscarriage among those who received the 2009 H1N1 vaccine.

 

 

Vaccination against pandemic A/H1N1 2009 influenza in pregnancy and risk of fetal death: cohort study in Denmark

Published 2 May 2012  BMJ 2012;344:e2794

Abstract (excerpt)

Results The cohort comprised 54 585 pregnancies; 7062 (12.9%) women were vaccinated against pandemic A/H1N1 2009 influenza during pregnancy. Overall, 1818 fetal deaths occurred (1678 spontaneous abortions and 140 stillbirths). Exposure to the H1N1 vaccine was not associated with an increased risk of fetal death (adjusted hazard ratio 0.79, 95% confidence interval 0.53 to 1.16), or the secondary outcomes of spontaneous abortion (1.11, 0.71 to 1.73) and stillbirth (0.44, 0.20 to 0.94). Estimates for fetal death were similar in pregnant women with (0.82, 0.44 to 1.53) and without comorbidities (0.77, 0.47 to 1.25).

 

Conclusion This large cohort study found no evidence of an increased risk of fetal death associated with exposure to an adjuvanted pandemic A/H1N1 2009 influenza vaccine during pregnancy.

 

 

This latest study closely matches the findings of other researchers, such as we saw in  Hong Kong: No Increase In Fetal Death Among Vaccine Recipients.

 

Ironically, while some seek to demonize the flu vaccine as causing fetal deaths, in October of last year in UK: Pregnancy And Swine Flu a study conducted at Oxford University by the National Perinatal Epidemiology unit found a strong link between infection with the 2009 `swine’ flu and an increased number of stillbirths.

 

Fetal deaths among women infected with the H1N1 virus were 5 times higher than normal.

 

Very early into the 2009 H1N1 outbreak – even before the declaration of a pandemic by the World Health Organization – it became apparent that pregnant women were making up a disproportionate number of ICU admissions for influenza, and deaths.

 

Which is a pattern we’ve seen in pandemic outbreaks in the past (see Pregnancy & Flu: A Bad Combination).

 

 

The truth is, the flu virus is a far greater danger to pregnant women and their unborn child than the vaccine.

 

While the CDC and other public health entities continue to stress the importance of seasonal flu vaccination for pregnant women, there remains reluctance among some pregnant women to get the shot.

 

Vaccines are drugs, and there is no such thing as a 100% safe and 100% effective drug. Even taking over-the-counter medicines entail some risks.

 

But the evidence continues to show that flu vaccines are among the safest drugs available, and that most years they can provide decent protection against a serious and potentially deadly illness.

 

For more reassuring research on the safety profile of modern flu vaccines, you may wish to revisit the following blogs:

 

Harvard Study Reaffirms Safety Of Flu Vaccine

MJA: Safety Of Flu Shot In Young Children

NEJM: Study On China’s H1N1 Vaccine Safety

Lancet: Immunogenicity and safety Of Adjuvanted Flu Vaccines

»» Read More

IDSA: Flu Vaccines In Pregnancy

 

 

 

Photo Credit – CDC

# 5920

 

 

Last week, in UK: Pregnancy And Swine Flu, we saw a study conducted at Oxford University by the National Perinatal Epidemiology unit that found a strong link between infection with the 2009 `swine’ flu and an increased number of stillbirths.

 

Fetal deaths among women infected with the H1N1 virus were 5 times higher than normal.

 

Very early into the 2009 H1N1 outbreak – even before the declaration of a pandemic by the World Health Organization – it became apparent that pregnant women were making up a disproportionate number of ICU admissions for influenza, and deaths.

 

Which is a pattern we’ve seen in pandemic outbreaks in the past (see Pregnancy & Flu: A Bad Combination).

 

While the CDC and other public health entities continue to stress the importance of seasonal flu vaccination for pregnant women, there remains some reluctance among pregnant women to get the shot.

 

Last week, several studies were presented at the 49th Annual Meeting of the Infectious Diseases Society of America (IDSA) reaffirming the benefits and safety of maternal vaccination.

 

The CDC has synopsized these studies and included a link to the IDSA press release.

 

Pregnancy and Influenza Vaccine Safety

Research shows:

Influenza vaccination during pregnancy protects newborns from getting influenza.

Pregnant women who get influenza vaccine pass their immunity to their babies in the form of flu antibodies. This protection lasts for several months after birth. Influenza protection was seen in newborns up to four months old. Babies born to women who were not vaccinated during pregnancy showed no antibody protection.

Influenza vaccination does not cause miscarriage.

Research shows no association between flu vaccination during pregnancy and miscarriage. This largest study conducted during the first trimester showed pregnant women who got the flu vaccine were no more likely to miscarry than those who did not get the flu vaccine.

More pregnant women are getting vaccinated against influenza.

The number of pregnant women receiving influenza vaccine has increased dramatically in the last couple of years in large part due to a national effort to vaccinate against the 2009 H1N1 pandemic influenza during the 2009-10 influenza season. Prior to 2009, less than 15 percent of pregnant women got vaccinated. In the past two influenza seasons, over half of pregnant women were vaccinated.

For more information on these studies, read the IDSA press release.

 

 

 

Vaccines are drugs, and there is no such thing as a 100% safe and 100% effective drug. Even taking over-the-counter medicines entail some risks.

 

But the safety profile of flu vaccines is excellent, and serious side effects are exceedingly rare.

 

The real risk comes from the virus, not from the shot.

While studies like the ones above are unlikely to dissuade most anti-vaccination activists, hopefully they will provide some reassurance to women who are considering the vaccine, but are still on the fence.

