From the Guidelines
Women taking SNRIs during pregnancy may have a slightly increased risk of postpartum hemorrhage, but the absolute risk remains low, and the benefits of continuing treatment for mental health stability typically outweigh the potential bleeding risks. The mechanism behind this increased risk involves serotonin's role in platelet aggregation and vasoconstriction; SNRIs block serotonin reuptake, potentially impairing these hemostatic functions 1. Healthcare providers should maintain vigilance for excessive bleeding during delivery for women on SNRIs, but don't need to discontinue these medications before delivery in most cases. Instead, ensuring appropriate monitoring during labor and delivery, having uterotonic agents readily available, and maintaining a lower threshold for intervention if bleeding occurs represent prudent approaches.
Some key points to consider in managing postpartum hemorrhage include:
- Keeping the patient warm, as many clotting factors function poorly if the body temperature is less than 36 °C 1
- Avoiding acidosis, as it can exacerbate bleeding
- Rapidly transfusing packed red blood cells, fresh frozen plasma, and platelets in a fixed ratio if bleeding is excessive
- Using point of care testing or having a centralized laboratory for rapid results to facilitate transfusion management
The estimated increased risk of postpartum hemorrhage with SNRIs is approximately 1.5 to 2 times baseline, which translates to a small absolute risk increase given that severe postpartum hemorrhage is relatively uncommon 1. Women with additional risk factors for bleeding may warrant more careful consideration of risks versus benefits. Overall, the management of postpartum hemorrhage should be based on clinical presentation, and healthcare providers should be prepared to intervene quickly if bleeding occurs.
From the FDA Drug Label
Use of duloxetine in the month before delivery may be associated with an increased risk of postpartum hemorrhage [see WARNINGS AND PRECAUTIONS (5. 5)] . Data from a postmarketing retrospective claims-based cohort study found an increased risk for postpartum hemorrhage among 955 pregnant women exposed to duloxetine in the last month of pregnancy compared to 4,128,460 unexposed pregnant women (adjusted relative risk: 1.53; 95% CI: 1.08 to 2. 18).
The use of duloxetine, an SNRI, in the month before delivery may be associated with an increased risk of postpartum hemorrhage. A postmarketing study found an increased risk for postpartum hemorrhage among pregnant women exposed to duloxetine in the last month of pregnancy, with an adjusted relative risk of 1.53 2.
From the Research
Risk of Postpartum Hemorrhage with SNRIs
- The risk of postpartum hemorrhage (PPH) with selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) has been studied in several research papers 3, 4, 5, 6, 7.
- A study published in the Journal of women's health found that SSRI/SNRI exposure was associated with a PPH unadjusted odds ratio of 1.42 compared to no exposure, and an adjusted odds ratio of 1.33 3.
- Another study published in The Journal of clinical psychiatry found that gestational exposure to SSRIs was associated with a significantly increased risk of PPH, with a crude number needed to harm of 48 4.
- A hospital-based cohort study published in the Journal of thrombosis and haemostasis found that women with a vaginal non-surgical delivery who reported use of SSRI during pregnancy had approximately a 2-fold increased risk of both PPH and postpartum anemia 5.
- A population-based cohort study published in Obstetrics and gynecology found that serotonin-norepinephrine reuptake inhibitor exposure in late pregnancy was associated with a 1.6- to 1.9-fold increased risk of postpartum hemorrhage 6.
- A cohort study published in the BMJ found that current exposure to serotonin reuptake inhibitors near delivery was associated with a 1.47-fold increased risk of postpartum hemorrhage, and current non-serotonin reuptake inhibitor exposure was associated with a 1.39-fold increased risk 7.
Key Findings
- The use of SSRIs and SNRIs in late pregnancy may increase the risk of postpartum hemorrhage 3, 4, 5, 6, 7.
- The risk of postpartum hemorrhage may be higher with SNRI exposure than with SSRI exposure 6, 7.
- Women with a history of mood or anxiety disorders who are treated with antidepressants during late pregnancy may be at increased risk of postpartum hemorrhage 7.