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 > or =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.