»» Read More

UK: Pregnancy And Swine Flu

 

 

# 5909

 

 

There’s a report making a splash in the UK media today showing a link between increases in stillbirths and maternal deaths and infection with the 2009 H1N1 `swine’ flu.

 

This is a pattern we’ve seen with earlier pandemic flu viruses, although the exact reason behind it remains a mystery.

 

First, the story from the BBC on research conducted by the National Perinatal Epidemiology Unit at Oxford University, then I’ll return with more.

 

 

19 October 2011 Last updated at 02:46 ET

Study finds link between swine flu and stillbirth

By Dominic Hughes

Babies born to mothers who contracted the swine flu virus faced a much greater risk of being stillborn, according to a new study.

 

Baby deaths among women infected with the 2009 strain of the virus were five times higher than normal.

 

There was also a greater risk of premature births when compared to mothers who had not caught the virus.

(Continue . . . )

 

 

Noticeably absent from this report (and others in the media) is a link to the study, but this story appears to be based on a BMJ  open access study I wrote about last June.

 

Perinatal outcomes after maternal 2009/H1N1 infection: national cohort study

Matthias Pierce, Jennifer J Kurinczuk, Patsy Spark,Peter Brocklehurst, Marian Knight

Results Perinatal mortality was higher in infants born to infected women (10 deaths among 256 infants; rate 39 (95% confidence interval 19 to 71) per 1000 total births) than in infants of uninfected women (9 deaths among 1233 infants; rate 7 (3 to 13) per 1000 total births) (P<0.001). This was principally explained by an increase in the rate of stillbirth (27 per 1000 total births v 6 per 1000 total births; P=0.001). Infants of infected women were also more likely to be born prematurely than were infants of comparison women (adjusted odds ratio 4.0, 95% confidence interval 2.7 to 5.9). Infected women who delivered preterm were more likely to be infected in their third trimester (P=0.046), to have been admitted to an intensive care unit (P<0.001), and to have a secondary pneumonia (P=0.001) than were those who delivered at term.

Conclusions This study suggests an increase in the risk of poor outcomes of pregnancy in women infected with 2009/H1N1, which reinforces the message from studies of maternal risk alone. The health of pregnant women is an important public health priority in future waves of this and other influenza pandemics.

 

 

Even before the novel H1N1 virus emerged in the spring of 2009, pregnancy was considered to be a significant risk factor during an influenza pandemic.

 

Researchers saw during the 1918 Spanish Flu that an abnormally high number of pregnant women died, and those that survived endured a very high miscarriage rate.

 

Even during the much milder 1957 Asian Flu, pregnant women reportedly suffered disproportionately higher mortality rates than non-pregnant women of the same age (cite Rasmussen SA, Jamieson DJ, Bresee JS. Pandemic influenza and pregnant women. Emerg Infect Dis)

 

And very early into the 2009 H1N1 outbreak – even before the declaration of a pandemic by the World Health Organization – it became apparent that pregnant women were making up a disproportionate number of ICU admissions for influenza.

 

Less than a month after the outbreak was detected, the CDC’s MMWR published case studies of three pregnant women who had contracted novel H1N1.

 

Throughout the summer, pregnancy and flu was a major topic by public health officials around the world, with the WHO issuing a Pandemic Briefing # 5: Influenza In Pregnant Women in late July of 2009.

 

Since then, we’ve seen a number of studies on the impact of the H1N1 virus on pregnant women, including BMJ Study: Pregnancy & Flu – published in the spring of 2010.  

 

Although it was widely reported (see Pregnancy & Flu: A Bad Combination) during 2009 that pregnant women were up to 6 times more likely to be hospitalized with influenza than were non-pregnant women, this study found the risks of influenza death among pregnant women to be actually higher.

 

And while pandemic flu seems to be worse for pregnant women than seasonal flu, both can produce serious complications.

 

Which is why the CDC, and most other public health agencies around the world, continue to encourage seasonal flu vaccination – particularly for at risk groups – which includes pregnant women.

 

Pregnant Women Need a Flu Shot!

Photo Credit – CDC

If you're pregnant, a flu shot is your best protection against serious illness from the flu. A flu shot can protect pregnant women, their unborn babies, and even their babies after birth.

(Continue . . .)

 

 

And as an added benefit, pregnant women who receive a flu shot can pass on important antibodies to their newborn infants – providing a degree of protection until they are old enough to receive the flu vaccine.

 

A study from Wake Forest Baptist Medical Center, that appeared earlier this year in American Journal of Obstetrics & Gynecology found that infants born to mothers who had received the flu vaccine during pregnancy were more than 45% less likely to be hospitalized with laboratory confirmed influenza.

 

For details on that research, you may wish to revisit Pssst! Immunity . . . Pass it On.

 

The bottom line is that influenza presents a serious health threat to both the mother, and to the child she carries, and that vaccination can help lower those risks.

»» Read More

Pssst! Immunity . . . Pass it On

 

 

 

# 5648

 

 

Two related stories today involving expectant mothers and vaccines that have been in the news over the past 48 hours.

 

Both suggest that one of the best ways to protect a newborn baby against influenza and pertussis is to vaccinate the mother before she gives birth.

 

In both cases, newborn infants are too young to receive vaccines during the first months out of the womb, but may acquire limited immunity from antibodies passed on from the mother.

 

First from the Advisory Committee On Immunization Practices (ACIP) meeting this week, a recommendation that pregnant women and other adults who will be in close contacts with a soon-to-be born infant receive the Pertussis vaccine.

 

CIDRAP has the details in last night’s news scan. 

