Fetal abdominal wall defects and mode of delivery: a systematic review.

OBJECTIVE: To determine whether there is sufficient evidence to support cesarean delivery over vaginal delivery in women carrying a fetus with an abdominal wall defect. DATA SOURCES: An OVID MEDLINE search of English language abstracts using medical subject heading terms "gastroschisis," "omphalocele," and "fetal abdominal wall defects" was performed. The generated list of articles was supplemented by a review of their bibliographies and the bibliographies of obstetric texts. STUDY SELECTION: A total of 27 peer-reviewed observational studies were identified, and 15 were included in the meta-analysis. Our primary inclusion criterion was the reporting of neonatal outcomes for infants with abdominal wall defects who delivered vaginally and who delivered by cesarean section. Studies were excluded if they were a case series or if neonatal outcomes could not be ascertained from the data presented in the manuscript. TABULATION, INTEGRATION, AND RESULTS: Standard meta-analytic techniques were applied to assess the question of whether cesarean delivery improves neonatal outcomes in infants with abdominal wall defects. There was no significant relationship between mode of delivery and the rate of primary fascial repair (random effects model: pooled relative risk [RR] 1.22, 95% confidence interval [CI] 0.99, 1.51), neonatal sepsis (random effects model: pooled RR 0.70, 95% CI 0.30, 1.62), or pediatric mortality (random effects model: pooled RR 1.14, 95% CI 0.59, 2.21). Additionally, there was no significant relationship between mode of delivery and time until enteral feeding or length of hospital stay. CONCLUSION: The available data do not provide evidence to support a policy of cesarean delivery for infants with abdominal wall defects.

Amniotic fluid matrix metalloproteinase-8 indicates intra-amniotic infection.

OBJECTIVE: This study was undertaken to determine whether matrix metalloproteinase-8, which is produced by neutrophils, is a useful marker for the detection of intra-amniotic infection. STUDY DESIGN: We performed a case-control study using enzyme-linked immunosorbent assays to detect matrix metalloproteinase-8 in 77 amniotic fluid specimens that were obtained by amniocentesis from women with preterm contractions or preterm labor and intact fetal membranes (n = 66) and from women with preterm premature rupture of membranes (n = 11). RESULTS: Thirty women had culture-proven intra-amniotic infection (cases), 21 of whom had intact membranes. After constructing receiver operating characteristic curves to establish the optimal threshold concentration of matrix metalloproteinase-8 for a positive test result, we detected matrix metalloproteinase-8 in 27 of 30 women with intra-amniotic infection; only 10 of 47 control specimens contained matrix metalloproteinase-8 (P <.001; odds ratio, 33.3; 95% CI, 8.4, 132.7). Matrix metalloproteinase-8 was present in 20 of 21 women with intact membranes and intra-amniotic infection and in only 10 of 45 control subjects (P <.001; odds ratio, 70.0; 95% CI, 8.3, 587.6). Among women with intact membranes, the sensitivity of the assay was 0.95 and the specificity was 0.78. CONCLUSION: Our results indicate that matrix metalloproteinase-8 is highly correlated with intra-amniotic infection and that enzyme-linked immunosorbent assay for matrix metalloproteinase-8 may be a clinically useful test for the diagnosis of intra-amniotic infection in women with preterm contractions and preterm labor.

Prediction of delivery among women with early preterm labor by means of clinical characteristics alone.

OBJECTIVE: This study was undertaken to assess whether individual clinical factors or combinations thereof could be used to accurately predict the risk of delivery within 1 week of admission among women with preterm labor and minimal cervical dilatation. STUDY DESIGN: We performed a case-control study of patients admitted to our institution with preterm labor and minimal cervical dilatation. A case patient was a patient who sought treatment with uterine contractions between 24 and 34 weeks' gestation with cervical dilatation 70 potential predictors was recorded. Statistical analysis consisted of bivariate and multivariable methods. We also generated a multivariable clinical predictive model with the purpose of detecting a proportion as high as possible of those destined to be delivered within 1 week (high sensitivity). We estimated that we would need 50 case patients and 150 control subjects to detect an odds ratio of 2.5 for risk factors with a prevalence of 20%, an alpha error of.05, a beta error of.20, and a control subject/case patient ratio of 3:1. RESULTS: Three variables were eligible for inclusion in our logistic models according to the bivariate analyses-bleeding on admission, substance abuse, and admission white blood cell count >/=14,000 cells/microL. The simplest and most favorable model included only 2 variables, bleeding and substance abuse, and yielded a sensitivity of 46% and a specificity of 76%. The full 3-variable model had similar test characteristics. For no model were we able to achieve a sensitivity >/=50%. CONCLUSION: The results of this case-control study suggest that combinations of clinical factors do not yield an adequate level of discrimination to be used alone for predicting the likelihood of delivery within 1 week among patients with minimal degrees of cervical dilatation.

Predicting delivery within 48 hours in women treated with parenteral tocolysis.

OBJECTIVE: To develop a prediction rule using clinical admission characteristics for women treated with parenteral tocolysis for preterm labor who are at highest risk of delivery within 48 hours. METHODS: We performed a case-control study of patients treated with magnesium sulfate for idiopathic preterm labor. A case was defined as a patient who received magnesium sulfate tocolysis and delivered within 48 hours of admission. We selected a 48-hour delay to delivery as a clinically relevant endpoint for the maximization of steroid benefit. Controls were patients who received magnesium sulfate tocolysis and remained undelivered 48 hours after admission. Cases and controls were identified by merging a pharmacy billing database with International Classification of Disease codes for premature labor. Medical records were reviewed and risk factor information was obtained. We focused on risk factors within the first hour of admission, because our goal was to identify patients at high risk of delivery early in their hospital course. Backward stepwise logistic regression was used to develop explanatory and predictive models. The focus of the predictive model was to maximize the test's sensitivity and negative predictive value. RESULTS: We identified 50 cases and 150 controls. The following six variables were included in the initial multivariable models based on bivariate analyses: white blood cell count at least 14.0 (1000/microL), cervical dilation at least 2 cm, bleeding, substance abuse, parity, and previous abortion. A two-variable model containing cervical dilation and bleeding had an overall accuracy of 73%, sensitivity of 62%, and specificity of 76%, and it was as sensitive and specific as more complex models. CONCLUSION: Cervical dilation of at least 2 cm and bleeding on admission had an overall accuracy of 73% in predicting the likelihood of delivery within 48 hours in women receiving magnesium sulfate.