Acyclovir Dosing for Varicella in Pregnancy
Intravenous acyclovir at 10-15 mg/kg every 8 hours is recommended for pregnant women with severe varicella complications such as pneumonitis. 1
Indications for Acyclovir in Pregnant Women with Varicella
Acyclovir is not routinely recommended for all pregnant women with varicella but should be used in specific circumstances:
- Intravenous acyclovir (10-15 mg/kg every 8 hours for 5-10 days) is indicated for pregnant women with significant varicella complications, particularly pneumonitis 1
- Oral acyclovir (800 mg 5 times daily) can be considered for less severe but significant varicella infections in pregnancy 1
- Treatment should ideally be started within 24-72 hours of rash onset for maximum effectiveness 1
Risk Assessment and Management
The approach to varicella in pregnancy should be based on severity of infection:
- For mild, uncomplicated varicella in pregnancy, routine acyclovir is not recommended 2
- For pregnant women at increased risk of moderate to severe varicella, acyclovir should be considered 2
- For severe complications (especially pneumonia), hospitalization and intravenous acyclovir are strongly indicated 1
Safety Considerations in Pregnancy
- Acyclovir is classified as FDA Category B in pregnancy 2
- A registry of 596 infants exposed to acyclovir during first trimester showed no increased rate of birth defects compared to general population 2
- The American Academy of Pediatrics has not recommended routine use of oral acyclovir for all pregnant women with varicella, but supports its use for serious complications 2
Important Caveats and Considerations
- Acyclovir treatment is most effective when initiated within 24 hours of rash onset 2
- Acyclovir does not reduce transmission of varicella or duration of illness, but reduces severity of symptoms 2
- For exposure to varicella in susceptible pregnant women, varicella zoster immune globulin (VZIG) should be administered within 96 hours of exposure 1
- Recent evidence suggests oral aciclovir may be as effective as VZIG for post-exposure prophylaxis in pregnant women 3
Monitoring and Follow-up
- Pregnant women who develop varicella should receive detailed ultrasound and appropriate follow-up to screen for potential fetal consequences 1
- Neonatal healthcare providers should be informed of peripartum varicella exposure to optimize early neonatal care 1
- If maternal disease onset occurs between 5 days before and 2 days after delivery, VZIG should be administered to the neonate 1
While acyclovir is not routinely recommended for all cases of varicella in pregnancy, it plays a critical role in managing severe infections and potentially reducing maternal and fetal morbidity and mortality when used appropriately at the correct dosage.