Intrapartum prediction of macrosomia: accuracy of abdominal circumference estimation.

OBJECTIVE

To evaluate the accuracy of abdominal circumference (AC) estimation of macrosomia early in labor and whether a cutoff value could be detected.

DESIGN

A prospective clinical trial.

SETTING

The Department of Obstetrics and Gynecology, Cairo University.

PARTICIPANTS

One hundred pregnant females presenting in early labor with clinical impression of macrosomia were examined by ultrasound, and those babies with abdominal circumference more or equal to 35 cm were recruited for the study.

INTERVENTIONS

Every woman was considered as her own control, and fetal weight was calculated using the formula of Shepard et al. The accuracy of abdominal circumference in prediction of macrosomia was evaluated using the Receiver operating characteristic curve.

RESULTS

A cutoff value of AC > or =37 cm was found to have a sensitivity of 77%, a specificity of 75%, a positive likelihood ratio of 3.1 and a negative likelihood ratio of 0.3.

CONCLUSION

Intrapartum ultrasonographic evaluation of abdominal circumference for suspected macrosomic babies in early labor is an easy, practical method that should be adopted in decision making.