For proper management it is vital to detect noncephalic presentations—which include breech presentation and transverse or oblique lie—in late pregnancy. A decision then can be made on whether to attempt external cephalic version at 37 weeks’ gestation. This cross-sectional analytic study, conducted at the antenatal clinic of a tertiary obstetric hospital, compared the results of clinical examination and ultrasonography in 1633 women having singleton pregnancies at 35–37 weeks’ gestation. More than 60 caregivers took part in the study; 55% of examinations were done by residents or registrars, 28% by midwives, and 17% by obstetricians.
Women participating in the study had an average age of 31 years. More than half (55%) were nulliparous, and nearly one-third (31%) were obese or overweight. Ultrasonography detected noncephalic presentation in 8% of the women examined. There were 103 breech presentations and 27 transverse or oblique lies. Clinical examination was 70% sensitive and 95% specific for identifying any type of noncephalic presentation. Similar figures were obtained for breech presentation. The positive and negative predictive values of clinical examination were 55% and 97%, respectively. Clinical examination was relatively sensitive in multiparous women and those with lower body mass indices. The specificity of clinical examination increased significantly as gestational age increased and as body mass index decreased.
Although cost analysis would be necessary before performing ultrasonography routinely to establish fetal presentation in late pregnancy, this would seem to be appropriate for obese and overweight women. All providers of pregnancy care would be expected to perform more accurately if given access to regular auditing and feedback.