肥胖和糖尿病对巨大儿发生率的影响

This study was undertaken to determi ne the relative con-tribution of abnormal pregravid maternal body habitus and diabetes on the prevalence of large -for -gestational -age infants.Maternal and neonatal reco rds for singleton term(≥37weeks’estimated gestational age)deliveries January1997through June 2001were reviewed.Subjects were characterized by pregravid body mass index(BMI ),divided into underweight (BMI <19.8kg /m 2 ),normal(BMI 19.8-25kg /m 2 ),overweight (BMI 25.1-30kg /m 2 ),and obese(BMI >30kg /m 2 )subgroups.Diabetes was classified as gestational,treated with diet alone(A1GDM),or with insulin(A2GDM),and pregestaional diabetes(PDM).Newborn weight greater than the 90t h percentile for gestational age,based on published local birth weight data,defined large for gestational age(LGA).The risk of LGA delivery for underweight,overweight,and obese women were compared with that o f women with nor-mal pregravid BMI.Multiple regression models,including parity,newborn sex,BMI,race,and d iabetes,were constructed to examine the relative effect of abnormal BMI and diabetes on the risk of the delivery of an LGA infant.Complete data for 12,950deliveries were included(1,64013.0%underweight,2,99123.7%overweight,and2,92823.2%obese).LGA delivery affected 11.8%of the study sample;303(2.3%)of subjects had A1GDM,whereas 94(0.7%)had A2GDM,and 133(1.6%)had PDM.Compared with normal BMI subjec ts,obese womenwere at elevated risk for LGA delivery(16.8%vs 10.5%;P<.0001)as were overweight women(12.3%vs 10.5%;P =.01).Diabetes was also a risk factor for LGA deliv-ery(A1GDM:29.4%vs 11.4%A2GDM:29.8%vs 11.7%;PDM:38.3%vs 11.6%;P <.0001for each).Other risk factors for LGA delivery included parity(13.2%vs 9.5%;P <.0001),and male gender(14.3%vs 9.3%;P <.0001).Black race and low pre-gravid BMI were associated with a low er risk of LGA de-livery(9.0%vs 13.7%;P <.0001)and(6.4%vs10.5%;P =.006),respectively.Multiple regressio n revealed the independent influence of pregravid obesity and PDM,increasing the risk of LGA deliv ery(BMI >30kg /m 2Adjusted odds ratio(AOR)=1.6),and PDM(AOR=4.4).Obesity and pregestational diabetes are inde-pendently associated an increased r isk of LGA delivery.The impact of abnormal body habitus o n birth weight grows as BMI increases.Diabetes has the greatest affect on the normal and underweight population.With the increasing prevalence and relative frequency o f overweight and obe-sewomen in pregnancy compared with d iabetes(46.7%vs4.1%),abnormal maternal body habitus exh ibits the strongest influence on the prevalen ce of LGA delivery in our population.

母体肥胖和体重增加对剖宫产术后阴道分娩成功率的影响

This study was undertaken to determi ne the impact of ma-ternal obesity on success of a trial of labor(vaginal birth after cesarean sectionVBAC)after a single low transverse ce-sarean delivery.Individual charts of women with low transverse cesarean delivery in their first viable pregnancy who underwent a VBAC in their second v iable pregnancy at our urban tertiary care institution were reviewed.Maternal body mass index(BMI )was classified as underweight (<19.8kg /m 2 ),normal(19.8-24.9kg /m 2 ),over-weight (25-29.9kg /m 2 ),or obese(≥30kg /m 2 ).Clinical characteristics and labor outcomes were assessed.Factors potentially affecting VBAC success were analyzed by univariate analysis.Logistic re gressions were performed to determine the impact of maternal p regravid BMI on VBAC success after controlling for c onfounding factors.Of 510women attempting a trial of labor,337(66%)were successful and 173(34%)failed VBAC.Decreased VBAC success was seen in obese(54.6%)but not over-weight (65.5%)women compared with women of normal BMI (70.5%),P =.003and.36,respectively.Un-derweight women had more VBAC success than women of normalBMI (84.7%vs 70.5%,P =.04).Controlling for other factors,the association b etween increasing pre-gravid BMI and BMI ≥30kg /m 2 with decreased VBAC success persisted,P =.03and.006,r espectively.Nor-mal BMI women who became overweight before the second pregnancy had decreased VBAC success compared with those whose BMI remained normal(56.6%vs 74.2%,P =.006).However,overweight women who decreased their BMI to normal before the second pregnancy did not significantly improve VBAC success(64.0%vs 58.4%,P =.67).Increasing pregravid BMI and weigh t gain be-tween pregnancies reduce VBAC succe ss after a single low transverse cesarean delivery.

围生期干预和新生儿存活率的关系

The purpose of this study was to evaluate trends in the level of obstetric and neonatal intervention near the limit of viability and perinatal morbidity and mortality rates over time. In this retrospective chart review, live born infants who were delivered at 23 to 26 weeks of gestation and who weighed between 500 and 1500 g between 1990 and 2001 in an urban tertiary care center were identified. Maternal charts were reviewed for clinical characteristics and antenatal and intrapartum course. Neonatal charts were reviewed for short term morbidities that included respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, retinopathy of prematurity, and survival. The study group was divided into 2 cohorts (group I:1990- 95; group II:1996- 2001); the obstetrician s willingness to intervene, neonatal resuscitation efforts, infant mortality (in gestational age subgroups) rate, and short term morbidity rate were compared. Multivariate analyses, which controlled for obstetrician willingness to intervene, neonatal resuscitation, cohort, and gestational age, were performed to evaluate infant survival in the entire cohort and for morbidity in the survivors. Records for 260 mothers and 293 newborn infants were evaluated. Comparing the 2 cohorts (group I vs II), we found increases over time in intent to intervene for fetal indication (70% vs 89% ; P =. 0007), cesarean delivery for malpresentation (20% vs 42% ; P =. 0003), and survival (54% vs 70% ; P =. 003). Pregnancies in group 1 were less likely to have received antenatal steroids (7.7% vs 60% ) or surfactant (39% vs 73% ; P <.0001 for each). Survival increased with advancing delivery gestation (24% , 51% , 68% , and 85% at 23, 24, 25, and 26 weeks of gestation, respectively; P <.0001). However, among survivors, the incidences of necrotizing enterocolitis, retinopathy of prematurity, intraventricular hemorrhage, respiratory distress syndrome, sepsis, and bronchopulmonary dysplasia did not decline significantly with advancing gestational age, after controlling for other factors. Obstetric intervention and aggressive neonatal resuscitation have increased for pregnancies delivered between 23 and 26 weeks of gestation over the past decade. Although survival has increased over time and with advancing gestational age at delivery, short term morbidity in survivors is similar, regardless of gestational age in this cohort. A brief delay in delivery of those pregnancies who are at risk for delivery between 23 and 26 weeks of gestation may improve survival, although short term morbidity in survivors will not be affected substantially.