羊水粪染与孕周及新生儿酸碱平衡状态

OBJECTIVE: To estimate whether the acid-base status of neonates born to women with meconium-stained amniotic fluid varies across gestation. METHODS: We carried out a retrospective cohort study of all pregnancies that were complicated by meconium-stained amniotic fluid in 2004. Cases were identified from a perinatal pathology database that contained data on all pregnancies complicated by meconium- stained amniotic fluid. Data abstracted from the charts included gestational age at delivery, umbilical arterial pH, birth weight, and the presence or absence of labor. Cases were stratified according to gestational age at delivery. The distribution of meconium-stained amniotic fluid across gestation was computed. The mean umbilical arterial pH values (with 95% confidence intervals) across gestation were assessed by analysis of variance. RESULTS: The mean umbilical arterial pH in women with meconium-stained amniotic fluid did not differ across gestation. The overall incidence of meconium-stained amniotic fluid was 12.0% (766 of 6,403 deliveries). The rates of meconium-stained amniotic fluid increased from 1.2% at 32 weeks to 100% at 42 weeks. CONCLUSION: The rising incidence of meconium-stained amniotic fluid with gestational age is consistent with the hypothesis that fetal maturation is a major etiologic factor in meconium passage. Also, the lack of variation of mean umbilical arterial pH across gestation suggests that fetal acidemia is not increased when meconium passage occurs earlier in pregnancy rather than at later gestational ages.

胎盘早剥的危险因素:早产胎膜早破、子宫内感染和羊水过少

OBJECTIVE: To examine whether preterm premature rupture of membranes (PROM), intrauterine infection, and oligohydramnios are risk factors for placental abruption. METHODS: Data for this retrospective cohort study were derived from the 1988 National Maternal and Infant Health Survey (N=11,777). Association between abruption and these clinical risk factors was expressed as relative risk (RR) and 95%confidence interval (CI), with multivariate adjustment for potential confounders. RESULTS: The overall incidence of abruption was 0.87%. The risk of abruption was 3.58-fold higher (95%CI 1.74-7.39)among women with preterm PROM (2.29%) compared with women with intact membranes (0.86%). The rates of abruption among women with and without intrauterine infection were 4.81%and 0.83%, respectively (RR 9.71, 95%CI 3.23-29.17). However, oligohydramnios was not associated with abruption (1.46%compared with 0.87%; RR 2.09, 95%CI 0.92-5.31). Compared with women with intact membranes, the RR for abruption among preterm PROM and whose membranes were ruptured for 24-47 hours and 48 hours or more before delivery, respectively, were 2.37 (95%CI 0.99-9.09), and 9.87 (95%CI 3.57-27.82). When preterm PROM was accompanied by intrauterine infections, the RR for abruption was 9.03 (95%CI 2.80-29.15) compared with women with intact membranes and no infections. Similarly, preterm PROM accompanied by oligohydramnios conferred over a 7.17-fold risk (95%CI 1.35-38.10) for abruption compared with women with neither of these 2 conditions. CONCLUSION: Women presenting with preterm PROM are at increased risk of developing abruption, with the risk being higher either in the presence of intrauterine infections or oligohydramnios. Physicians managing patients with preterm PROM should be aware that these patients are at increased risk of developing abruption after 24 hours following preterm PROM.

前置血管的产前诊断对妊娠结局的影响

OBJECTIVE: To evaluate outcomes and predictors of neonatal survival in pregnancies complicated by vasa previa and to compare outcomes in prenatally diagnosed cases of vasa previa with those not diagnosed prenatally. METHODS: We performed a multicenter study of 155 pregnancies complicated by vasa previa. Cases were obtained from the Vasa Previa Foundation and 6 large hospitals. Comparisons were made between groups based on prenatal diagnosis status and neonatal survival. RESULTS: The overall perinatal mortality was 36%(55 of 155). In 61 cases (39%), vasa previa was diagnosed prenatally; 59 of 61 (97%) infants from these pregnancies survived compared with 41 of 94 (44%) in cases not diagnosed prenatally (P < .001). Median 1and 5-minute Apgar scores in cases diagnosed prenatally were 8 and 9, respectively, compared with 1 and 4 among survivors in cases not diagnosed prenaially (P < .001). More than half (24 of 41) of surviving neonates born to women without prenatal diagnosis required blood transfusions compared with 2 of 59 diagnosed prenatally (P < .001). Multivariable logistic regression analysis showed that the only significant predictors of neonatal survival were prenatal diagnosis (P <.001) and gestational age at delivery (P = .01). CONCLUSIONS: Good outcomes with vasa previa depend primarily on prenatal diagnosis and cesarean delivery at 35 weeks of gestation or earlier should rapture of membranes, labor, or significant Heeding occur.