Objectives To compare between the effectiveness and safety of two different daily doses of vaginal progesterone (400 vs. 200 mg) in the prevention of preterm labor in twin pregnancy. Methods This is a prospective single-blinded randomized controlled trial conducted on 100 primi-gravida who had twin pregnancy and attended the antenatal clinic of a University hospital. They were equally and randomly allocated into two arms each containing 50 patients. Arm 1 received 400 mg and arm 2 received 200 mg vaginal progesterone daily at bed time starting from 14 weeks of pregnancy to 36 weeks. Transvaginal ultrasound was performed for assessment of the length of cervix at 14 and 22 weeks. Results Both arms of the current study were comparable regarding the cervical length at 14 and 22 weeks, mean gestational age at delivery, incidence of pre-term delivery, birth weight of the first twin. Second twin in addition to the average weight of both twins. No statistical significance differences between two arms regarding incidence of early neonatal death. NICU, mechanical ventilation, length of admission in NICU for the first twin. Second twin as well as both twins. Conclusions Vaginal progesterone treatment with different doses was tolerable, but wasn’t effective in the prevention of preterm labor in twin pregnancy.

中文翻译：

---

两剂阴道黄体酮 400 与 200 毫克预防双胎早产的随机对照试验

目的 比较两种不同日剂量阴道黄体酮（400 与 200 毫克）预防双胎妊娠早产的有效性和安全性。方法 这是一项前瞻性单盲随机对照试验，对 100 名双胎妊娠并就读于大学医院产前门诊的初产妇进行。他们被平等地随机分配到两个组中，每个组包含 50 名患者。从怀孕 14 周到 36 周，第 1 组每天在睡前接受 400 毫克，第 2 组每天接受 200 毫克阴道黄体酮。在 14 周和 22 周时进行经阴道超声评估宫颈长度。结果 本研究的两组在 14 周和 22 周时的宫颈长度、分娩时的平均胎龄、早产发生率、第一个双胞胎的出生体重。第二个双胞胎除了两个双胞胎的平均体重。在新生儿早期死亡的发生率方面，两组之间没有统计学上的显着差异。NICU，机械通气，第一个双胞胎在 NICU 的住院时间。第二个双胞胎以及两个双胞胎。结论不同剂量的阴道黄体酮治疗可耐受，但对双胎妊娠早产的预防效果不佳。