Use of SSRIs While Breastfeeding Does Not Affect Children’s IQ Scores, Study Suggests

New mothers who took selective serotonin reuptake inhibitors (SSRIs) during pregnancy and choose to continue such treatment during breastfeeding might have one less thing to worry about, Essi Whaites Heinonen, MD, PhD, of the Department of Pediatrics, Karolinska Institutet Huddinge, Huddinge, Sweden, and co-authors reported in JAMA Network Open.

Their prospective cohort study of nearly 100 mother-child pairs found no meaningful differences in the IQ scores of children whether they were breastfed by a mother receiving SSRIs, breastfed by a mother not receiving SSRIs, or not breastfed at all.

"The main outcomes were the composite scores of Full-Scale (FSIQ), Verbal (VIQ), and Performance IQ (PIQ) measured with the version of WPPSI available at the time of testing, the WPPSI Revised (WPPSI-R) or the WPPSI, Third Edition (WPPSI-III)," the study authors wrote.

"The differences in FSIQ and PIQ scores between breastfed and nonbreastfed children in this SSRI-exposed cohort are of the same magnitude as the positive effects of breastfeeding seen on the cognitive development in the general population and in children exposed to maternal antiepileptic medications. This is, to our knowledge, a novel finding, supporting breastfeeding in mothers in need of treatment with SSRIs," they wrote.

The authors continued, "However, the differences in FSIQ and PIQ between the breastfed SSRI-exposed and the nonbreastfed infants were no longer significant after adjustment for maternal factors, and there was a significant negative correlation between depressive symptoms during pregnancy and child IQ. Hence, these results also support the association between maternal mood disorders and the long-term development of the children described by previous studies."

Based on their results, as well as other research, Heinonen et al wrote, "we conclude that mothers in need of treatment with SSRIs post partum may be encouraged to breastfeed without discontinuation of the treatment."

The study authors noted that "to our knowledge, the association between child cognitive performance and exposure to SSRIs through breastfeeding has not been previously examined. This question is of clinical importance, as some breastfeeding mothers still avoid antidepressant use due to the effects treatment may pose for the breastfed infant."

These concerns are not baseless, Heinonen and colleagues explained: "SSRIs are known to transfer to breast milk," most notably in the cases of fluoxetine hydrochloride, citalopram, and escitalopram.

"Although the level of drug exposure is lower through breastfeeding than through placental transfer," they continued, "there is at least a theoretical risk that the highly lipophilic SSRIs ingested by the breastfed infant could negatively affect the infant’s brain maturation."

The issue, according to the authors, is that breastfeeding is known to improve a child’s cognitive development, among other benefits, which in total might outweigh any harm from SSRI exposure via breast milk.

The non-profit, multistate MotherToBaby network focuses on evidence-based information about the benefits and risks of medications and other exposures during pregnancy and breastfeeding.

This cohort study was conducted as a secondary analysis of a larger MotherToBaby cohort open to any English- or Spanish-speaking women in California.

This analysis was based on participants who enrolled in the California MotherToBaby cohort between May 1989 and April 2008, who received SSRIs in early pregnancy, and whose children were tested with the WPPSI between April 1996 and August 2012. Breastfeeding duration was required to be at least one month.

The mothers in the study cohort of 97 mother-child dyads had a mean age at delivery of 34, and most (86.6%) identified as non-Hispanic White. A large majority (81, or 83.5%) received fluoxetine hydrochloride, as opposed to a different SSRI, during pregnancy.

The mean duration of treatment with SSRIs during pregnancy was 24.2 weeks; mothers who breastfed without SSRI treatment had a significantly shorter mean treatment duration than the two other groups (14.0 weeks vs. 35.0 and 28.0 weeks; P < 0.001).

Fifty-two (53.6%) of the 97 children were female; mean age at cognitive testing was 4.9;. children (22.7%) were exposed to SSRIs with breastfeeding, 37 (38.1%) were breastfed without postnatal SSRI exposure, and 38 (39.2%) were not breastfed.

"Twenty-five mothers (25.8%) were also treated with other psychotropic medications during pregnancy, including significantly fewer of the mothers who breastfed while treated with SSRIs (2 of 22 [9.1%]) than mothers who breastfed without SSRI treatment (8 of 37 [21.6%]) and mothers who did not breastfeed (15 of 38 [39.5%]) (P = 0.03)," the study authors wrote.

The most common other psychotropic medications used during pregnancy were benzodiazepines (16 of 97 mothers [16.5%]), antipsychotics (5 of 97 [5.2%]), and antiepileptic drugs (3 of 97 [3.1%]). None of the 59 breastfeeding mothers reported using any other psychotropic medications.

The mean duration of breastfeeding was 8.4 months.

Heinonen et al wrote, "No participants reported any use of illicit drugs or cannabis during pregnancy, but 14 of 89 with data available (15.7%) reported use of tobacco and 48 of 89 (53.9%) reported use of alcohol at some point during pregnancy, with a significantly higher percentage of mothers who breastfed with and without SSRI use (13 of 22 [59.1%] and 26 of 37 [70.3%]) than mothers who did not breastfeed (9 of 38 [23.7%]) reporting alcohol use during pregnancy."

The three groups did not differ with respect to maternal symptoms of depression, either during pregnancy or at the time of developmental testing.

The cohort-wide mean FSIQ score was 105.8, corresponding to the 62nd percentile; the mean VIQ was 103.9 (58th percentile); and the mean PIQ was 107.0 (64th percentile).

The authors reported, "The adjusted mean FSIQ in children exposed to SSRIs through breastfeeding … was similar to that in breastfed children not exposed to SSRIs through breastfeeding (… P = 0.29) and 6.3 points higher than in nonbreastfed children (… P = 0.046). The adjusted mean PIQ of the breastfeeding-exposed children was not significantly higher than of breastfed children not exposed to SSRIs post partum (… P = 0.12) but 8.1 points higher than the adjusted mean PIQ of nonbreastfed children (… P = 0.03). The differences in mean FSIQ and PIQ between the children exposed to SSRIs through breastfeeding and the nonbreastfed children were no longer statistically significant after further adjustments for factors related to maternal mood during pregnancy."

Adjusted mean VIQ scores were similar across all three exposure groups.

The authors cited standardized face-to-face testing of the infants in the study as its largest strength. Among its limitations were that "the cohort was based on volunteers and may not be representative of the general population."

Heinonen reported grant support from Region Stockholm ALF Medicin 2025 outside the submitted work.

This study was supported by grants from the Swedish Research Council, the Söderström Königska Foundation, the Edith and Erik Fernström Foundation, the Swedish Doctors Association, the Karolinska Institutet Funds, the State of California, the Samaritanean Foundation, Stiftelsen Mjolkdroppen, and the Freemason’s Children’s Welfare Foundation in Stockholm.

Heinonen EW, et al "Cognitive outcomes of children exposed to selective serotonin reuptake inhibitors through breast milk" JAMA Netw Open 2025; DOI:10.1001/jamanetworkopen.2025.44989.