(15) Adverse Obstetrical Outcomes are Increased in Adolescent Pregnancy

Background: Adolescent pregnancy is defined as pregnancy before the age of 20 and is the leading cause of mortality in girls ages 15 to 19 worldwide. Adolescent pregnancies are associated with increased maternal, obstetric, and neonatal risks, however data is limited. Our objective was to compare the risk of adverse obstetrical outcomes in teenage pregnancies to adult pregnancies.

Methods: We conducted a population-based retrospective cohort study using a linked maternal-infant database of livebirths in Florida from 2000 to 2019. Inclusion criteria included singleton pregnancies with complete pregnancy and delivery information. Outcomes of interest included preterm birth (PTB), premature rupture of membranes (PROM), hypertensive disorders of pregnancy (HTNP), fetal growth restriction (FGR), cesarean births (CB), adequate prenatal care, and postpartum hemorrhage (PPH). Modified Poisson regression was used to calculate adjusted relative risks (aRR) and 95% confidence intervals (CI) representing the association between maternal age groups and adverse obstetrical outcomes, using ages 25-29 as the reference group. A p-value < 0.05 was considered statistically significant.

Results: Of the 3,616,879 deliveries included in the study, adolescent pregnancy (10-19 year olds) comprised 8.1% of deliveries. Demographic and clinical characteristics by maternal age are presented in Table 1. Teenage pregnancies had higher rates of PTB (10-14 year olds aRR: 1.65, 95% CI: 1.51-1.79; 15-19 year olds aRR: 1.20, 95% CI: 1.18-1.21) and FGR (10-14 year olds aRR: 1.22, 95% CI: 1.01-1.48; 15-19 year olds aRR: 1.28, 95% CI: 1.25-1.32) compared to 25-29 year olds. However, they were less likely to have a CB (10-14 year olds aRR: 0.59, 95% CI: 0.55-0.63; 15-19 year olds aRR: 0.64, 95% CI: 0.64-0.65) and have adequate prenatal care (10-14 year olds aRR: 0.60, 95% CI: 0.57-0.63; 15-19 year olds aRR: 0.83, 95% CI: 0.82-0.83). Younger teen deliveries (10-14 year olds) had an increased risk of HTNP (aRR: 1.15, 95% CI: 1.06-1.26) and those in the older teen delivery group (15-19 year olds) had an increased risk of PPH (aRR:1.14, 95% CI: 1.11-1.17). Complete results are presented in Table 2.

Conclusions: Adolescent mothers are at increased risk for adverse obstetrical outcomes such as FGR and PTB. HTNP is selectively increased in those deliveries with maternal age < 15 year of age, while PPH is increased in deliveries of mothers 15-19 years of age. Teenagers are less likely to have adequate prenatal care and have a CB. These results suggest that tailoring prenatal and intrapartum care in teenage pregnancies may be warranted, however larger studies are needed to corroborate our findings.