What is the recommended treatment for influenza in pregnant women?

Treatment of Influenza in Pregnant Women

Pregnant women with suspected or confirmed influenza should receive prompt antiviral treatment with oseltamivir, regardless of vaccination status or laboratory test results. 1

Risk Assessment and Importance of Treatment

• Pregnant and postpartum women are at high risk of serious complications from both seasonal and pandemic influenza infections 1, 2
• Pregnancy itself is a high-risk condition that makes the potential adverse effects of influenza particularly serious 1, 3
• Influenza during pregnancy can lead to miscarriages, preterm deliveries, high maternal mortality, small-for-gestational age infants, and neonatal intensive care admissions 2

First-Line Treatment Recommendations

• Oseltamivir (Tamiflu) is the first-line recommended antiviral agent for influenza treatment in pregnant women 1, 4
• Treatment should be initiated presumptively based on clinical evaluation, without waiting for laboratory confirmation 1, 3
• Treatment within 48 hours of symptom onset is ideal, but should not be withheld if this window is missed 1
• Standard adult dosing for oseltamivir is 75 mg twice daily for 5 days 5, 6

Safety Profile of Oseltamivir During Pregnancy

• Available risk-benefit evidence indicates that the benefits of oseltamivir treatment outweigh potential risks during pregnancy 2, 7
• Oseltamivir has been shown to shorten the duration of illness and reduce the likelihood of complications among infected individuals 4, 7
• While oseltamivir may cross the placenta, there is no evidence of adverse fetal outcomes from most in utero exposures to neuraminidase inhibitors 2
• The most common side effects of oseltamivir are nausea and vomiting, which occur in approximately 10% and 9% of patients, respectively 6

Alternative Treatment Options

• Zanamivir can be considered as an alternative to oseltamivir based on current resistance patterns 1
• Zanamivir should be used with caution in pregnant women with underlying respiratory conditions such as asthma 8
• Baloxavir marboxil has been approved for treatment of uncomplicated influenza in outpatients 12 years and older, but data on its use during pregnancy is limited 6

Prophylaxis Considerations

• Post-exposure antiviral chemoprophylaxis can be considered for pregnant women and women who are up to 2 weeks postpartum who have had close contact with infectious individuals 1
• This is particularly important in pandemic settings, especially for non-vaccinated women 2

Prevention Through Vaccination

• Influenza vaccination is strongly recommended for all pregnant women during any trimester 6
• Vaccination protects both the mother and infant through transplacental antibody transfer and breastfeeding 6, 9
• Infants born to vaccinated mothers have a risk reduction of up to 72% for laboratory-confirmed influenza hospitalization in the first few months of life 6, 9
• Breastfeeding further enhances protection through transfer of influenza-specific IgA antibodies 9

Special Clinical Considerations

• Over-the-phone treatment for low-risk patients is preferred to help reduce disease spread among other pregnant patients in clinical settings 1
• Pregnant women with other underlying health conditions are at even greater risk of adverse effects from influenza 1
• Physiologic adaptations of pregnancy may alter the pharmacokinetics of oseltamivir, but standard dosing is still recommended 4, 7

Treatment Algorithm

1. Identify suspected influenza based on symptoms (fever, myalgia, headache, rhinitis, sore throat, cough) 3
2. Do not delay treatment for laboratory confirmation 1, 3
3. Initiate oseltamivir 75 mg twice daily for 5 days 5, 6
4. Consider zanamivir as an alternative if indicated 1
5. Provide supportive care including hydration and fever control 3
6. Monitor for complications and consider hospitalization for severe symptoms 1, 2