全部

1·Conclusion The twin pregnancy and singleton pregnancy have different growth patterns in the third trimester pregnancy.

结论 双胎妊娠胎儿与单胎妊娠胎儿在晚孕期有着不同的生长发育规律。

2·The biological mechanism by which preterm delivery occurs might be different in twin and singleton pregnancy, and this hypothesis merits further study.

双胞胎的早产生物机转可能与单胞胎的不同，且这项假说值得之后的研究。

3·Results Twin pregnancy had more complications than singleton during in labor and puerperuim Conclusions Antenatal care should be enhanced in twin pregnancy.

结果双胎妊娠妊娠期、产时和产后并发症多于单胎妊娠，胎位是决定分娩方式的主要因素。

4·Methods Body wight index (BWI) was calculated before pregnancy and maternal weight gain and pregnancy outcomes were followed up in 2 584 primipara with singleton births.

方法对2 584例单胎初产妇，测量孕前身高、体重和孕期体重增加情况，计算体重指数（BWI），并随访妊娠结局。

5·Conclusion Caesarean section for first live birth is associated with a 47% increased risk of placenta praevia and 40% increased risk of placental abruption in second pregnancy with a singleton.

结论：首次分娩采用剖宫产女性在第二次怀孕(单胎)发生前置胎盘风险为47%，发生胎盘早剥风险为40%。