Does young maternal age increase the risk of adverse obstetric, fetal and neonatal outcomes: a cohort study.

ABSTRACT

OBJECTIVE: To determine whether young maternal age is associated with increased risks of adverse obstetric, fetal and perinatal outcomes. STUDY DESIGN: Register-based study using the data from a computerized database of a University Hospital for the years 1994-2001. The study population included 8514 primiparous women aged less than 31 who delivered a singleton infant. Using maternal age as a continuous variable, crude and adjusted relative risks (RRs) were estimated for each maternal and perinatal outcome. RESULTS: Crude and adjusted RRs of anaemia during pregnancy and fetal death consistently increased with younger maternal age. After adjustment for confounding factors, RRs (95% confidence interval) of fetal death and anaemia were respectively 1.37 (1.09-1.70) and 1.27 (1.15-1.40) for a 16-year-old compared to a 20-year-old mother. Younger mothers had significantly decreased risks of obstetric complications (preeclampsia, caesarean section, operative vaginal delivery and post-partum haemorrhage). Higher prevalence of prematurity and low birth weight in infants born to teenagers were not attributable to young maternal age after adjustment for confounding factors. CONCLUSION: In our population, younger maternal age was significantly and consistently associated to greater risks of fetal death and anaemia and to lower risks of adverse obstetric outcomes.