Probiotics Are Safe During Pregnancy
Yes, probiotics are safe for use during pregnancy and lactation, with extensive evidence showing no increased risk of adverse maternal or fetal outcomes.
Safety Profile
The safety of probiotics during pregnancy is well-established through multiple systematic reviews and meta-analyses:
No adverse fetal outcomes have been reported with probiotic use during pregnancy, including no effects on Caesarean section rates (OR 0.88; 95% CI 0.65-1.19), birth weight (weighted difference 45g; 95% CI -181 to 271), or gestational age (weighted difference 0.4 weeks; 95% CI -0.4 to 1.2) 1.
A comprehensive 2021 systematic review confirmed that probiotic and prebiotic products are safe for use during pregnancy and lactation, with adverse effects not posing any serious health concerns to mother or infant 2.
Probiotics are rarely systemically absorbed when used by healthy individuals, and multiple randomized controlled trials conducted during the third trimester showed no increase in adverse fetal outcomes 3.
Probiotics are unlikely to be transferred into breast milk, making them safe during lactation 3.
Specific Strains and Considerations
Lactobacillus and Bifidobacterium species are the most extensively studied and proven safe:
These strains have been evaluated in multiple trials with no reported malformations in the probiotic group 1.
The AGA guidelines support the use of specific Lactobacillus and Bifidobacterium combinations in preterm infants, indicating their safety profile extends to vulnerable populations 4.
Minor adverse effects are uncommon but may include:
- One study reported increased vaginal discharge and changes in stool consistency (RR 3.67; 95% CI 1.04-13.0) with Lactobacillus rhamnosus and L. reuteri, though these effects were not clinically significant 2.
Important Caveat
Saccharomyces species (such as S. boulardii) have unknown safety during pregnancy due to lack of published studies 3, 1. While S. boulardii is commonly used for diarrhea treatment, pregnant women should avoid this strain until safety data becomes available.
Clinical Benefits During Pregnancy
Beyond safety, probiotics offer potential therapeutic benefits:
Reduction in vaginal GBS colonization: Probiotic supplementation, particularly when started after 30 weeks of gestation, reduced GBS colonization (OR 0.41; 95% CI 0.21-0.78) 5.
Treatment of vaginal infections: Probiotics showed an 81% reduction in genital infection risk (RR 0.19; 95% CI 0.08-0.48) 6.
Practical Recommendation
Use Lactobacillus and/or Bifidobacterium species probiotics freely during pregnancy and lactation for gastrointestinal symptoms, vaginal health, or general wellness. Avoid Saccharomyces species until safety data emerges. The evidence consistently supports safety across all trimesters and during breastfeeding, with no meaningful risk to mother or infant 2, 1.