Can breech presentation at birth be predicted from ultrasound examinations during the second or third trimesters?
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.
Tadmor
O P
OP
Department of Obstetrics and Gynecology, Shaare Zedek Medical Center, Jerusalem, Israel.
Rabinowitz
R
R
Alon
L
L
Mostoslavsky
V
V
Aboulafia
Y
Y
Diamant
Y Z
YZ
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*