CAN BREECH PRESENTATION AT BIRTH BE PREDICTED FROM ULTRASOUND EXAMINATIONS DURING THE 2ND OR 3RD TRIMESTERS

Objectives: To determine at which gestational age the ultrasound findi ng of a breech presentation should compel us to follow the pregnancy m ore closely with repeat ultrasound examinations. Methods: A retrospect ive longitudinal investigation of ultrasound examinations in the secon d and third trimesters is reported. The study group consisted of 157 b reech deliveries and a control group of 1325 vertex deliveries. Result s: In the study population (breech delivery) 63.2% were presenting as breech during the 15th-19th weeks of pregnancy - almost the same perce ntage as in the vertex-born group (of which 55.2% were breech presenta tion). In the interval between 20 and 24 weeks the same relationship w as observed (50.8% and 42.9%, respectively). From 25 weeks until deliv ery a statistically significant difference appeared between the breech -delivered group and the vertex-delivered group: during weeks 25-29 in the breech-delivered group, 70.6% were breech presentation compared w ith 28.9% in the vertex-born group (P < 0.0001). That difference incre ased as the pregnancy progressed. Conclusions: Patients found sonograp hically to be a breech presentation at 25 weeks' gestation or later ar e at high risk for malpresentation at delivery.