Wing and colleagues (2013) described use of a vaginal polymer insert containing 200 �g of PGE1• hey compared its eicacy with 10-mg dinoprostone inserts, and preliminary observations are favorable.
Oral Administration. PGE1 tablets are also efective when given orally. One Cochrane metaanalysis of76 trials reported that oral misoprostol compared with placebo signiicantly raised the rate of vaginal birth within 24 hours, while decreasing the need for oxytocin and lowering the cesarean delivery rate. Comparisons of oral misoprostol and oxytocin and of oral misoprostol and dinoprostone also found signiicantly reduced rates of cesarean delivery with misoprostol. Similar eicacy was noted between oral misoprostol and vaginal administration, although oral administration was associated with significantly higher Apgar scores and less postpartum hemorrhage (Alirevic, 2014). Thorbionson and associates (2017) also reported lower rates of cesarean delivery for oral misoprostol compared with vaginal dinoprostone.
stimulate nitric oxide (NO) production locally (Chanrachakul, 2000). First, NO is likely a mediator of cervical ripening. Also, cervical NO metabolite concentrations are increased at the beginning of uterine contractions. And, cervical NO produc tion is very low in postterm pregnancy (Vaisanen-T ommiska, 2003, 2004).
Bullarbo and colleagues (2007) reviewed rationale and use of two NO donors, isosorbide mononitrate and gyceyl trinitrate. Isosorbide mononitrate induces cervical cyclooxygenase 2 (COX-2), and it also initiates cervical ultrastructure rearrangement similar to that seen with spontaneous cervical ripening (Ekerhovd, 2002, 2003). Despite this, NO donors are less efective clinically than prostaglandins, either PGE2 or misoprostol, for cervical ripening. In one large metaanalysis, the rate of cesarean delivery was not reduced in those given NO donors compared with those given placebo, intravaginal or intracervical prostaglandins, intravaginal misoprostol, or intracervical catheter (Ghosh, 2016). However, NO donors were associated with signiicantly more headaches, nausea, and vomiting.
These include transcervical placement of a Foley catheter, with or without extraamnionic saline infusion; hygroscopic cervical dilators; and membrane stripping. In their metaanalysis, Jozwiak and associates (2012) reported that mechanical techniques reduced the risk of uterine tachysystole compared with prostaglandins, although cesarean delivery rates were unchanged. Trials comparing mechanical techniques with oxytocin found a lower rate of cesarean delivery with mechanical methods. Trials comparing mechanical techniques with dinoprostone found a higher rate of multiparas undelivered at 24 hours with mechanical techniques. In another metaanalysis comparing Foley catheter placement with intravaginal dinoprostone inserts, rates of cesarean delivery were similar, but uterine tachysystole was less frequent with catheter use Qozwiak, 2013).