The American College of Obstetricians and Gynecologists (ACOG) has issued a report (Practice Pattern No. 6, 1997) on the management of women with post-term pregnancy. The report includes discussions on the etiologic factors, assessment of gestational age, antenatal monitoring, the role of prostaglandin gel in labor induction, and cost-effectiveness of management strategies. The following information has been excerpted from the report.

The estimated date of delivery should be determined early in a pregnancy. Consistency between historical and physical data is important in determining a reliable date. Determining accurate dates can be difficult if the patient cannot remember the last menstrual date accurately and because the proliferative phase of the cycle can vary. When post-term pregnancy exists, the cause is usually not known.

According to ACOG, antenatal surveillance of post-term pregnancies should be started by 42 weeks of gestation even though there is no evidence that monitoring improves outcomes. None of the studies that were evaluated by ACOG included post-term patients who were not monitored. No single antenatal surveillance protocol for monitoring of fetal well-being in a post-term pregnancy was found to be better than another. ACOG determined that, generally, patients receive monitoring with some combination of ultrasonography, cervical examination and nonstress testing.

The report notes that it is unknown whether induction or expectant management is preferable to manage an otherwise uncomplicated post-term patient with a favorable cervix. Evidence does indicate that induction or expectant management will result in good outcomes in post-term patients with unfavorable cervixes and without additional complications.

Most studies show that prostaglandin gel can be used safely in post-term pregnancies to promote cervical changes and induce labor. There does not appear to be a standardized dose.

ACOG reports that the cost-effectiveness of one strategy over another has yet to be determined and, therefore, no recommendation can be made.

For more information on ACOG educational bulletins, committee opinions, technical bulletins and practice patterns, contact ACOG at 409 12th St., S.W., Washington, D.C. 20090-6920; telephone: 800-762-2264.