Only 2nd birth :;35 weeks 17% 48 20 42% 0.49 11 21 % 0.84
Only 1 st birth :;35 weeks Para 3+: 11 % 5% 0.18
All :;35 weeks 45% 12 44% 0.56
Other sequences of :;35 weeks 12% 123 17 14% 0.78 aRecurrence rate is derived from the Parkland obstetrical population for 1988-201n1 prior to introduction of 17-0HP-C.
bp values are one-sided.
Reproduced with permission from Nelson, 2017.
a local compounding pharmacy provided 250-mg, single-dose From the foregoing studies, evidence to support the use of vials of 17-0HP-C in sesame oil at a cost of $25 per dose. 17-0HP-C to prevent recurrent preterm birth is problematic Nelson and colleagues (2017) recently reported their indings (Young, 2017). he mechanism of action remains unknown, from this program in a prospective study of 430 women given and the pharmacological properties have yet to be established. compounded 17-0HP-C. Use of 17-0HP-C was inefective Evidence of clinical efectiveness has yet to be replicated. A confor prevention of recurrent preterm birth at 35 weeks or less dition of the FDA approval for 17-0HP-C was that a conircompared with a historical cohort from Parkland. As shown matory multicenter, double-blind randomized controlled trial in Table 42-6, 17-0HP-C did not signiicantly reduce the be conducted with a preferred primary end point of delivery rates of recurrent preterm birth regardless of prior preterm <35 weeks. This international trial-PRO LONG-is currently birth number or sequence. Moreover, plasma concentrations of underway with scheduled completion in 2018 and with an esti17-0HP-C were not diferent at 24 weeks or 32 weeks between mated enrollment of 1707 participants (PROLONG, 2014). women delivered :;35 weeks and those delivered later. Interestingly, levels were consistent with those previously reported using castor oil as a vehicle (Caritis, 2014). Last, the gestational age interval at which preterm birth recurred did not difer after use of 17-0HP-C. A side efect of 17-0HP-C was a signifiThree randomized trials are at the center of whether progestocant increase in the rate of gestational diabetes. Taken together, gen therapy should be used in women without prior preterm 17 -0 HP -C use was inefective to prevent recurrent preterm births. hese trials, shown in Table 42-7, hinge on sonographbirth and was associated with a significant side efect. ically determined cervical length. In the irst trial, Fonseca and
TABLE 42-7. Randomized Trials of Progestogen Compounds Given Prophylactically to Prevent Preterm Labor
Fonseca (2007) n = 250; 5% nulliparous, 10% <15 mm Progesterone, 200-mg Delivery <34 weeks: twins, 15% prior PTB; 8 hospitals: vaginal capsules daily 19% vs 34%, P = .02
UK, Greece, Brazil, Chile
Hassan (201l) n = 465; singletons only; 55% 10-20 mm Progesterone, 90-mg Delivery <33 weeks: 9% nulliparous; 13% prior PTB; vaginal gel daily vs 16%, p = .02