基于胎盘病理性炎症的<34孕周早产危险因素分析

目的 基于胎盘病理性炎症，探讨<34孕周早产的危险因素。方法 以2008年1月至2010年10月在上海交通大学附属国际和平妇幼保健院孕27+0～33+6周住院并分娩的孕产妇为研究对象。将研究对象分为孕27+0～31+6周和孕32+0～33+6周组，探讨<34孕周早产的危险因素。结果 ①孕27+0～31+6周组和孕32+0～33+6周组分别纳入106和110例，两组在母亲年龄、剖宫产和产前使用激素方面差异均无统计学意义。48.1%（104/216）胎盘病理性炎症反应阳性（MIR+），其中51.0%（53/104）为仅母体炎症反应阳性（MIR+FIR-），49.0%（51/104）母体-胎儿炎症反应均阳性（MIR+FIR+）；51.9％（112/216）母体-胎儿炎症反应均阴性(MIR-FIR-)，未见母体炎症阴性-胎儿炎症阳性（MIR-FIR+）的病理结果。②早产主要危险因素包括早产胎膜早破（n=105）、临产(n=115)、妊娠高血压(n=52)、胎儿宫内窘迫(n=51)、产前出血(n=47)、前置胎盘(n=21)、流产史(n=108)、非正规产检(n=46)、妊娠合并内科疾病(n=23)和宫内生长迟缓(n=10)等。③在孕27+0～31+6周组中，MIR+FIR-亚组和MIR+FIR+亚组早产胎膜早破以及临产发生率显著高于MIR-FIR-亚组（64.3% 、83.9% vs 21.3%，P=0.000；78.6%、67.7% vs 46.8%，P=0.016）；母亲妊娠高血压发生率显著低于MIR-FIR-亚组(0、6.5% vs 40.4%，P=0.000)；MIR+FIR+亚组产前出血的发生率显著低于MIR-FIR-和MIR+FIR-亚组（6.5% vs 29.8%，32.1％，P=0.027）。在孕32+0～33+6周组中，MIR+FIR-亚组和MIR+FIR+亚组早产胎膜早破、临产发生率显著高于MIR-FIR-亚组(52.0%、90.0% vs 30.8%，P=0.000)。④当MIR-FIR-时，孕27+0～31+6周组临产发生率显著高于孕32+0～33+6周组（46.8%和20.0%，P=0.003）。当MIR+FIR-和MIR+FIR+时，各胎龄组间危险因素差异均无统计学意义。结论 宫内炎症阳性时多为自发性早产，合并早产的其他危险因素较少；宫内炎症阴性时多存在多样的医源性早产因素。宫内炎症存在时并不增加胎儿宫内窘迫、胎盘早剥发生率。

Risk factors for preterm birth less than 34 weeks gestation based on placental histopathology

Objective To identify risk factors for preterm birth less than 34 weeks gestation based on placental histopathology. Methods Clinical characteristics and placental histological results were collected from 216 singleton pregnancies. According to gestational ages, the subjects were divided into 2 groups, group 1 with 27+0～31+6 weeks gestation group (n=106) and group 2 with 32+0～33+6 weeks gestation group (n=110). Results There was no difference in maternal age, cesarean section and antenatal steroid between two groups. The placental histopathological results showed that intrauterine inflammation response was present in 104 of 216 cases (48.1%), and of 104 cases, in 53 cases (51.0%) the inflammation involved maternal side only （MIR+FIR-）and in 51 cases (49.0%) the inflammation involved both maternal and fetal sides（MIR+FIR+）. There was no case with fetal inflammation response only（MIR-FIR+）. The risk factors included premature preterm rupture of membranes (n=105), labor (n=115), hypertensive disorders in pregnancy(n=52), fetal distress (n=51), antepartum hemorrhage(n=47), placentaprevia(n=21), history of abortion(n=108) , irregular antenatal attendance(n=46), medical disorders(n=23) and intrauterine growth retardation(n=10) and so on. In the 27+0-31+6 weeks gestation group, MIR+FIR- or MIR+FIR+ was more frequently associated with premature preterm rupture of membranes and labor compared with MIR-FIR-（64.3%, 83.9% vs 21.3%，P=0.000；78.6%, 67.7% vs 46.8%，P=0.016）, and less frequently associated with hypertensive disorders in pregnancy compared with MIR-FIR- (0, 6.5% vs 40.4%，P=0.000); MIR+FIR+ was less frequently associated with antepartum hemorrhage compared with MIR-FIR- or MIR+FIR-（6.5% vs 29.8%,32.1%，P=0.027）. In the 32+0-33+6 weeks gestation group, MIR+FIR- or MIR+FIR+ was more frequently associated with premature preterm rupture of membranes compared with MIR-FIR-（52.0%, 90.0% vs 30.8%，P=0.000）. Under the condition of MIR-, the risk factors were similar between 27+0-31+6 weeks and 32+0-33+6 weeks gestation groups except for labor （46.8% vs 20.0%，P=0.003）, and under the condition of MIR+, the risk factors were similar between two groups. Conclusions Under the condition of intrauterine inflammation response positive, the preterm delivery is mostly spontaneous. However, under the condition of intrauterine inflammation response negative, the preterm delivery mostly indicates to be with various risk factors. The intrauterine inflammation response does not increase the risk of fetal distress and placental abruption.