oxytocin and Vaginal-Fistula

Observations of the effects of oxytocics on the human pregnant cervix have been made in vivo using a double open ended catheter technique. Prostaglandin E, prostaglandin F2alpha and oxytocin had similar but no specific effects upon the intracervical canal pressure; ergometrine caused contractions of the cervix. The significance of these findings is discussed in relation to cervical rupture and cervico-vaginal fistulae that have been reported following second trimester abortion induced with prostaglandins.

Topics: Abortion, Induced; Adolescent; Adult; Cervix Uteri; Ergonovine; Female; Humans; Oxytocics; Oxytocin; Pregnancy; Pregnancy Trimester, Second; Prostaglandins E; Prostaglandins F; Uterine Cervical Diseases; Uterine Contraction; Uterine Rupture; Vaginal Fistula

A rare but difficult to treat complication of midtrimester abortion is cervicovaginal fistula. It has been reported as a consequence of criminal, spontaneous, and induced abortions with either laminaria, Hegar dilatation, puncture of the ovum, or by injection of soap. This condition was recently reported as a consequence of intraamniotic hypertonic saline or prostaglandin (PG) instillation. At the Women's Hospital in Los Angeles, 5291 midtrimester abortions with intraamniotic instillation of hypertonic saline had been performed since the advent of elective abortion. There were 4 cases of central cervical rupture (cervicovaginal fistula) for a net incidence of 1:1000. 3 out of 373 intraamniotic PGF2alpha-treated patients developed cervical fistula for an incidence 10 times higher than saline abortion. Other studies confirm this finding. If all such studies are combined, the net incidence is 9 in 678 cases or 1.3%. High risk patients include those who are pregnant for the 1st time, are less than 21 years old, and are treated with hypertonic saline augmented by oxytocin. The fistula may occur with intraamniotic PGF2alpha alone, but the incidence is greater in patients receiving PGs and oxytocin together. A recurring feature is a moderate to severe cramping pain without cervical response even before oxytocin is started. The use of mechanical dilatation of the cervix with the introduction of either laminaria tents or Foley catheters is suggested for primigravid patients receiving hypertonic saline and intravenous oxytocin augmentation. If cervical spasm is the mechanism of action of PGF2alpha, initial insertion of laminaria should be considered with all primigravid patients. Further study of a larger series should be done to elucidate the role of PGs in the development of cervicovaginal fistula. 7 case reports are presented.

Topics: Abortion, Induced; Adolescent; Adult; Catheterization; Dilatation; Female; Fistula; Humans; Hypertonic Solutions; Labor, Induced; Oxytocin; Parity; Pregnancy; Prostaglandins; Sodium Chloride; Uterine Cervical Diseases; Vaginal Fistula