Utilization of real-time ultrasound on labor and delivery in an active academic teaching hospital

Ultrasound (US) is currently available on most if not all Labor and Delivery (L+D) services. Our objective was to survey utilization of real-time US on L+D in an active academic teaching hospital.

Between April 1, and July 31, 1998, all US examinations performed for clinical purposes on patients presenting to L+D, were documented. Data collected included: gestational age, whether or not the patient was in labor, number of fetuses, and indication for US. All US examinations were performed by OB/GYN housestaff at the PGY 2-3 level, and fellows in Maternal-Fetal Medicine. Statistical analysis included Student's t-test and chi2 when appropriate, with p < 0.05 considered significant throughout.

During the 4-month study period, 1316 patients delivered and 1363 were discharged from L+D, not in labor. Of 630 US examinations 31.64% (192 of 630) and 67.69% (418 of 630) were performed in laboring versus nonlaboring patients, respectively. Of all patients delivered during the study period, 14.5% (192 of 1316) underwent intrapartum US, and of all nonlaboring patients, 30.66% (418 of 1363) underwent US on L+D. The mean gestational age at the time of assessment was 37.32 +/- 4.23 weeks' versus 35.74 +/- 5.76 weeks' gestation, in laboring versus nonlaboring patients respectively, p < 0.05. Main indications for US in patients in labor were; fetal presentation in patients with spontaneous rupture of membranes (SROM) 34.4% (n = 66), confirmation of vertex presentation 20.3% (n = 39), preterm labor 12% (n = 23), multiple gestation 7.3% (n = 14), and malpresentation 7.3% (n = 14). Main indications for patients not in labor were; amniotic fluid index 15.8% (n = 66), SROM 15.6% (n = 65), postdates 9.8% (n = 41) placental location 9.6% (n = 40), and decreased fetal movement 9.3% (n = 39). Ultrasound-guided interventions included: all deliveries of multiple gestations (n = 9), version in nonlaboring patients (n = 10), and postpartum curettage for retained placental tissue in conjuction with severe early postpartum hemorrhage (n = 2). The incidences of each separate indication for US were significantly different between laboring versus nonlaboring patients, p < 0.05, respectively.

US examination is performed in 15% of patients in labor and 31% of patients not in labor assessed on L+D, constituting a widely applied diagnostic tool in this environment.