A randomized prospective trial of the obstetric forceps versus the M-cup vacuum extractor.

Publication/Presentation Date

11-1-1996

Abstract

OBJECTIVE: Our purpose was to determine the efficacy of the obstetric forceps versus the M-cup, a new vacuum extractor cup, and maternal-neonatal complication rates.

STUDY DESIGN: Over a 10-month period operative vaginal deliveries were randomized between the obstetric forceps and the M-cup vacuum extractor cup. Maternal demographics, indication for intervention, analgesia, position, station, degree of asynclitism, fetal caput-molding, and time from application to delivery were prospectively recorded. Episiotomy and extensions, lacerations, and the reason for abandonment of the randomized instrument were noted in both groups. Fetal weight, Apgar scores, cord arterial gases, hyperbilirubinemia, phototherapy, and any evidence of fetal trauma were documented at delivery or in the nursery.

RESULTS: Six hundred thirty-seven women were randomized, 315 in the forceps group and 322 in the M-cup group. There were no differences in maternal demographic variables. The station, position, degree of asynclitism, or requirement for rotation was not different between the groups. The corrected efficacy rates were forceps 92% and M-cup 94% (p = 0.217). The M-cup deliveries were accomplished more rapidly than forceps deliveries (p < 0.001) and were associated with a lower rate of episiotomy (p < 0.001), third-degree (p < 0.001) and fourth-degree (p = 0.002) lacerations, but blood loss as clinically estimated (p = 0.232) or as measured by hemoglobin levels (p = 0.166) was not significantly different. Forceps deliveries were associated with fewer clinically diagnosed cephalhematomas (p = 0.015) than M-cup deliveries were, but there were no differences in the number of neonates diagnosed with hyperbilirubinemia (p = 0.377) or in the number of infants treated with phototherapy (p = 0.660).

CONCLUSIONS: The M-cup vacuum extractor cup appears to be as efficient (and faster) than the obstetric forceps but is associated with significantly more fetal cephalhematomas, whereas maternal injuries are more common with the forceps.

Volume

175

Issue

5

First Page

1325

Last Page

1330

ISSN

0002-9378

Disciplines

Medicine and Health Sciences

PubMedID

8942509

Department(s)

Department of Obstetrics and Gynecology

Document Type

Article

Share

COinS