Teenage pregnancies: obstetric characteristics and outcome

To quantify the age related risk of adverse obstetric outcome in primigravid women less than 20 years of age.

The study sample was drawn from Cardiff Births Survey (a computerized maternity information database) comprising 66,271 pregnancies in the South Glamorgan region during 1990-1999. Pregnancy outcomes of primigravid women were compared in age groups less than 20 years (n=4126) and 20 to <35 years (n=17,615). SPSS version 11 was used for statistical analysis. Student's t-test was used for continuous variables, Chi square, Fishers exact test was used for categorical variables.

There was a lower incidence of multiple pregnancies (OR=0.3(0.2-0.4)), spontaneous rupture of membranes >24h (OR=0.7(0.6-0.9)), and pregnancy-induced hypertension (OR=0.8(0.6-0.8)) amongst teenage primigravidae but a higher incidence of anaemia (OR=1.8(1.6-2.0)), and pyelonephritis (OR=1.5(1.1-2.0)). There was a lower incidence of induction of labour (OR=0.7(0.7-0.8)) and use of regional analgesia in the teenage group. Teenage women were more likely to have a spontaneous vaginal delivery (OR=2.1(2.0-2.3)) with a significantly lower incidence of instrumental delivery (OR=0.5(0.5-0.6)), and Caesarean section (OR=0.4(0.4-0.5)). Inspite of a higher incidence of preterm labour (corrected OR=1.4(1.1-1.7)) the perinatal outcome measures between the teenage group and the older group were not significantly different.

Teenage primigravidae are more likely to have a spontaneous vaginal delivery, without compromising the maternal or neonatal outcome.