 

 

ACIP recommends pertussis vaccine for pregnant women

To protect infants in a time of increasing pertussis cases, pregnant women as well as teens and other adults in close contact with newborns should receive pertussis (whooping cough) vaccine, an advisory group to the US Centers for Disease Control and Prevention (CDC) said yesterday. The panel, the Advisory Committee on Immunization Practices (ACIP), also recommended meningococcal vaccine for high-risk infants at 9 months, according to MSNBC. The CDC still needs to decide on the recommendations but often follows ACIP guidance.

(Continue . . . )

 

 

A second report, this time from Wake Forest Baptist Medical Center, revolves around a study that appears this month in American Journal of Obstetrics & Gynecology.

 

Impact of maternal immunization on influenza hospitalizations in infants

American Journal of Obstetrics and Gynecology, 2011; 204 (6): S141 DOI:

Katherine A. Poehling, Peter G. Szilagyi, Mary A. Staat, Beverly M. Snively, Daniel C. Payne, Carolyn B. Bridges, Susan Y. Chu, Laney S. Light, Mila M. Prill, Lyn Finelli, Marie R. Griffin, Kathryn M. Edwards.

 

It found that by analyzing data collected by CDC and the New Vaccine Surveillance Network between 2002 and 2009 (before the H1N1 pandemic), that infants born to mothers who had received the flu vaccine during pregnancy were more than 45% less likely to be hospitalized with laboratory confirmed influenza.

 

This isn’t the first time that studies have shown the benefits to the newborn child derived from maternal vaccination.  

 

Last October, in Study: Protecting Two With One Shot I blogged on Lisa Schnirring’s CIDRAP News story regarding a study that showed that babies born to mothers who received the flu vaccination experienced fewer infections and hospitalizations during their first six months than babies whose mothers did not.

 

And two years before that, we had a study conducted in Bangladesh (see CIDRAP’s Study: Flu shots in pregnant women benefit newborns) that offered pretty much the same conclusion.

 

Pregnant women (and their unborn child) are at particularly high risk from influenza due to changes in the mother’s immune system during pregnancy.  This is something I’ve written about often, mostly recently in BMJ: Perinatal Outcomes After Maternal 2009/H1N1 Infection.

 

Which is why the CDC encourages pregnant women to get the flu vaccine.

 

Pregnant Women Need a Flu Shot!

Photo Credit – CDC

If you're pregnant, a flu shot is your best protection against serious illness from the flu. A flu shot can protect pregnant women, their unborn babies, and even their babies after birth.

 

(Continue . . .)

 

 

 

While the importance of maternal flu vaccination has been stressed in pediatric journals in the past, this most recent study is geared for the OB/GYN audience, which will hopefully induce them to recommend flu shots to their patients.

 

For more on this, here is a link to the Press Release.

 

Wake Forest Baptist Medical Center

Influenza vaccination during pregnancy protects newborns

WINSTON-SALEM, N.C. – June 23, 2011 – Infants born to mothers who received the influenza (flu) vaccine while pregnant are nearly 50 percent less likely to be hospitalized for the flu than infants born to mothers who did not receive the vaccine while pregnant, according to a new collaborative study by researchers at Wake Forest Baptist Medical Center and colleagues.

(Continue . . . )

 

 

And for more on the re-emergence of Pertussis in this country, you may wish to read:

 

California Reports 9th Pertussis Fatality of 2010

California Whooping Cough (Pertussis) Update

California: Pertussis Epidemic

»» Read More

BMJ: Perinatal Outcomes After Maternal 2009/H1N1 Infection

 

 

# 5631

 

 

Even before the novel H1N1 virus emerged in the Spring of 2009, pregnancy was considered to be a significant risk factor during an influenza pandemic.  

 

Researchers knew that during the 1918 pandemic an abnormally high number of pregnant women died from the the Spanish Flu, and those that survived endured a very high miscarriage rate.

 

Even during the much milder 1957 Asian Flu, pregnant women reportedly suffered disproportionately higher mortality rates than non-pregnant women of the same age.

 

The following anecdotal reports come from a 2008 CDC EID Journal article:

 

Rasmussen SA, Jamieson DJ, Bresee JS. Pandemic influenza and pregnant women. Emerg Infect Dis [serial on the Internet].   

 

Among 1,350 reported cases of influenza among pregnant women during the pandemic of 1918, the proportion of deaths was reported to be 27% (5).

 

Similarly, among a small case series of 86 pregnant women hospitalized in Chicago for influenza in 1918, 45% died (6).

 

Among pregnancy-associated deaths in Minnesota during the 1957 pandemic, influenza was the leading cause of death, accounting for nearly 20% of deaths associated with pregnancy during the pandemic period; half of women of reproductive age who died were pregnant (7).

 

 

Pregnant women also appear to be more susceptible to influenza than non-pregnant women, although the exact reasons for this aren't well understood.

 

It is believed, however, that the normal protections of a woman's immune system are temporarily altered to allow her to carry what is essentially a foreign body- a fetus - without rejection.

 

And that alteration can place the mother (and child) at greater risk of infection from the influenza virus.

 

Which is why the CDC and many other public health agencies strongly encourage pregnant women to get vaccinated against both seasonal and pandemic influenza. 

 

 

Very early into the 2009 H1N1 outbreak – even before the declaration of a pandemic by the World Health Organization – it became apparent that pregnant women were making up a disproportionate number of ICU admissions for influenza.

 

On May 1st of 2009, a little more than a week after the first cases of novel H1N1 began to make headlines, the CDC published new guidelines for pregnant women in the Health Care or Education field that might come in direct contact with the Swine flu virus (See CDC Guidelines On Pregnancy And Pandemic Flu).

 

Two weeks after that the MMWR published case studies of three pregnant women who had contracted novel H1N1.

