探讨国家全面两孩政策实施后，生育第2个孩子产妇的临床特点，以分析其可能的生育风险。

选择2016年11月至2017年6月，在成都市妇女儿童中心医院等10家医院分娩的4 000例产妇为研究对象。将符合全面两孩政策，并且此次为生育第2个孩子的2 000例产妇纳入研究组；将同期同家医院分娩，除研究组纳入标准之外的2 000例其他产妇纳入对照组。采取调查员问询产妇及抄录病历资料的方式，收集产妇及配偶基本情况，以及本次妊娠及分娩情况，并采用χ²检验，对2组的这些临床资料进行统计学比较。本研究符合2013年修订的《世界医学协会赫尔辛基宣言》，与所有受试者签署知情同意书。

① 2组产妇年龄构成比(<30岁，≥30～35岁、≥35～40岁、≥40岁)，产妇家庭职业情况构成比(夫妇双方至少一方在国家行政机关和企业、事业单位，在非国家行政机关和企业、事业单位，其他)及家庭人均年收入构成比(≤10 000元、>10 000～50 000元、>50 000～100 000元、>100 000元)比较，差异均有统计学意义(χ²＝53.325、89.160、21.948，均为P<0.001)。具体为：研究组中产妇年龄≥30岁者，在非国家行政机关和企业、事业单位工作及家庭人均年收入>100 000元所占比例(68.2%、78.5%、46.7%)均高于对照组(58.0%、72.0%、40.2%)。2组产妇家庭户籍所在地及产妇文化程度构成比比较，差异均无统计学意义(P>0.05)。②研究组高龄(≥35岁)及剖宫产术分娩史产妇比例(23.7%、56.0%)，以及合并妊娠期高血压疾病、妊娠期糖尿病、前置胎盘产妇比例及产后出血发生率(2.3%、16.7%、3.4%、3.9%)均高于对照组(20.7%、5.4%、0.6%、14.4%、2.1%、2.0%)，并且差异均有统计学意义(χ²＝5.221，P＝0.022；χ²＝1 351.204，P<0.001；χ²＝22.443，P<0.001；χ²＝4.042，P＝0.044；χ²＝6.946，P＝0.009；χ²＝12.609，P<0.001)。2组产妇孕期贫血、胎盘植入、子宫破裂、胎膜早破及盆腔黏连发生率比较，差异均无统计学意义(P>0.05)。

孕妇高龄(≥35岁)及剖宫产术分娩史，以及合并妊娠期高血压疾病、妊娠期糖尿病、前置胎盘及产后出血等因素，可能为国家全面两孩政策实施后生育第2个孩子产妇的生育风险因素。

To explore possible reproductive risks by analyzing the clinical characteristics of puerperae having the second child after the implementation of the Universal Two-Child Policy in China.

A total of 4 000 puerperae who delivered in Chengdu Women′s & Children′s Central Hospital and other 9 hospitals were recruited. And 2 000 puerperae who consistent with the Universal Two-Child Policy and having the second child were allocated to the study group. The other 2 000 puerperae who were except for the inclusion criteria of study group and delivered in the same period and in the same hospital were allocated to the control group. The data of all subjects and their spouses′ basic situation, the pregnancy and childbirth conditions were collected through enquiring puerperae and transcribing medical records. These general clinical data were statistically compared between two groups by chi-square test. This study was consistent with the World Medical Association Declaration of Helsinki revised in 2013. All subjects in this study signed the informed consents of clinical research.

①There were significant differences between two groups in constituent ratios of maternal age (<30 years old, ≥30-35 years old, ≥35-40 years old, ≥40 years old), maternal family career situation (at least one of the spouses work in state administrative organs or enterprises and institutions, work in non-state administrative organs or enterprises and institutions, others) and per capita family annual income (≤10 000 yuan, >10 000-50 000 yuan, >50 000-100 000 yuan, >100 000 yuan) (χ²=53.325, 89.160, 21.948; all P<0.001). Specific for proportions of maternal age≥30 years old, work in non-state administrative organs or enterprises and institutions and per capita family annual income≥100 000 yuan of study group (68.2%, 78.5%, 46.7%) were all higher than those of control group (58.0%, 72.0%, 40.2%). There were no significant differences between two groups in constituent ratios of household domicile and the degree of maternal culture (P>0.05). ②The proportions of maternal age≥35 years old and the cesarean section history (23.7%, 56.0%), and the incidence rates of hypertension disorders complicating pregnancy, gestational diabetes mellitus, placenta previa and postpartum hemorrhage in study group (2.3%, 16.7%, 3.4%, 3.9%) were all higher than those in control group (20.7%, 5.4%, 0.6%, 14.4%, 2.1%, 2.0%), and the differences were statistically significant (χ²=5.221, P=0.022; χ²=1 351.204, P<0.001; χ²=22.443, P<0.001; χ²=4.042, P=0.044; χ²=6.946, P=0.009; χ²=12.609, P<0.001). There were no significant differences between two groups in the incidence rates of pregnancy anemia, placenta implantation, uterine rupture, premature rupture of membrane and pelvic adhesions (P>0.05).

Maternal age≥35 years old and cesarean section history, as well as hypertension disorders complicating pregnancy, gestational diabetes mellitus, placenta previa and postpartum hemorrhage, may be the reproductive risk factors of women who consistent with the Universal Two-Child Policy and having the second child.