The manufacturers recommend caution when these preparations are used in women with ruptured membranes. This concern is also extended to women with glaucoma or asthma. However, in a review of 189 women with asthma, dinoprostone was not associated with asthma worsening or exacerbation (Towers, 2004). Other contraindications listed by the manufacturers include a history of dinoprostone hypersensitivity, suspicion of fetal compromise or cephalopelvic disproportion, unexplained vaginal bleeding, women already receiving oxytocin, those with six or more previous term pregnancies, those with a contraindication to vaginal delivery, or women with a contraindication to oxytocin or who may be endangered by prolonged uterine contractions, for example, those with a history of cesarean delivery or uterine surgery.
Administration. PGE2 preparations should only be administered in or near the delivery suite. Moreover, uterine activity and fetal heart rate should be monitored (American College of Obstetricians and Gynecologists, 2016). These guidelines stem from the risk of uterine tachysystole. When contractions begin, they are usually apparent in the irst hour and show peak activity in the irst 4 hours. According to manufacturer guidelines, oxytocin induction that follows prostaglandin use for cervical ripening should be delayed for 6 to 12 hours following PGE2 gel administration or for at least 30 minutes after removal of the vaginal insert.
Prostaglandin E,
Misoprostol-Cytotec-is a synthetic prostaglandin EI (PGE1) that is approved as a 100-or 200-�g tablet for peptic ulcer prevention. It has been used "of label" for preinduction cervical ripening and may be administered orally or vaginally. he tablets are stable at room temperature. Although widespread, the of-label use of misoprostol has been controversial (Wagner, 2005; Weeks, 2005). Specifically, G. D. Searle & Company notiied physicians that misoprostol is not approved for labor induction or abortion (Cullen, 2000). Still, the American College of Obstetricians and Gynecologists (2016) reairmed its recommendation for use of the drug because of proven safety and eicacy. It currently is the preferred prostaglandin for cervical ripening at Parkland Hospital. In one review of 234 women administered misoprostol, no instances of asthma exacerbation were associated with its use, and the risk of this was calculated to be <2 percent (Rooney Thompson, 2015).
Vaginal Administration. Compared with intracervical or intravaginal PGE2, vaginally administered misoprostol tablets ofer equivalent or superior eicacy for cervical ripening or labor induction. A metaanalysis of 121 trials also conirmed these indings (Hofmeyr, 2010). Compared with oxytocin or with intravaginal or intracervical dinoprostone, vaginal misoprostol increased the vaginal delivery rate within 24 hours. In this review, although the uterine tachysystole rate rose, this did not afect cesarean delivery rates. Moreover, compared with dinoprostone, misoprostollowered the need for oxytocin induction,
Induction and Augmentation of Labor 507 but it increased the frequency of meconium-stained amni onic fluid. Higher doses of misoprostol are associated with a decreased need for oxytocin but with more uterine tachysystole, with and without fetal heart rate changes. The American Col lege of Obstetricians and Gynecologists (2016) recommends a 25-�g vaginal dose-a fourth of a 1 OO-�g tablet. he drug is evenly distributed among these quartered tablets.