The risk of delayed lactation after giving birth was twice as great among women in the study taking selective serotonin reuptake inhibitor (SSRI) antidepressants as among new mothers who did not take the drugs.
Just eight, or about 2%, of the 431 study participants were taking the antidepressants, however, so the findings are far from conclusive.
But the study is the first to explore the impact of antidepressant use on lactation in humans.
“Delayed lactation is very common in the United States, but we don’t really understand the reasons for it,” researcher Nelson D. Horseman, PhD, of the University of Cincinnati College of Medicine tells WebMD. “This may end up being one of the few concrete explanations for at least some of the delayed lactation we see.”
Serotonin Involved in Breast Function
Earlier research in Nelson’s lab found that the hormone serotonin plays a role in breast function, including the ability to secrete milk when needed.
The finding led the researchers to wonder if drugs that affect serotonin levels, such as SSRI antidepressants, would also affect the ability of the breasts to secrete milk when needed.
SSRIs are the most widely prescribed antidepressants. They include the drugs Zoloft, Celexa, Prozac, Paxil, and Lexapro.
In an effort to answer the question, Nelson and colleagues followed 431 first-time mothers from childbirth through the first days of motherhood.
For the purposes of the study, the researchers considered breastfeeding delayed when a woman did not have copious milk production within three days, or 72 hours, of giving birth.
All the women in the study were eventually able to breastfeed, whether they were taking antidepressants or not.
But the average time to lactation for the eight women taking SSRIs was almost 86 hours after childbirth, which was almost a day later than the average time it took women who did not take the antidepressants to establish a milk supply.
Lactation specialist Laurie Nommsen-Rivers, PhD, tells WebMD that this extra day can be the difference between success or failure for women anxious to provide their babies nutrition.
A co-author of the study, Nommsen-Rivers is also an epidemiologist with Cincinnati Children’s Hospital Medical Center. “That delay can be the point where many women throwing in the towel and decide they can’t breastfeed,” she says. “It is important to point out that all the women in our study eventually lactated. SSRI use doesn’t prevent women from breastfeeding, but it might take SSRI users a little longer.”
Support for New Moms
Nommsen-Rivers says that while all new moms should have access to breastfeeding support, such support may be especially important for new moms who take antidepressants.
The study appears in the February issue of the Journal of Clinical Endocrinology and Metabolism.
“These women need to know that delay doesn’t mean it isn’t going to happen,” she says.
Texas Tech University Medical School health psychologist and lactation consultant Kathleen Kendall-Tackett, PhD, points to numerous studies that have explored the impact of SSRIs on babies born to women who use them.
“To my knowledge this lactation delay has not been documented before,” she tells WebMD. “I would guess that if this is happening, it is rare.”
She points out that pregnant women are at the highest risk for depression in their last trimester and in the early weeks after giving birth.
While she feels too many women may be taking antidepressants when other treatments might work for them, Kendall-Tackett also warns that moms-to-be and new moms should never stop taking SSRIs or any other prescribed antidepressant without their doctor’s approval.
“Generally speaking, if a woman is on an antidepressant during the last trimester of pregnancy she probably needs to stay on it, and she should never go off it on her own,” she says.