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Study: Pregnancy Stress Could Weaken Baby’s Immune System


Stressed out and expecting? Better schedule a spa day — or two or three!

New research out of the University of Rochester Medical Center shows that babies born to moms who were highly anxious while pregnant had suppressed immune system responses to vaccinations at 6 months old.

Researchers behind the study, slated for publication in the journal Brain, Behavior and Immunity, interviewed moms-to-be at 20 and 32 weeks gestation about their anxiety levels and also measured a stress hormone in their saliva. After delivery, the women’s infants were tested for immune response to the Hepatitis B vaccine — routinely given in three doses: a few days after birth, at 2 months and at 6 months.

Plus: Emotional Support During Pregnancy

While the babies showed no link between mom stress and immune system response at 2 months, by 6 months babies of high-stress mamas who had not received their third dose of the vaccine showed a weaker immune response than the babies whose moms had been more zen during pregnancy. The more stressed out their moms had been, the bigger the effect on the babies’ immune system.

Plus: 15 Ways to Have a Great Pregnancy

Don’t panic more if you’re already worrying your way through your 40 weeks, says study researcher Tom O'Connor, a professor of psychiatry at the University of Rochester Medical Center. Once the high-stress babies received their full dosage, the immune system effect disappeared. “It's not as if the experience of stress is going to be more powerful than an immunization,” O'Connor told LiveScience.

Sounds like a good excuse for some R&R anyway — you’re worth it!