目的综合评价三胎和单胎妊娠的分娩孕周、新生儿出生体重及死亡率。方法对满足条件的7篇有关三胎妊娠与单胎妊娠的分娩孕周、新生儿出生体重及死亡率的回顾性研究进行Meta分析。结果三胎妊娠的平均分娩孕周比单胎的平均分娩孕周提前6.24周,95%可信区间(95%CI)-6.54～-5.94。三胎妊娠的新生儿平均出生体重比足月单胎低1.51kg,95%CI-1.59～-1.44。三胎妊娠新生儿死亡的危险性是单胎的10.50倍(OR=10.50,95%CI10.07～10.95)。结论三胎妊娠与单胎妊娠相比,平均分娩孕周缩短、新生儿平均出生体重明显低于单胎;其新生儿死亡率明显高于单胎。 Objective To evaluate the birth gestational age, newborn birth weight and mortality in third and single pregnancy. Methods Meta-analysis was performed on seven retrospective studies of gestational age, newborn birth weight and mortality that met the criteria of 7 gestational and singleton pregnancies. Results The mean gestational age of third trimester was 6.24 weeks ahead of the average gestational age of single childbirth, 95% confidence interval (-6.54 ~ -5.94). The average birth weight of newborns with triple pregnancy was 1.51kg lower than that of term singletons, 95% CI-1.59 ~ -1.44. The risk of neonatal death in triple pregnancy was 10.50 times singleton (OR = 10.50, 95% CI 10.07 to 10.95). Conclusion Compared with singleton pregnancies, the average gestational age of the third trimester pregnancy is shortened and the average birth weight of newborns is significantly lower than that of singletons. The neonatal mortality rate is significantly higher than that of singletons.