 

Throughout the summer, pregnancy and flu was a major topic by public health officials around the world, with the WHO issuing a Pandemic Briefing # 5: Influenza In Pregnant Women in late July of 2009.

 

Since then, we’ve seen a number of studies on the impact of the H1N1 virus on pregnant women, including BMJ Study: Pregnancy & Flu – published in the spring of 2010.  

 

 

Although it was widely reported (see Pregnancy & Flu: A Bad Combination) during 2009 that pregnant women were up to 6 times more likely to be hospitalized with influenza than were non-pregnant women, this study found the risks of influenza death among pregnant women to be actually higher.

 

 

Less well quantified has been the health impact on the unborn child when the mother was hospitalized with H1N1 influenza.

 

Today an open access research article in the BMJ that found that pregnant women who were admitted to the hospital with an  H1N1 infection experienced a 3 to 4 times higher rate of preterm birth, 4 to 5 times greater risk of stillbirth, and a 4 to 6 times higher rate of neonatal death.

 

 

 

Perinatal outcomes after maternal 2009/H1N1 infection: national cohort study

Matthias Pierce, Jennifer J Kurinczuk, Patsy Spark, Peter Brocklehurst, Marian Knight,

Accepted 13 April 2011

Abstract

Objectives To follow up a UK national cohort of women admitted to hospital with confirmed 2009/H1N1 influenza in pregnancy in order to obtain a complete picture of pregnancy outcomes and estimate the risks of adverse fetal and infant outcomes.

 

Participants 256 women admitted to hospital with confirmed 2009/H1N1 in pregnancy during the second wave of pandemic infection between September 2009 and January 2010; 1220 pregnant women for comparison.

 

Main outcome measures Rates of stillbirth, perinatal mortality, and neonatal mortality; odds ratios for infected versus comparison women.

 

Results Perinatal mortality was higher in infants born to infected women (10 deaths among 256 infants; rate 39 (95% confidence interval 19 to 71) per 1000 total births) than in infants of uninfected women (9 deaths among 1233 infants; rate 7 (3 to 13) per 1000 total births) (P<0.001).

This was principally explained by an increase in the rate of stillbirth (27 per 1000 total births v 6 per 1000 total births; P=0.001). Infants of infected women were also more likely to be born prematurely than were infants of comparison women (adjusted odds ratio 4.0, 95% confidence interval 2.7 to 5.9).

Infected women who delivered preterm were more likely to be infected in their third trimester (P=0.046), to have been admitted to an intensive care unit (P<0.001), and to have a secondary pneumonia (P=0.001) than were those who delivered at term.

Conclusions This study suggests an increase in the risk of poor outcomes of pregnancy in women infected with 2009/H1N1, which reinforces the message from studies of maternal risk alone. The health of pregnant women is an important public health priority in future waves of this and other influenza pandemics.

 

 

 

The bottom line is that influenza presents a serious health threat to the mother, and to the child she carries.  

 

While flu vaccines are very safe, and most years reasonably effective, many pregnant women avoid taking one out of fears they may experience a rare adverse reaction.

 

Today’s study highlights the fact that when you are dealing influenza and pregnancy, simply doing nothing represents a serious health risk of its own.

Risks that could be substantially reduced by vaccination.

»» Read More

HHS Webcast Today: Pregnant Women And Flu

 

 

# 4979

 

 

The HHS & CDC  will hold a special webcast later today – hosted on Flu.gov – with information directed towards pregnant women and the flu.

 

Today at 1:00 PM EDT on Flu.gov/Live

Pregnant Women and the Upcoming Flu Season

A Know What to Do About the Flu webcast focusing on the importance of vaccination for pregnant women, including a discussion on vaccine safety and benefits to newborn children. 

Guests:

• Howard Koh, M.D., M.P.H, Assistant Secretary for Health, HHS
• Denise Jamieson, M.D., Centers for Disease Control and Prevention
• Laura Riley, M.D., Member of the American Congress of Obstetricians and Gynecologists
• Siobhan Dolan, M.D., March of Dimes

»» Read More

NEJM: Enrolling Pregnant Women In Clinical Trials

 

 

# 4654

 

 

 

One of the more worrisome aspects going into pandemic of 2009 was the sheer lack of data on the safety of using antivirals on women who were pregnant.  

 

Public Health officials very early on had to weigh the benefits of their use during pregnancy against largely unknown risks.  Since that time, we’ve seen studies that have shown these drugs were used to good effect (see Study: Antivirals Saved Lives Of Pregnant Women)

 

In truth, the same situation exists for a wide range of drugs, since clinical trials often exclude pregnant women altogether.  

 

Clinicians are often put in the uncomfortable position of having to assume that these drugs will work in the same way, and at the same dosage, in pregnant patients.

 

Yet we know that pregnancy alters a woman’s metabolism, and down regulates her immune system.  Changes that conceivably could change the way some medications work in their bodies.

 

From the New England Journal of Medicine today we get a Perspective article on the need to enroll more women in clinical trials.  

 

This is a good article, and well worth reading.

 

Enrolling Pregnant Women in Research — Lessons from the H1N1 Influenza Pandemic

Sara F. Goldkind, M.D., Leyla Sahin, M.D., and Beverly Gallauresi, M.P.H.

»» Read More

Study: Pandemic H1N1 And Pregnancy

 

 

# 4593

 

 

Even before novel H1N1 emerged a little more than a year ago doctors and researchers were aware that novel influenza viruses often impacted pregnant women much harder than non-pregnant women.   

 

Although the concern at the time was a possible bird flu pandemic (and that concern has not diminished), back in December of 2008 I wrote a long essay on the subject entitled Pregnancy and Pandemic Influenza.

