Briscoe Donald, Nguyen Hayley, Mencer Melanie, Gautam Neeta, Kalb Daniel B
CHRISTUS St. Joseph Hospital Family Practice Residency, Houston, Texas 77002, USA.
Am Fam Physician. 2005 May 15;71(10):1935-41.
A post-term or prolonged pregnancy is one that reaches 42 weeks' gestation; approximately 5 to 10 percent of pregnancies are post-term. Studies have shown a reduction in the number of pregnancies considered post-term when early ultrasound dating is performed. Maternal and fetal risks increase with gestational age, but the management of otherwise low-risk prolonged pregnancies is controversial. Antenatal surveillance with fetal kick counts, nonstress testing, amniotic fluid index measurement, and biophysical profiles is used, although no data show that monitoring improves outcomes. Studies show a reduction in the rate of cesarean deliveries and possibly in neonatal mortality with a policy of routine labor induction at 41 weeks' gestation.
过期妊娠是指妊娠达到42周；约5%至10%的妊娠为过期妊娠。研究表明，早期超声确定孕周后，被认为是过期妊娠的数量有所减少。孕产妇和胎儿风险随孕周增加，但对于其他方面为低风险的过期妊娠的管理存在争议。采用胎动计数、无应激试验、羊水指数测量和生物物理评分进行产前监测，尽管没有数据表明监测能改善结局。研究表明，在妊娠41周时采用常规引产政策可降低剖宫产率，并可能降低新生儿死亡率。
