Antepartum identification of breech presentation

To determine the accuracy of clinical identification of breech presentation during third-trimester prenatal care and to evaluate factors associated with the accuracy of this determination.

Three hundred eleven patients in the third trimester were prospectively studied. Clinical determination of fetal presentation was made, after which ultrasound was used to determine the true presentation. Amniotic fluid volume, maternal abdominal wall thickness and body mass index were determined for each patient.

Among the 311 patients, there were 49 with breech presentation. Twenty-eight of 49 were identified correctly (57.1%). Multiple regression analysis indicated that gestational age, body mass index and maternal abdominal skin thickness did not influence the incidence of correct assessments. There was a significant difference between examiners in the accuracy of clinical assessment of fetal presentation.

The accuracy of assessment of breech presentation does not appear to depend on gestational age or maternal body mass index but depends more on the individual obstetric care provider.