 

Much of what I wrote was based an a terrific study that appeared in the EID Journal in January of 2008 entitled Pandemic influenza and pregnant women by Rasmussen SA, Jamieson DJ, Bresee JS.

 

On May 1st of 2009, a little more than a week after the first cases of novel H1N1 began to make headlines, the CDC published new guidelines for pregnant women in the Health Care or Education field that might come in direct contact with the Swine flu virus (See CDC Guidelines On Pregnancy And Pandemic Flu).

 

Two weeks after that the MMWR published case studies of three pregnant women who had contracted novel H1N1. 

 

Throughout the summer, pregnancy and flu was a major topic by public health officials around the world. On October 1st, I summarized the impact of this new virus on pregnant women in Pregnancy & Flu: A Bad Combination. 

We are now in the process of getting many new studies and research articles based on what was learned over the past year.  Novel H1N1 will undoubtedly turn out to be the most studied influenza virus in human history.

 

Today, we get an investigation published in the Archives of Internal Medicine into 18 gravid (pregnant) admissions with H1N1, and their resultant complications.   

 

The authors report that pregnant patients admitted with H1N1 are “at risk for obstetrical complications including fetal distress, premature delivery, emergency cesarean delivery, and fetal death.”

The entire report is available online, and I’ve just reproduced excerpts from the abstract below.

 

Novel Influenza A(H1N1) Virus Among Gravid Admissions

Andrew C. Miller, MD; Farnaz Safi, MD; Sadia Hussain, BS; Ramanand A. Subramanian, PhD; Elamin M. Elamin, MD, MSc; Richard Sinert, DO

Arch Intern Med. 2010;170(10):868-873.

 
Background Pandemic novel influenza A(H1N1) is a substantial threat and cause of morbidity and mortality in the pregnant population.

 

Methods We conducted an observational analysis of 18 gravid patients with H1N1 in 2 academic medical centers. Cases were identified based on direct antigen testing (DAT) of nasopharyngeal swabs followed by real-time reverse-transcriptase polymerase chain reaction analysis (rRT-PCR) or viral culture.

<SNIP>

 

Results Eighteen pregnant patients were admitted with H1N1 during the study period. All patients were treated with oseltamivir phosphate beginning on the day of admission. Mean (SD) age was 27 (6.6) years (age range, 18-40 years); median length of hospital stay was 4 days.

 
Intensive care unit admission rate was 17% (n = 3).

<SNIP>

Seven patients delivered during hospitalization (39%), 6 prematurely and 4 via emergency cesarean delivery. There were 2 fetal deaths (11%). No maternal mortality was recorded.

 

Conclusions Admitted pregnant patients with H1N1 are at risk for obstetrical complications including fetal distress, premature delivery, emergency cesarean delivery, and fetal death. A high number of patients presented with gastrointestinal and abdominal complaints. Early antiviral treatment may improve maternal outcomes.

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Study: Antivirals Saved Lives Of Pregnant Women

 

UPDATED

# 4511

 

 

A study today, published in JAMA, points out the increased burden that pandemic H1N1 placed on pregnant women, and the apparent efficacy of early antiviral treatment in reducing mortality.

 

Mike Stobbe of the Associated Press has an overview, which is followed by the JAMA abstract, and a few comments of my own.

 

Study: Fast Tamiflu treatment saved many pregnant swine flu victims in US

MIKE STOBBE AP Medical Writer

ATLANTA (AP) — Quick treatment with flu medicine saved the lives of many pregnant women who were stricken by swine flu last year, according to the most complete analysis of deaths among expectant mothers.

 

The study by the Centers for Disease Control and Prevention counted 56 pregnant women who died from the new virus in 2009, confirming the dangers of the disease to this group.

 

Based primarily on U.S. figures from the first few months of the global epidemic, which began last April, CDC officials believe that though pregnant women account for just 1 percent of the population, they have at times accounted for as many as 5 percent of swine flu deaths.

(Continue. . . )

 

 

Excerpts from the JAMA Abstract follow:

 

Pandemic 2009 Influenza A(H1N1) Virus Illness Among Pregnant Women in the United States

Alicia M. Siston, PhD; Sonja A. Rasmussen, MD; Margaret A. Honein, PhD; Alicia M. Fry, MD; Katherine Seib, BS; William M. Callaghan, MD; Janice Louie, MD; Timothy J. Doyle, MPH; Molly Crockett, MPH; Ruth Lynfield, MD; Zack Moore, MD; Caleb Wiedeman, MPH; Madhu Anand, MPH; Laura Tabony, MPH; Carrie F. Nielsen, PhD; Kirsten Waller, MD; Shannon Page, BS; Jeannie M. Thompson, MPH; Catherine Avery, CFNP; Chasisity Brown Springs, MSPH; Timothy Jones, MD; Jennifer L. Williams, MSN; Kim Newsome, MPH; Lyn Finelli, DrPH; Denise J. Jamieson, MD; for the Pandemic H1N1 Influenza in Pregnancy Working Group

JAMA. 2010;303(15):1517-1525.

Context Early data on pandemic 2009 influenza A(H1N1) suggest pregnant women are at increased risk of hospitalization and death.

Objective To describe the severity of 2009 influenza A(H1N1) illness and the association with early antiviral treatment among pregnant women in the United States.

 

<SNIP>

 

Conclusions Pregnant women had a disproportionately high risk of mortality due to 2009 influenza A(H1N1). Among pregnant women with 2009 influenza A(H1N1) influenza reported to the CDC, early antiviral treatment appeared to be associated with fewer admissions to an ICU and fewer deaths.

