Breech presentation at term and associated obstetric risks factors—a nationwide population based cohort study
INTRODUCTION Breech presentation is linked to abnormal pregnancy outcomes. However, the causality of this association is unknown. We aimed to investigate predictors of term breech presentation and pregnancy outcomes of breech presentation. MATERIAL AND METHODS Using a Hungarian registry, all term (≥ 37 weeks), singleton pregnancies with cephalic, and breech presentation in 1996-2011 were analyzed (n = 41 796). Covariates were maternal medical history and data on the present pregnancy. Multivariable logistic regression was used to investigate predictors of breech presentation and of delivery (cesarean section or other obstetrical interventions at birth) and fetal outcomes (Apgar score ≤ 7, need for perinatal intensive treatment, intrauterine death or perinatal mortality) related to breech presentation. RESULTS Breech presentation was independently associated with older maternal age, medical history (primiparity, stillbirth, spontaneous abortion, hormone treatment, and assisted reproduction), maternal morbidities (hypertension and oligohydramnios), and the fetal factors (female sex, younger gestational age at delivery, developmental abnormalities, small for gestational age, and birthweight). An adverse delivery outcome was 11.7 times (95% confidence interval 11.3-12.0) and an adverse fetal outcome was 1.39 times (95% confidence interval 1.33-1.45) more frequent in pregnancies with breech presentation compared with cephalic presentation. Further adjustment for predictors of breech presentation had no major effect on the delivery outcome, but it reduced the risk of adverse fetal outcome (odds ratio 1.18, 95% confidence interval 1.14-1.24). CONCLUSIONS Breech presentation is a marker of pathological pregnancy and is independently associated with an increased risk of gestational complications. Closer surveillance and appropriate management of pregnancies with breech presentation is warranted to prevent adverse perinatal outcomes.