title: Can breech presentation at birth be predicted from ultrasound examinations during the second or third trimesters?
abstract: OBJECTIVE
  To determine at which gestational age the ultrasound finding of a breech presentation should compel us to follow the pregnancy more closely with repeat ultrasound examinations.
  
  
  METHODS
  A retrospective longitudinal investigation of ultrasound examinations in the second and third trimesters is reported. The study group consisted of 157 breech deliveries and a control group of 1325 vertex deliveries.
  
  
  RESULTS
  In the study population (breech delivery) 63.2% were presenting as breech during the 15th-19th weeks of pregnancy--almost the same percentage as in the vertex-born group (of which 55.2% were breech presentation). In the interval between 20 and 24 weeks the same relationship was observed (50.8% and 42.9%, respectively). From 25 weeks until delivery 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 with 28.9% in the vertex-born group (P < 0.0001). That difference increased as the pregnancy progressed.
  
  
  CONCLUSIONS
  Patients found sonographically to be a breech presentation at 25 weeks' gestation or later are at high risk for malpresentation at delivery.
authors: Department of Obstetrics and Gynecology, Shaare Zedek Medical Center, Jerusalem, Israel.
authors: O P
authors: OP
authors: Tadmor
authors: R
authors: R
authors: Rabinowitz
authors: L
authors: L
authors: Alon
authors: V
authors: V
authors: Mostoslavsky
authors: Y
authors: Y
authors: Aboulafia
authors: Y Z
authors: YZ
authors: Diamant
mesh_terms: D000328:Adult; D001946:Breech Presentation; D005260:Female; D005865:Gestational Age; D006801:Humans; D008137:Longitudinal Studies; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D012189:Retrospective Studies; D012307:Risk Factors; D016216:Ultrasonography, Prenatal / Q000379:methods*