 

 

You see a good deal of skepticism expressed online, and sometimes in the mainstream media, about the effectiveness and appropriateness of antiviral therapy for influenza.

 

Critics point out that the drug can have (rare) side effects and that it only reduces the duration of seasonal flu symptoms by an average of 1.3 days.    A modest but measureable benefit.

 

Where Tamiflu – and other antivirals – appear to make a bigger difference is in reducing symptoms in those who have pre-existing risk factors or conditions – including pregnancy – or those who are experiencing influenza complications.

 

And among H5N1 bird flu cases around the world, those that have survived (40%) were likely to have received early antiviral intervention.

 

Granted, most of the `evidence’ for the effectiveness of antivirals comes from observational studies, which some researchers find wanting (see BMJ: A Review Of Tamiflu’s Efficacy Against Seasonal Influenza).

 

Randomized controlled trials (RCTs) – while considered the `gold standard’ for drug research – are nearly impossible to conduct ethically since you’d have to withhold potentially life saving treatment from randomly selected test subjects. 

 

We would all like medicine to be based on treatments and drugs proved – beyond a shadow of a doubt – to be safe and effective . . . but sometimes we must accept a lower burden of proof -the preponderance of evidence - instead.  

 

And right now, the evidence continues to point to antivirals as being a valuable tool in the treatment of severe influenza.

 

 

UPDATE:

 

Lisa Schnirring of CIDRAP News has a very nice overview of this story entitled:

 

Early antivirals mean fewer ICU visits for pregnant pandemic flu patients

Lisa Schnirring Staff Writer

Apr 20, 2010 (CIDRAP News) – In the biggest and most detailed look yet at pandemic flu infections in pregnant women, researchers from the US Centers for Disease Control and Prevention (CDC) reported today that early antiviral treatment was linked to fewer intensive care unit (ICU) admissions and that severe illnesses and deaths are more likely to occur during the third trimester.

The CDC researchers, along with a Pandemic H1N1 Influenza in Pregnancy Working Group made up of health officials from several states, based their findings on reports of pregnant women who were sick with pandemic H1N1 infections through August plus more recent reports of women who were admitted to ICUs. The findings appear in the Apr 21 issue of the Journal of the American Medical Association (JAMA).

(Continue . . . )

»» Read More

Study: Antivirals During Pregnancy

 

 

 

# 4480

 

 

Going into the pandemic of 2009 one of the earliest dilemmas facing health officials and doctors was what to advise pregnant women regarding the use of antiviral medications.  

 

The simple fact is, for most modern medicines, there is simply insufficient information available regarding their safety during pregnancy.   Clinical trials using pregnant women are seldom performed because of the potential danger to the fetus.

 

As such, the FDA classifies many medications as Category C (insufficient information available to assess their potential risk and benefit during pregnancy).   Animal studies are performed, of course, but they don’t always predict with accuracy a drug’s effects on humans.

 

Pregnancy, however, has long been recognized as a serious risk factor during a pandemic.

 

Researchers know that during the 1918 pandemic an abnormally high number of pregnant women died from the influenza, and those that survived endured a very high miscarriage rate.

 

Even during the much milder 1957 Asian Flu, pregnant women reportedly suffered disproportionately higher mortality rates than non-pregnant women of the same age.

 

The following anecdotal reports come from:

 

Rasmussen SA, Jamieson DJ, Bresee JS. Pandemic influenza and pregnant women. Emerg Infect Dis [serial on the Internet]. 2008 Jan [date cited].

Available from http://www.cdc.gov/EID/content/14/1/95.htm

 

 

Among 1,350 reported cases of influenza among pregnant women during the pandemic of 1918, the proportion of deaths was reported to be 27% (5).

 

Similarly, among a small case series of 86 pregnant women hospitalized in Chicago for influenza in 1918, 45% died (6).

 

Among pregnancy-associated deaths in Minnesota during the 1957 pandemic, influenza was the leading cause of death, accounting for nearly 20% of deaths associated with pregnancy during the pandemic period; half of women of reproductive age who died were pregnant (7).

 

Pregnant women also appear to be more susceptible to influenza than non-pregnant women, although the exact reasons for this aren't understood. 

 

It is believed, however, that the normal protections of a woman's immune system are temporarily altered to allow her to carry what is essentially a foreign body- a fetus - without rejection.

 

And that alteration can place the mother (and child) at greater risk of infection during a pandemic.

 

Early in the outbreak of 2009 it became obvious that pregnant women were, once again, being hospitalized by the H1N1 virus at rates several times greater than for non-pregnant women. 

 

Faced with a rising mortality rate among pregnant women, the decision was made by most public health officials to recommend antivirals, even without the benefit of better studies.

 

In July, a retrospective analysis of existing studies concluded that antivirals appeared safe in pregnancy, a study I covered in Canadian Medical Journal: Antivirals Safe for Pregnant And Nursing Mothers.

 

And by the end of July the World Health Organization was recommending the immediate use of antivirals for pregnant women infected with the virus (see WHO Recommending Immediate Antiviral Treatment For Pregnant Flu Victims).

 

Today, in April edition of the Journal Obstetrics & Gynecology, we get some more information that indicates that public health officials made the right call.  

 

While limited in scope, this retrospective study showed no increase in adverse outcomes among pregnant women who received antivirals.

 

Obstetrics & Gynecology:

April 2010 - Volume 115 - Issue 4 - pp 711-716

doi: 10.1097/AOG.0b013e3181d44752

Original Research

Maternal and Neonatal Outcomes After Antepartum Treatment of Influenza With Antiviral Medications

Greer, Laura G. MD; Sheffield, Jeanne S. MD; Rogers, Vanessa L. MD; Roberts, Scott W. MD, MS; McIntire, Donald D. PhD; Wendel, George D. Jr MD

 

 

The entire study is a pay-per-view (follow above link for the abstract), but Medscape Today has an overview with the highlights.  Follow the link to read it in its entirety.

