Maternal and neonatal outcomes of adolescent pregnancy in Türkiye: a 14-year retrospective cohort study

Studies comparing adolescent and adult pregnancies seldom distinguish the effects of maternal age from those of parity or advanced maternal age. We therefore re-extracted all study variables and compared age groups using an analytical design that addressed both sources of confounding. We reviewed deliveries at one tertiary centre (2011–2024). Adolescence was maternal age ≤ 19 years (World Health Organization); the comparison group comprised women aged 20–34 years; multiple pregnancies were excluded. Parity, smoking, previous cesarean delivery, and four antenatal screening procedures were re-extracted from free text; size for gestational age was recalculated against the Fenton 2013 reference. Models were adjusted for diabetes mellitus, chronic maternal disease, and calendar year, then also for smoking and parity, and repeated in nulliparous women. Of 5683 deliveries, 289 were retrieved and 9 multiple pregnancies excluded, leaving 143 adolescents (97.9% under 18 years) and 103 women aged 20–34 years. Adolescents were more often nulliparous (92.4% vs 37.5%) and less often had a previous cesarean delivery (4.2% vs 35.9%), cesarean delivery (39.9% vs 68.0%), or perinatology follow-up (2.1% vs 13.6%; all p < 0.001). Diabetes mellitus (7.0% vs 15.5%; p = 0.032) and chronic maternal disease (4.2% vs 13.6%; p = 0.008) were commoner in the comparison group. Detailed second-trimester ultrasonography was documented in 17.1% versus 71.7% and first-trimester screening in 22.6% versus 67.8% (both p < 0.001). Any neonatal intervention was less frequent among neonates of adolescents (adjusted odds ratio 0.29, 95% CI 0.15–0.56), persisting in every adjusted model, including within nulliparous women. Small-for-gestational-age birth was more frequent in absolute terms (22.1% vs 14.0%), but not independently so: the odds ratio fell from 1.74 crude to 1.21 (0.47–3.14) fully adjusted and ranged from 1.07 to 2.17 across thirteen specifications; 80% power was reached only for an odds ratio of about 2.5. Nearly all adolescents were under 18 years. Documented uptake of detailed second-trimester ultrasonography and first-trimester screening was three- to fourfold lower among adolescents, the most robust and directly actionable finding. Otherwise, adolescent pregnancies were marked by nulliparity and a lower cesarean delivery rate rather than greater maternal comorbidity. The small-for-gestational-age excess was not independent of parity or calendar year and varied across specifications. Not applicable.