Introduction: Rapid repeat pregnancy (RRP), defined as a birth occurring within 33 months of a previous birth, has been associated with increased risk of adverse outcomes including preterm birth, low birthweight, pre-eclampsia and stillbirth. Few studies have examined the impact of RRP in adolescents, yet 25-35% of adolescents who experience one pregnancy will experience an RRP. The current study examines trends and outcomes of adolescent RRP in the Canadian context.
Methods: Using population-based data from CIHI’s Discharge Abstract Database, we linked maternal and newborn records from labour and delivery hospitalizations across Canada (excluding Quebec) from fiscal years 2004/05-2014/15. Women were included if they were less than 20 years old at the index birth event and if they delivered an infant during the study period. Absolute rates of each outcome were calculated; differences between groups were assessed using chi-squared tests. Linear tests for trend were used to assess change over time. Conditional logistic regression models were used to ascertain odds of adverse maternal and neonatal outcomes for RRPs compared to first pregnancies.
Results: Overall, we captured 67,957 adolescent pregnancies in Canada during the study period. Of these, 32.9% (95%CI:32.5-33.2%) represented an RRP. Rates of RRP were higher among 18-19 year-olds (34.1%,95%CI:33.6-34.5%) compared to 15-17 year-olds (30.4%,95%CI:29.7-31.0%). There was substantial variation in RRP rates across provinces, ranging from 24.5% (95%CI:23.6-35.6%) in British Columbia to 47.3% (95%CI:46.1-48.4%) in Manitoba. Girls who experienced an RRP did not have increased odds of maternal or neonatal morbidity in their second pregnancy compared to their first; however, they had decreased odds of having a small-for-gestational-age birth in their second pregnancy (p<0.001).
Conclusion: Adolescent girls who experience a pregnancy are at high risk of experiencing an RRP. Provincial variation in sexual health education and accessibility of contraception may have differential effects on RRP in adolescents.
Suzanne Tough– Professor, Department of Paediatrics, University of Calgary, Calgary, AB
Catherine Scott– Chief Knowledge & Policy Officer, University of Calgary
Anne-Marie McLaughlin– Associate Professor, Dept of Social Work, University of Calgary
Amy Metcalfe– Associate Professor, Department of Obstetrics and Gynecology, University of Calgary, Calgary, AB