 

Antepartum Antiviral Treatment of H1N1 Influenza Not Linked to Adverse Outcomes

 

Laurie Barclay, MD

 

April 8, 2010 — Antepartum antiviral treatment of H1N1 influenza is not linked to adverse maternal or neonatal outcomes, according to the results of a retrospective cohort study reported in the April issue of Obstetrics & Gynecology.

 

(Continue . . . )

»» Read More

BMJ Study: Pregnancy & Flu

 

 

 

# 4448

 

 

One of the stories we’ve been long following (even before the outbreak of novel H1N1) has been the relationship between influenza and pregnancy.   

 

Researchers know that during the 1918 pandemic an abnormally high number of pregnant women died from the influenza, and those that survived endured a very high miscarriage rate.

 

Even during the much milder 1957 Asian Flu, pregnant women reportedly suffered disproportionately higher mortality rates than non-pregnant women of the same age.

 

The following anecdotal reports come from:

 

Rasmussen SA, Jamieson DJ, Bresee JS. Pandemic influenza and pregnant women. Emerg Infect Dis [serial on the Internet]. 2008 Jan [date cited].

Available from http://www.cdc.gov/EID/content/14/1/95.htm

 

Among 1,350 reported cases of influenza among pregnant women during the pandemic of 1918, the proportion of deaths was reported to be 27% (5).

 

Similarly, among a small case series of 86 pregnant women hospitalized in Chicago for influenza in 1918, 45% died (6).

 

Among pregnancy-associated deaths in Minnesota during the 1957 pandemic, influenza was the leading cause of death, accounting for nearly 20% of deaths associated with pregnancy during the pandemic period; half of women of reproductive age who died were pregnant (7).

 

Pregnant women also appear to be more susceptible to influenza than non-pregnant women, although the exact reasons for this aren't understood.

 

It is believed, however, that the normal protections of a woman's immune system are temporarily altered to allow her to carry what is essentially a foreign body- a fetus - without rejection.

 

While the impact of the pandemic of 2009 has been (thankfully) less than that seen with the 1957 Asian Flu, pregnant women have been hit disproportionately hard by this virus.

 

Last summer, it was widely reported (see Pregnancy & Flu: A Bad Combination) that pregnant women were up to 6 times more likely to be hospitalized with influenza than were non-pregnant women. 

 

As more time passes since the emergence of the novel H1N1 virus, new and more complete studies are released.   Our knowledge is refined, supplemented, and hopefully improved.

 

Today we’ve a new study that appears in the BMJ, entitled:

 

Critical illness due to 2009 A/H1N1 influenza in pregnant and postpartum women: population based cohort study

BMJ 2010;340:c1279

Objective To describe the epidemiology of 2009 A/H1N1 influenza in critically ill pregnant women.

Conclusions Pregnancy is a risk factor for critical illness related to 2009 H1N1 influenza, which causes maternal and neonatal morbidity and mortality.

 

 

This study indicates that the risks of influenza death among pregnant women was actually higher than first estimated last summer. I’ve lifted a few excerpts from the DISCUSSION section of this research, but please, follow this link to read the article in its entirety.

 

 

DISCUSSION

Pregnancy is a risk factor for 2009 H1N1 related critical illness. Of the 64 pregnant and postpartum women who were admitted to an intensive care unit in Australia and New Zealand with confirmed 2009 H1N1 infection, the risk of critical illness was much greater later in the pregnancy, at over 13 times the risk in the non-pregnant population. 2009 H1N1 infection was associated with substantial maternal and perinatal morbidity and mortality.

 

Our results show that indigenous pregnant women in Australia and New Zealand were at higher risk of critical illness due to 2009 H1N1 influenza than non-indigenous pregnant women, consistent with the observation that women from indigenous populations are at higher risk for a variety of complications of pregnancy associated with poor maternal and neonatal outcomes.20 21 22

 

Over half of the women had a coexisting illness. Pre-existing asthma occurred in 21% of these women compared with 12% in the general Australian birthing population.23 Among the critically ill women, 42% had a body mass index of more than 30 and 22% of more than 35; the corresponding proportions in the Australian birthing population are 24% and 10%.24 This is consistent with a preliminary report that identifies obesity as a risk factor for 2009 H1N1 related critical illness in pregnant women in the United Kingdom.2

 

For those with access to the full contents of the BMJ, there is an accompanying editorial by Stephen E Lapinsky, associate professor of medicine.

 

 

Critical illness as a result of influenza A/H1N1 infection in pregnancy

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Australia: Pregnancy And Flu

 

 

# 4292

 

From almost the start of the pandemic of 2009, it was apparent that pregnant women were at particularly high risk of complications from this virus.   

 

That is something that has been seen in pandemics past, although it isn’t considered as much of a factor with seasonal flu.

 

In a Perspective, written by 3 CDC physicians (Sonja A. Rasmussen,  Denise J. Jamieson, Joseph S. Bresee) and published in the CDC Journal of EID article, Pandemic Influenza and Pregnant Women in February of 2008, we get this assessment of the historic impact of influenza on pregnant women.

 

Although appropriate nonpregnant control groups were generally not available, mortality rates among pregnant women in the pandemics of 1918 and 1957 appeared to be abnormally high (5,7). Among 1,350 reported cases of influenza among pregnant women during the pandemic of 1918, the proportion of deaths was reported to be 27% (5).

