Summary: A large population-based study of more than 1.27 million births clarifies how selective serotonin reuptake inhibitors (SSRIs) used during pregnancy affect both mothers and newborns. The research shows that SSRI exposure is linked with a higher risk of gestational diabetes and early neonatal adaptation problems, while at the same time being associated with a lower risk of very preterm birth, caesarean section and low birth weight. By using sibling comparisons and several control groups, the study separates medication effects from the influence of maternal depression.
The findings indicate that SSRIs have measurable, independent biological effects on fetal and neonatal outcomes. These results highlight the importance of individualized clinical decision-making that balances maternal mental health needs with careful monitoring of pregnancy and newborn health.
Key Facts
- Dual impact on pregnancy: Use of SSRIs during pregnancy was associated with an increased risk of gestational diabetes but a reduced risk of very preterm birth, caesarean section, and low birth weight compared with pregnant women with depression who did not take antidepressants.
- Newborn adaptation: Infants exposed to SSRIs in utero had higher rates of low 1- and 5-minute Apgar scores, breathing difficulties at birth, and need for neonatal or intensive neonatal care; no increased risk of major congenital malformations was observed.
- Independent medication effects: Comparing mothers who discontinued SSRIs before pregnancy with those who continued during pregnancy, and using sibling comparisons, supports that some risks and benefits are linked to the medication itself rather than only to maternal depression or its severity.
Source: University of Turku
Overview
An international research team, led by investigators at the University of Turku and Columbia University, examined national registry data from Finland covering 1,272,587 singleton births between 1996 and 2018. The study compared outcomes for mothers who filled two or more SSRI prescriptions during pregnancy with outcomes for (1) women diagnosed with depression who did not use antidepressants during pregnancy and (2) women who had discontinued SSRI use before becoming pregnant. The researchers also included sibling-pair analyses to account for shared genetic and environmental factors.
The study was designed to determine whether previously reported associations between prenatal SSRI exposure and adverse outcomes reflected the medications themselves or were confounded by maternal depression and its severity. Analyses adjusted for multiple indicators of depression severity and other possible confounders.
Main findings
Compared with women with depression who did not use antidepressants, maternal SSRI use was associated with a modestly increased risk of gestational diabetes (adjusted OR 1.14; 95% CI 1.07–1.22). At the same time, SSRI exposure was associated with lower risks of caesarean section, late preterm birth (32–36+6 weeks), very preterm birth (<32 weeks), small for gestational age (SGA), and both low and very low birth weight.
For newborns, SSRI exposure was linked with elevated odds of a low (<7) 5-minute Apgar score (OR 2.02; 95% CI 1.78–2.30), respiratory difficulties (OR 1.61; 95% CI 1.48–1.75), and need for neonatal care unit (NCU) treatment (OR 1.23; 95% CI 1.16–1.31). Third-trimester exposure further increased the risk of a low 5-minute Apgar score (OR 3.44; 95% CI 2.93–4.04). There was no observed increase in major congenital anomalies; in fact, hospital stays at seven days and major malformations were reported as lower in some comparisons.
When comparing women who discontinued SSRIs before pregnancy with those who continued, SSRI use during pregnancy remained associated with reduced risks of late preterm birth and low birth weight, while increased risks for early neonatal adaptation problems persisted. The sibling analyses, which adjust for familial factors, corroborated an increased risk of gestational diabetes and neonatal complications tied to SSRI exposure.
Clinical implications
Lead author Docent Heli Malm notes that these results underscore the dual nature of SSRI effects in pregnancy: while antidepressant treatment may protect against preterm birth and low birth weight that can be associated with untreated depression, it also appears to increase risks related to neonatal adaptation and maternal metabolic outcomes such as gestational diabetes.
These findings support careful, individualized treatment planning for pregnant people with depression. Decisions about continuing or initiating SSRI therapy during pregnancy should be made in close consultation with healthcare providers, weighing the benefits of treating maternal depression against the potential risks to pregnancy and the newborn. Enhanced monitoring of pregnancy progression, maternal metabolic health, and neonatal adaptation is advisable when SSRIs are used in pregnancy.
Key questions answered
Q: Should I stop taking my antidepressant if I find out I’m pregnant?
A: Medication decisions should be personalized and made with a healthcare provider. This study identifies risks such as gestational diabetes and early neonatal adaptation issues, but also shows that SSRI treatment can reduce risks linked to untreated depression, including preterm birth.
Q: Do SSRIs cause birth defects?
A: The researchers did not find an increased risk of major congenital malformations associated with SSRI exposure.
Q: How do medication effects differ from the effects of maternal depression?
A: Using sibling comparisons and multiple control groups allowed the team to separate medication effects from maternal depression. The study suggests SSRIs contribute independently to neonatal adaptation challenges while also reducing some risks commonly associated with depression, such as low birth weight and preterm delivery.
Editorial notes
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full by the editorial staff.
- Additional context was added by the news team.
About this research
Author: Tuomas Koivula
Source: University of Turku
Contact: Tuomas Koivula, University of Turku
Image credit: Neuroscience News
Original research: SSRI use during pregnancy and maternal depression – a nationwide birth cohort study on risks to the mother and the newborn. Heli Malm et al. American Journal of Obstetrics & Gynecology MFM. DOI: 10.1016/j.ajogmf.2026.101910 (open access).
Abstract
Background: Maternal depression may confound previous associations between SSRI use and adverse pregnancy and neonatal outcomes.
Objective: To determine whether SSRI use during pregnancy is associated with increased risks of pregnancy and neonatal complications after adjusting for indicators of maternal depression severity.
Study design: A national register-based cohort of 1,272,587 singleton live births in Finland (1996–2018). Women with two or more SSRI purchases during pregnancy (N=19,020) were compared to women with a diagnosis of depression but no antidepressant use (N=19,625) and to women who discontinued SSRIs before pregnancy (N=3,145). Analyses adjusted for depression severity indicators and included within-family sibling comparisons.
Results: SSRI use during pregnancy was associated with an increased risk of gestational diabetes and with higher odds of early neonatal adaptation problems (low Apgar scores, breathing problems, and neonatal care). Conversely, SSRI exposure was associated with lower risks of caesarean section, very preterm birth, and low birth weight. These associations persisted after adjustment for depression severity and in sibling analyses.
Conclusions: SSRI treatment during pregnancy appears to affect neonatal adaptation independently of maternal depression and may reduce the risk of preterm birth. The observed association with gestational diabetes warrants further research to clarify mechanisms and implications for clinical care.