Recurrence of breech presentation in consecutive pregnancies

OBJECTIVE: To investigate the recurrence risk of breech presentation at term, and to assess the risk factors that contribute to its recurrence. DESIGN: Cohort study. SETTING: New South Wales, Australia. POPULATION: Women with their first two (n = 113 854) and first three (n = 21 690) consecutive singleton term pregnancies, in the period 1994–2002. METHODS: Descriptive statistics including rates, relative risks and adjusted relative risks, as determined from logistic regression and Poisson analyses. MAIN OUTCOME MEASURES: Rates and risks of occurrence and recurrence of breech presentation at birth in each pregnancy, and maternal and infant risk factors associated with breech recurrence. RESULTS: First-time breech presentation at term occurred in 4.2% of first pregnancy deliveries, 2.2% of second pregnancies and 1.9% of third pregnancies. The rate of breech recurrence in a second consecutive pregnancy was 9.9%, and in a third consecutive pregnancy (after two prior breech deliveries) was 27.5%. The relative risk of breech recurrence in a second pregnancy was 3.2 (95% CI 2.8–3.6), and in a third consecutive breech pregnancy was 13.9 (95% CI 8.8–22.1). First pregnancy factors associated with recurrence included placenta praevia [adjusted relative risk (aRR) 2.2; 95% CI 1.3–3.7], maternal diabetes (aRR 1.4; 95% CI 1.0–2.1) and a maternal age of ≥35 years (aRR 1.2; 95% CI 0.9–1.6). Second pregnancy factors included birth defects (aRR 2.5; 95% CI 1.4–4.2), placenta praevia (aRR 2.5; 95% CI 1.5–4.1) and a female infant (aRR 1.2; 95% CI 1.0–1.5). CONCLUSIONS: The increased recurrence risk of breech presentations suggests that women with a history of breech delivery should be closely monitored in the latter stages of pregnancy.