 

Similarly, among a small case series of 86 pregnant women hospitalized in Chicago for influenza in 1918, 45% died (6). Among pregnancy-associated deaths in Minnesota during the 1957 pandemic, influenza was the leading cause of death, accounting for nearly 20% of deaths associated with pregnancy during the pandemic period; half of women of reproductive age who died were pregnant

 

Additionally, these authors write:

 

Associations between maternal influenza infection and childhood leukemia (23), schizophrenia (24), and Parkinson disease (25) have been suggested by some studies. Even if the influenza virus does not have a direct effect on the fetus, fever that often accompanies influenza infection could have adverse effects.

 

Today, with the approach of a new flu season women in Australia are being reminded of the dangers of the H1N1 influenza virus, and urged to get vaccinated against it.   

The article below refers to an eMJA study I covered back in November in a blog entitled Australian Study: H1N1 Hospitalized Patients.

 

 

Pregnant women warned over swine flu

JULIA MEDEW

January 27, 2010

PREGNANT women are being warned to protect themselves against a second wave of swine flu expected in coming months after research confirmed they were more prone to serious illness compared with other healthy people.

 

The first major review of 112 people admitted to seven Melbourne hospitals with the virus last year found that 13 per cent of the patients were pregnant or had just given birth.

 

The research published in the Medical Journal of Australia also found that two patients had suffered rare complications of influenza including Guillain-Barre syndrome, a debilitating form of paralysis, and rhabdomyolysis, a muscle-melting condition.

 

Justin Denholm, a research fellow at the Royal Melbourne Hospital who worked on the project, said both conditions could be seen in people with seasonal flu, but were very rare.

 

(Continue . . . )

 

 

The evidence thus far has supported the idea that the flu shot is safe and beneficial for pregnant women and their unborn children.  

 

A few blogs on that include:

 

Hong Kong: No Increase In Fetal Death Among Vaccine Recipients

NEJM: Pregnancy and Postpartum Risks Of Novel H1N1 Infection

UK: DOH Urges Doctors To Reassure Pregnant Women About Vaccine

IDSA: Studies Show Flu Vaccine Benefits For Pregnant Women

»» Read More

NEJM: Pregnancy and Postpartum Risks Of Novel H1N1 Infection

 

 

# 4189

 

Very early on in the pandemic outbreak of 2009 it became apparent the pregnant women faced higher risks for complications than did otherwise healthy members of the general public. 

 

Intensive care units in the US, and around the world, reported roughly 6% of their admissions of H1N1 patients were of pregnant women, and we’ve seen reports that pregnant women are between 5 and 6 times more likely to die from H1N1 influenza.

 

This is, quite sadly, something that has been observed during pandemic outbreaks of the past; including 1957 and 1918. 

 

Some blogs over the past six months dealing with issues of pregnancy and influenza include:

 

Australian Study: H1N1 Hospitalized Patients

UK: DOH Urges Doctors To Reassure Pregnant Women About Vaccine

Pregnancy & Flu: A Bad Combination

Lancet Study: Pregnancy And H1N1

Branswell On Swine Flu And Pregnancy Complications

 

 

While some of these complications may be caused by structural issues (increased abdominal pressure on internal organs and the diaphragm), some of it probably comes from the mother’s down-regulated immune system, something the pregnant woman’s body does to avoid rejecting the fetus.

 

Today, in the NEJM (New England Journal of Medicine) we get fresh analysis of severe H1N1 influenza infection in pregnant women . . . and postpartum women who had delivered in the previous two weeks.  

 

First however, from CIDRAP news, Maryn McKenna brings us an excellent summary of the NEJM article.

 

H1N1 poses grave risk to pregnant women, new moms

Maryn McKenna Contributing Writer

Dec 23, 2009 (CIDRAP News) – Infection with H1N1 influenza poses a grave danger to pregnant women and those who have just delivered, and the risk increases when they do not receive antiviral treatment very rapidly, California and Atlanta researchers report today online ahead of print in the New England Journal of Medicine.

 

"This pandemic has the potential to notably increase overall maternal mortality in the United States in 2009," they write.

 

In surveillance data gathered by the California Department of Public Health between April and August 2009, early in the H1N1 pandemic, 22 of 102 pregnant and postpartum women who had been hospitalized for flu symptoms needed to be admitted to an intensive care unit (ICU), 16 were put on ventilators, and 8 died.

(Continue . . . )

 

 

Below you’ll find the link to the NEJM study. 

 

 

Severe 2009 H1N1 Influenza in Pregnant and Postpartum Women in California

Janice K. Louie, M.D., M.P.H., Meileen Acosta, M.P.H., Denise J. Jamieson, M.D., M.P.H., Margaret A. Honein, Ph.D., M.P.H., for the California Pandemic (H1N1) Working Group

ABSTRACT

Background Like previous epidemic and pandemic diseases, 2009 pandemic influenza A (H1N1) may pose an increased risk of severe illness in pregnant women.

Methods Statewide surveillance for patients who were hospitalized with or died from 2009 H1N1 influenza was initiated by the California Department of Public Health. We reviewed demographic and clinical data reported from April 23 through August 11, 2009, for all H1N1-infected, reproductive-age women who were hospitalized or died — nonpregnant women, pregnant women, and postpartum women (those who had delivered 2 weeks previously).

<SNIP>

Conclusions 2009 H1N1 influenza can cause severe illness and death in pregnant and postpartum women; regardless of the results of rapid antigen testing, prompt evaluation and antiviral treatment of influenza-like illness should be considered in such women. The high cause-specific maternal mortality rate suggests that 2009 H1N1 influenza may increase the 2009 maternal mortality ratio in the United States.

 

(Continue . . . )

 

»» Read More