Four infants had detectable sertraline (>2 mcg/L) and 11 infants had detectable norsertraline in their serum with an average concentration of 22 mcg/L.
One study of side effects of SSRI antidepressants in nursing mothers found no adverse reactions that required medical attention among 2 infants whose mother was taking sertraline.  However, in a study of cases of hyperprolactinemia and its symptoms (e.g., gynecomastia) reported to a French pharmacovigilance center, sertraline was not found to have an increased risk of causing hyperprolactinemia compared to other drugs. Two side effects possibly related to sertraline in breastmilk have been reported to the Australian Adverse Drug Reaction Advisory Committee. The infant subsequently developed severe constipation with maternal paroxetine use, but tolerated maternal citalopram use. The mother of a preterm infant was taking sertraline 150 mg daily during pregnancy and postpartum. If your little one sleeps all night, feed her before bedtime and put her to sleep. Infant serum levels were measured 2.2 hours (range 0.5 to 5 hours) after nursing. Bolea-Alamanac BM, Green A, Verma G, et al. A mother who was 3 months postpartum was treated for depression with sertraline 50 mg in the morning and olanzapine 1.25 mg at night at night for sleep. She reported an increase in milk supply when she stopped sertraline for one week at 4 months postpartum. Among the two groups who had taken an SSRI, 33 took citalopram, 18 took escitalopram, 63 took fluoxetine, 2 took fluvoxamine, 78 took paroxetine, and 87 took sertraline. Did your new born experience any withdrawal symptoms? A study showed the delay in the onset of lactation when mothers use the drug.
In these women, the concentration in milk correlated with serum concentration, but not daily dosage.  The antidepressants used by the mothers were not specified.A retrospective cohort study of hospital electronic medical records from 2001 to 2008 compared women who had been dispensed an antidepressant during late gestation (n = 575; sertraline n = 200) to those who had a psychiatric illness but did not receive an antidepressant (n = 1552) and mothers who did not have a psychiatric diagnosis (n = 30,535). Of the 247 infants, 154 developed PNA.
Kieviet N, Hoppenbrouwers C, Dolman KM, et al. The symptoms worsened on the 4th day of life, but breastfeeding was continued. 2015;18:139-46.. [PMC free articleMcAllister-Williams RH, Baldwin DS, Cantwell R, et al. Salazar FR, D'Avila FB, de Oliveira MH, et al. Thus, the ingested amount by the baby is very low and is often not detectable … The right foot eventually became darker with blackened toes and he developed gangrene of the right lower limb, which did not respond to medical therapy and required amputation of all five toes and surgical debridement of the metatarsals. Automatically, the baby’s weight would reduce, thus resulting in the mother’s depression. See a medical professional for personalized consultation. All had been breastfeeding for at least 3 weeks.
The infant was later found to have genetically intermediate metabolism of two of the CYP450 enzymes involved in sertraline metabolism. No specific information on maternal sertraline dosage, extent of breastfeeding or infant age was reported. This could delay breastfeeding in infants. 2019;23:383-90.. [PubMedHendrick V, Fukuchi A, Altshuler L, et al. A mother who was exclusively breastfeeding a 2-month-old infant began taking sertraline 50 mg daily for depression. Breastfeeding and Zoloft Risks. Pogliani L, Baldelli S, Cattaneo D, et al.