A large claims-based analysis using MarketScan Commercial Claims and Encounters data (2013–2021) examined 24,200 pregnancies with prescription stimulant exposure (amphetamine- or methylphenidate-containing medications). The dataset spans more than 30 million lives across over 100 health plans. Exposure timing was categorized as pre-conception only, first-trimester-only exposure, or continued exposure into the second and third trimesters.
Within the exposed cohort, 6,113 pregnancies (25.3%) had stimulant exposure only before conception. Eighteen thousand eighty-seven pregnancies (74.7%) had exposure during pregnancy; of these, 10,266 (56.8%) discontinued stimulant treatment in the first trimester and 7,821 (43.2%) continued treatment into the second or third trimester. Each exposure group was compared with a matched cohort of pregnancies without stimulant exposure. Outcomes assessed included spontaneous abortion, ectopic pregnancy, stillbirth, placental abruption, pre-eclampsia, gestational hypertension, small-for-gestational-age infants, and preterm birth.
When stimulant use was limited to the first trimester, stimulant-exposed pregnancies were not at increased risk for most adverse outcomes compared with unexposed pregnancies. In fact, the study reported lower rates of some outcomes among first-trimester-only exposed pregnancies, including reductions in spontaneous abortion, preterm birth, and small-for-gestational-age infants relative to unexposed pregnancies.
The authors suggest that improved ADHD symptom control in early pregnancy could support better engagement with prenatal care and healthier maternal behaviors, which may indirectly improve obstetric outcomes. However, the observational design limits causal inference about whether early stimulant treatment itself produces these apparent protective associations.
Continuation of stimulant treatment into the second and third trimesters was associated with higher rates of several adverse outcomes. Compared both with unexposed pregnancies and with pregnancies that had first-trimester-only exposure, continued exposure showed increased risks for hypertensive disorders of pregnancy, pre-eclampsia, placental abruption, preterm birth, stillbirth, and small-for-gestational-age infants.
Direct comparisons between continued-exposure pregnancies and first-trimester-only pregnancies yielded the following reported relative risks (RR) and 95% confidence intervals (CI):
The study found no significant difference between groups for gestational hypertension in these comparisons.
The investigators note biological plausibility for the observed associations. Prescription stimulants can increase blood pressure and induce vasoconstriction, which could reduce uteroplacental blood flow and contribute to hypertensive disorders, placental abruption, fetal growth restriction, and preterm birth when exposure continues throughout pregnancy.
A key competing explanation is confounding by indication. Women who continue stimulant treatment during pregnancy may differ from those who discontinue in clinically meaningful ways: they may have more severe ADHD, higher levels of psychiatric comorbidity (for example, anxiety or depression), different health behaviors, or differing engagement with prenatal care. These unmeasured or incompletely measured factors could independently increase the risk of adverse obstetric outcomes. Prior literature has linked maternal depression and anxiety to outcomes such as preterm birth and hypertensive disorders of pregnancy.
The study used propensity-score matching to reduce measured confounding, but propensity methods cannot eliminate bias from unmeasured variables (for example, ADHD severity, stimulant dose, clinician decision-making, or social and behavioral determinants). Therefore, the reported associations cannot establish causality.
This analysis contributes to the evolving evidence base on ADHD medication use in pregnancy. The principal messages from the study are:
First-trimester-only stimulant exposure was not associated with increased risk for most adverse outcomes and was associated with lower rates of some outcomes compared with unexposed pregnancies.
Continued stimulant exposure into the second and third trimesters was associated with a modestly increased risk of several complications, including pre-eclampsia, placental abruption, preterm birth, stillbirth, and small-for-gestational-age infants.
Because the study is observational, these associations do not prove that stimulant medications caused the adverse outcomes. Unmeasured confounding, including differences in ADHD severity, psychiatric comorbidity, medication dose, and health behaviors, may account for some or all of the observed increased risks.
Clinically, decisions about continuing versus discontinuing stimulant treatment during pregnancy should be individualized. Clinicians and patients must weigh potential medication-related risks against the consequences of untreated ADHD, which may include impaired functioning, compromised safety (for example, increased accident risk), difficulty maintaining healthy behaviors and prenatal care, and elevated vulnerability to perinatal mood and anxiety disorders. The authors emphasize the need for further research to disentangle medication effects from underlying patient characteristics.
The source study is Hasan SA et al., Prescription Stimulant Continuation in Pregnancy and Birth Outcomes. J Atten Disord. 2026;30(3):315–328. Details reported in this summary are taken directly from the Women's Mental Health article reviewing that study. No additional studies or data beyond the source article were added.