Can Paxlovid Be Given to Pregnant Women?
Yes, Paxlovid (nirmatrelvir/ritonavir) can be given to pregnant women with COVID-19 who are at high risk for severe disease, after discussing potential risks and benefits, though data remain limited. 1, 2
Clinical Decision Framework
When to Consider Paxlovid in Pregnancy
Paxlovid should be considered on a case-by-case basis for pregnant women with mild-to-moderate COVID-19 who are at high risk for progression to severe disease, hospitalization, or death. 1, 2
The decision requires thorough discussion with the patient about potential risks and benefits, ideally involving a multidisciplinary team including obstetrics and infectious disease specialists. 1
COVID-19 in pregnancy is associated with serious adverse outcomes including preeclampsia, eclampsia, preterm birth, premature rupture of membranes, venous thromboembolic disease, and fetal death, which must be weighed against theoretical medication risks. 2
Safety Evidence
Human Data
Available data on nirmatrelvir use during pregnancy are insufficient to evaluate for drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. 2
Published observational studies on ritonavir use in pregnant women (from extensive HIV treatment experience with over 3,500 first-trimester exposures) have not identified an increased risk of major birth defects, with a prevalence of 2.4% compared to the background rate of 2.7%. 2
A recent observational study of 30 pregnant women treated with Paxlovid during the Omicron wave showed the medication was effective and safe, with shorter duration of COVID-19 symptoms (10.10 days versus 15.59 days) and no severe adverse events. 3
Animal Data
Animal studies with nirmatrelvir showed no biologically significant developmental effects in rats at doses up to 1,000 mg/kg/day, though reduced fetal body weights were observed in rabbits at systemic exposures 11 times higher than clinical exposure. 2, 4
Embryo-fetal development studies with ritonavir showed no evidence of adverse developmental outcomes in rats and rabbits at systemic exposures 5-8 times higher than clinical exposure. 2
Comprehensive reproductive toxicology studies found no effects on male and female fertility or early embryonic development, consistent with nirmatrelvir's virus-specific target not present in mammalian cells. 4
Common Adverse Effects
Dysgeusia (altered taste) is the most common adverse effect, occurring in approximately 91.7% of pregnant women taking Paxlovid. 3, 5
Diarrhea is also commonly reported. 3
Viral rebound (return of positive test or symptoms) occurred in 50% of pregnant patients in one survey study, though this did not lead to severe outcomes. 5
Important Monitoring Considerations
Close monitoring for adverse effects and pregnancy outcomes is recommended if treatment is initiated. 1
One observational study noted a higher proportion of cesarean deliveries among Paxlovid-treated women (76.92% versus 42.86%), though this may reflect underlying disease severity rather than medication effect. 3
An insignificantly higher rate of small-for-gestational-age newborns was observed in the Paxlovid group (23.08% versus 3.57%), requiring further investigation. 3
Critical Drug Interactions
Paxlovid is contraindicated with numerous medications due to ritonavir's potent CYP3A4 inhibition, including certain sedatives (triazolam, oral midazolam), statins (lovastatin, simvastatin), ergot derivatives, and many others. 2, 6
Combined hormonal contraceptives may be affected by Paxlovid; females of reproductive potential should use alternative or additional barrier contraception during treatment. 2
A comprehensive medication review is essential before prescribing, as ritonavir affects approximately 60% of available medications metabolized by CYP3A4. 6
Practical Prescribing Details
The standard dose is nirmatrelvir 300 mg (two 150 mg tablets) with ritonavir 100 mg (one tablet) taken together twice daily for 5 days. 2
Dose adjustment is required for patients with kidney disease (eGFR 30-60 mL/min: nirmatrelvir 150 mg with ritonavir 100 mg twice daily). 2
Treatment should be initiated as soon as possible after COVID-19 diagnosis and within 5 days of symptom onset. 2
Key Caveats
Unknown risk remains the most common reason pregnant women decline Paxlovid treatment, highlighting the need for improved counseling and public health messaging. 5
Long-term follow-up of pregnant women exposed to Paxlovid and their offspring is needed to fully establish safety. 3, 7
The ritonavir component has extensive safety data from HIV treatment in pregnancy, providing reassurance, though nirmatrelvir-specific pregnancy data remain limited. 1, 7