Is Pristiq (desvenlafaxine) safe to take during pregnancy?

Is Pristiq (Desvenlafaxine) Safe During Pregnancy?

Pristiq can be continued during pregnancy when the benefits of treating maternal depression outweigh potential risks, as untreated depression poses significant dangers to both mother and fetus, though you should monitor closely for neonatal complications and consider the limited safety data compared to other antidepressants. 1

Key Safety Considerations

What the FDA Label States

The FDA drug label for desvenlafaxine indicates no published studies exist specifically on desvenlafaxine in pregnant women, though epidemiologic studies of venlafaxine (the parent compound) have not shown a clear association with adverse developmental outcomes. 1 The label emphasizes that untreated depression during pregnancy carries its own substantial risks—women who discontinue antidepressants are more likely to experience relapse of major depression compared to those who continue treatment. 1

Specific Risks to Monitor

Maternal Risks:

• Increased risk of preeclampsia with SNRI exposure in mid-to-late pregnancy 1
• Increased risk of postpartum hemorrhage with SNRI exposure near delivery 1

Neonatal Risks:

• Third-trimester exposure may cause neonatal complications requiring prolonged hospitalization, respiratory support, and tube feeding (drug discontinuation syndrome) 1
• The FDA recommends monitoring all neonates exposed to desvenlafaxine in the third trimester 1

Evidence from Related Compounds

Since desvenlafaxine is the active metabolite of venlafaxine, data on venlafaxine is relevant:

• A 2001 prospective controlled study of 150 pregnancies exposed to venlafaxine found no increased rate of major malformations above the baseline 1-3% (only 2 of 125 live births had major malformations), with no significant differences compared to SSRI-exposed or non-teratogenic drug-exposed controls 2

• However, a 2020 large case-control study found venlafaxine was associated with the highest number of birth defects among antidepressants studied, with particularly elevated associations for anencephaly and craniorachischisis (aOR 9.14) that persisted even after accounting for underlying maternal conditions 3

The Clinical Dilemma

This represents contradictory evidence that requires careful interpretation. The older venlafaxine study 2 showed reassuring results, but the more recent and larger 2020 study 3 raises concerns. Given that the 2020 study is more recent, larger, and specifically examined multiple birth defects systematically, its findings carry more weight.

Practical Management Algorithm

For women already on Pristiq when pregnancy is discovered:

• Continue the medication if depression is moderate-to-severe, as discontinuation risks maternal relapse 1
• Do not abruptly stop—this increases relapse risk dramatically 1
• Implement enhanced monitoring (see below)

For women planning pregnancy:

• Consider switching to an antidepressant with more robust pregnancy safety data (such as certain SSRIs) before conception, as medications with more pregnancy safety data are preferable when starting new treatment 4
• If switching is not feasible due to treatment response, continue Pristiq with informed consent about limited data

For women starting treatment during pregnancy:

• Choose an alternative antidepressant with better-established safety profiles first 4
• Reserve Pristiq for cases where other antidepressants have failed

Monitoring Protocol

Throughout pregnancy:

• Screen for preeclampsia signs (blood pressure, proteinuria) especially in second and third trimesters 1
• Assess for gestational diabetes, as some evidence suggests antidepressants may increase this risk 5

Near delivery:

• Alert obstetric team about SNRI exposure for postpartum hemorrhage risk 1
• Prepare neonatal team for potential withdrawal symptoms 1

Neonatal period:

• Monitor newborn for at least 48-72 hours for respiratory distress, feeding difficulties, jitteriness, irritability, and temperature instability 1
• These symptoms typically resolve within 2 weeks but may require supportive care 1

Critical Pitfalls to Avoid

• Do not discontinue abruptly without psychiatric consultation—the risk of untreated maternal depression (including premature birth and decreased breastfeeding initiation) often exceeds medication risks 4
• Do not assume all antidepressants carry equal risk—the 2020 data suggests venlafaxine/desvenlafaxine may have higher associations with certain birth defects than other options 3
• Do not fail to document informed consent about limited safety data and potential risks versus benefits of treatment versus no treatment 1

Pregnancy Registry

Healthcare providers should register patients by calling the National Pregnancy Registry for Antidepressants at 1-844-405-6185 to contribute to the safety database. 1