Congenital anomalies in breech presentation: A nationwide record linkage study.

Our study aimed to determine if congenital anomalies are associated with breech presentation at delivery. We conducted a nationwide, retrospective population-based record linkage study and analyzed all singleton births in Finland from 1996 to 2016 using the mandatory health register data collected by the Finnish Institute for Health and Welfare. We compared all major congenital anomalies detected during pregnancy, birth, or the first year of life according to the fetus's presentation at the time of delivery using X -square statistic and Student's t test. We adjusted the results for known risk factors for congenital anomalies to estimate adjusted odds ratios and 95% confidence intervals. Fetuses in breech presentation at delivery had an increased risk for congenital anomalies (6.5%) compared with fetuses in cephalic presentation (3.6%), P < .001. Breech presentation was associated with nearly all types of examined congenital anomalies. The strongest associations were observed with congenital deformities of the hip, the central nervous system, the respiratory system, and the musculoskeletal system. Our study supports the theory that breech presentation is, in many cases, a symptom of a fundamental problem in fetal morphogenesis or function. Neonates born in the breech presentation have a higher risk of congenital anomalies and should undergo a postnatal screening.