WHAT THIS EVIDENCE MEANS FOR PRACTICE
The implementation of CDC guidelines in 2002 had a salutary impact on the burden of neonatal invasive GBS disease. The 2010 updated guidelines address areas of suboptimal compliance. Health institutions should determine where changes need to be made to better adhere to these guidelines, which are readily available online.1
Be vigilant for influenza among your pregnant patients—
and take necessary action
Siston AM, Rasmussen SA, Honein MA, et al, for the Pandemic H1N1 Influenza in Pregnancy Working Group. Pandemic 2009 influenza A(H1N1) virus illness among pregnant women in the United States. JAMA. 2010;303(15):1517–1525.
The recent H1N1 pandemic highlighted the status of influenza as a major public health problem, not only among children and the elderly but especially among pregnant women. This report by Siston and colleagues describes the US experience of the pandemic. To ascertain the severity of infection during pregnancy, the authors analyzed data from 788 pregnant women who developed symptoms of H1N1 infection between April and August 2009. These women were identified through the CDC national surveillance system. Data from an additional 165 women who developed symptoms through December 2011 and who were admitted to an ICU because of influenza were also analyzed.
Siston and colleagues found a high case-fatality rate (5%) among pregnant women who had influenza. Almost one fourth (22.6%) of women who were hospitalized with influenza were admitted to an ICU because of severe illness.
The timing of antiviral treatment influenced the course of the illness. For example, women who received antiviral treatment within 2 days of the onset of symptoms had a significantly lower risk of death (0.5%), compared with women who received treatment within 3 to 4 days (5%) and with women who were treated after 4 days (27%). Women who were not treated at all also had an elevated risk of ICU admission and death, although that risk was not as high as it was among women treated 4 days or longer after the onset of symptoms. This finding suggests that severity of illness may play a role in determining who receives antiviral treatment.
WHAT THIS EVIDENCE MEANS FOR PRACTICE
The high incidence of severe morbidity and death among pregnant women who contract H1N1 influenza is consistent with the findings of several studies, suggesting that pregnant women are especially vulnerable to the virus. Although Siston and colleagues focused on pandemic influenza, which may be more severe than seasonal flu, their data and other studies suggest that pregnant women have increased susceptibility to influenza-like illness during regular flu season (October to May).
More than 10% of pregnant women may have confirmed influenza during flu season, making it one of the most common infections during pregnancy. Therefore, during flu season, providers should maintain a high index of suspicion for viral infection. Antiviral treatment—typically oseltamivir (75 mg orally twice daily) or zanamivir (5 mg inhaled twice daily) for 5 days—should be administered promptly, ideally within 2 days of the onset of symptoms.
If a pregnant woman is exposed to influenza, 10 days of prophylactic antiviral therapy (75 mg oral oseltamivir or 10 mg inhaled zanamivir daily) is indicated.
The CDC makes recommendations annually about which antivirals to use. Oseltamivir and zanamivir are preferred because they cover both types of human influenza (A and B), and 99% of circulating influenza viruses are susceptible to them.
ACOG recently emphasized the high-risk nature of influenza during pregnancy and urged universal vaccination of women who will be pregnant or postpartum during the flu season as “an integral element of prenatal care.”1
ACOG: Give prophylactic antimicrobials before the incision
in cesarean delivery
ACOG committee opinion no. 465: Antimicrobial prophylaxis for cesarean delivery: timing of administration. Obstet Gynecol. 2010;116(3):791–792.
The use of antimicrobial prophylaxis for cesarean delivery is associated with a reduction of 50% or more in the rates of postcesarean infection and severe adverse outcomes, including maternal death. However, there has been some controversy surrounding the question of timing of antimicrobial administration. Should the drugs be administered at the time the cord is clamped or prior to the cesarean skin incision? And, if the latter, just how long before the incision should antimicrobials be given?
ACOG weighed in on this question in September 2010 in a Committee Opinion based on a review of data. It recommended that, whenever feasible, antimicrobials should be administered within 60 minutes before the start of the procedure.
In the past, antimicrobial administration at the time of cord clamping was proposed to reduce fetal exposure and prevent the masking of neonatal infection (falsely negative culture results). However, the data ACOG reviewed from randomized, clinical trials indicate that pre-incision antimicrobials may further reduce the risk of infection (including endometritis and wound infection) without apparent perinatal harm.