1. Pinkowish, Mary MPH

Article Content

According to this study:


* In the later stages of pregnancy, clinical examination is not sufficiently sensitive to assess fetal presentation.


* Ultrasonography late in pregnancy should be mandatory in overweight or obese women.


* A cost-effectiveness analysis is necessary before routine ultrasonography in late pregnancy can be recommended for all women.



The detection of a noncephalic presentation before labor affords women and clinicians time to consider options, including external cephalic version and cesarean section. But clinical examination, which consists of abdominal palpation, can be inadequate.


A cross-sectional study was conducted among 1,633 women with singleton pregnancies who attended an antenatal clinic at a tertiary-care obstetric hospital between September 2003 and December 2004. Each participant had a clinical examination between the 35th and 37th weeks of pregnancy to assess and ultrasonography to confirm the type of fetal presentation. The investigators then used that information to calculate the sensitivity and specificity (the extent of correct diagnosis) and positive and negative predictive values of the clinical examination.


The average age of subjects was 31 years; 55% of them were nulliparous, 31% were overweight or obese, and 61% were white. Clinical examinations were conducted by an obstetrician (17%), midwife (28%), or resident or registrar (chief of staff; 55%). Ultrasonography identified 130 noncephalic presentations (8% of participants), of which 103 (6.3% of all presentations) were breech presentations and 27 (1.7%) were transverse or oblique lies. The clinical examination exhibited a sensitivity of 70% and a specificity of 95% for noncephalic presentation. For breech presentation alone, the clinical examination had a sensitivity of 70%, a positive predictive value of 55%, and a negative predictive value of 97%. The data suggest that clinical examination was increasingly more sensitive for noncephalic presentation among women who were multiparous or who had a lower body mass index (BMI). Similarly, the specificity of the clinical examination was statistically significantly greater for cephalic presentation with greater gestational age and lower BMI.


According to the authors, their findings suggest that in a general maternity population of 1,000 women in the late stage of pregnancy, clinical examination would identify noncephalic presentation in 101 women, but the diagnosis would be correct in only 56 and, further, it would be missed in 24.


The investigators conclude that routine ultrasonography in late pregnancy would improve the detection of noncephalic presentation. They add, however, that the cost, availability, and feasibility of the approach should be studied further. They also express concern that clinicians' examination skills might deteriorate if ultrasonography became routine in late pregnancy, but they believe that its use in overweight or obese women is warranted during that time.




Nassar N, et al. BMJ 2006;333(7568):578-80.