Maternal BMI at the time of birth and selected risk factors associated with severe neonatal outcomes: a secondary analysis of the WHO Better Outcomes in Labour Difficulty (BOLD) project.

The main objective of this secondary analysis was to describe the nutritional status of the Better Outcomes in Labour Difficulty (BOLD) project study population and determine possible associations between maternal nutritional status (as reflected by maternal BMI at the time of birth) and severe neonatal outcomes (SNO). We also analysed previous and index maternal pathologies to determine associations with neonatal outcomes. We used the classification designed by Atalah for maternal BMI and compared with the Hyperglycaemia and Adverse Pregnancy Outcome study one. To describe the nutritional status of this population, figures of distribution and test of normality related to weight and BMI were presented for the women and their babies. To explore the association between maternal BMI data and SNO, the χ2 test was performed. To identify a maternal characteristic or a group of characteristics that could predict SNO, we used Fisher's exact test using previous maternal pathology collected in the BOLD project as well as that in the index pregnancy. In this study, BMI at the time of birth was not associated with neonatal near miss or death. We found that previous maternal obesity, diabetes and chronic hypertension were associated with SNO. Maternal pathology in the index pregnancy such as other obstetric haemorrhage, pre-eclampsia, anaemia and gestational diabetes was associated with SNO.

Low versus atmospheric oxygen tension for embryo culture in assisted reproduction: a systematic review and meta-analysis.

OBJECTIVE: To appraise the available evidence comparing low oxygen (LowO2) and atmospheric oxygen tension (AtmO2) for embryo culture. DESIGN: Systematic review and meta-analysis. SETTING: Not applicable. PATIENT(S): Women undergoing assisted reproduction using embryo culture. INTERVENTION(S): Embryo culture using LowO2 versus AtmO2. MAIN OUTCOME MEASURE(S): Reproductive, laboratory, and pregnancy outcomes. RESULT(S): A total of 21 studies were included in this review. All used O2 concentration between 5% and 6% in the LowO2 group. Considering the studies that randomized women/couples, we observed very low quality evidence that LowO2 is better for live birth/ongoing pregnancy (relative risk [RR] = 1.1, 95% confidence interval [CI] 1.0-1.3) and clinical pregnancy (RR = 1.1, 95% CI 1.0-1.2). Considering the studies that randomized oocytes/embryos, we observed low quality evidence of no difference of fertilization (RR = 1.0, 95% CI 1.0-1.0) and cleavage rate (RR = 1.0, 95% CI 1.0-1.1), and low quality evidence that LowO2 is better for high/top morphology at the cleavage stage (RR = 1.2, 95% CI 1.1-1.3). No studies comparing pregnancy outcomes were identified. Several studies used different incubators in the groups-a new model for the LowO2 group and an old model for the AtmO2 group. The risk of detection bias for the laboratory outcomes was high as embryologists were not blinded. CONCLUSION(S): Although we observed a small improvement (∼5%) in live birth/ongoing pregnancy and clinical pregnancy rates (PRs), the evidence is of very low quality and the best interpretation is that we are still very uncertain about differences in this comparison. The clinical equipoise remains and more large well-conducted randomized controlled trials are needed. They should use the same incubators in both groups and the embryologists should be blinded at least when evaluating laboratory outcomes.