Characterizing and Forecasting Individual Weight Changes in Term Neonates.

OBJECTIVES: To develop a mathematical, semimechanistic model characterizing physiological weight changes in term neonates, identify and quantify key maternal and neonatal factors influencing weight changes, and provide an online tool to forecast individual weight changes during the first week of life. STUDY DESIGN: Longitudinal weight data from 1335 healthy term neonates exclusively breastfed up to 1 week of life were available. A semimechanistic model was developed to characterize weight changes applying nonlinear mixed-effects modeling. Covariate testing was performed by applying a standard stepwise forward selection-backward deletion approach. The developed model was externally evaluated on 300 additional neonates collected in the same center. RESULTS: Weight changes during first week of life were described as a function of a changing net balance between time-dependent rates of weight gain and weight loss. Males had higher birth weights (WT0) than females. Gestational age had a positive effect on WT0 and weight gain rate, whereas mother's age had a positive effect on WT0 and a negative effect on weight gain rate. The developed model showed good predictive performance when externally validated (bias = 0.011%, precision = 0.52%) and was able to accurately forecast individual weight changes up to 1 week with only 3 initial weight measurements (bias = -0.74%, precision = 1.54%). CONCLUSIONS: This semimechanistic model characterizes weight changes in healthy breastfed neonates during first week of life. We provide a user-friendly online tool allowing caregivers to forecast and monitor individual weight changes. We plan to validate this model with data from other centers and expand it with data from preterm neonates.

Accuracy of angiogenic biomarkers at ⩽20weeks' gestation in predicting the risk of pre-eclampsia: A WHO multicentre study.

OBJECTIVE: To assess the accuracy of angiogenic biomarkers to predict pre-eclampsia. DESIGN: Prospective multicentre study. From 2006 to 2009, 5121 pregnant women with risk factors for pre-eclampsia (nulliparity, diabetes, previous pre-eclampsia, chronic hypertension) from Argentina, Colombia, Peru, India, Italy, Kenya, Switzerland and Thailand had their serum tested for sFlt-1, PlGF and sEng levels and their urine for PlGF levels at ⩽20, 23-27 and 32-35weeks' gestation (index tests, results blinded from carers). Women were monitored for signs of pre-eclampsia, diagnosed by systolic blood pressure ⩾140mmHg and/or diastolic blood pressure ⩾90mmHg, and proteinuria (protein/creatinine ratio ⩾0.3, protein ⩾1g/l, or one dipstick measurement ⩾2+) appearing after 20weeks' gestation. Early pre-eclampsia was defined when these signs appeared ⩽34weeks' gestation. MAIN OUTCOME MEASURE: Pre-eclampsia. RESULTS: Pre-eclampsia was diagnosed in 198 of 5121 women tested (3.9%) of whom 47 (0.9%) developed it early. The median maternal serum concentrations of index tests were significantly altered in women who subsequently developed pre-eclampsia than in those who did not. However, the area under receiver operating characteristics curve at ⩽20weeks' gestation were closer to 0.5 than to 1.0 for all biomarkers both for predicting any pre-eclampsia or at ⩽34weeks' gestation. The corresponding sensitivity, specificity and likelihood ratios were poor. Multivariable models combining sEng with clinical features slightly improved the prediction capability. CONCLUSIONS: Angiogenic biomarkers in first half of pregnancy do not perform well enough in predicting the later development of pre-eclampsia.

The effect of migration background on obstetric performance in Switzerland.

OBJECTIVES: Population-based analysis to compare perinatal outcome between immigrant women and women from the Western industrialized world (WIW). METHODS: Singleton pregnancies of a cohort that was followed from the first trimester to delivery at the University Women's Hospital Basel, Switzerland, were retrospectively analysed. Data were extracted from 203 patient records. Multiple logistic and linear regression analyses were used to determine the impact of origin on perinatal outcome. RESULTS: Immigrants and women from WIW countries were comparable regarding number of pregnancy control visits. Immigrant women were younger, had more children, higher pre-pregnancy body mass index and were more often taking medication of any kind during pregnancy. Migration was only predictive for shorter gestations (p < 0.01). A trend for a lower frequency of gestational hypertension and labour inductions, and a higher frequency of spontaneous delivery and lower birth weights were observed. CONCLUSIONS: Migration background was associated with shorter gestations and lower birth weight. This was not due to differences in antenatal care since both study groups were followed at the same clinic with the same guidelines and had the same number of consultations during pregnancy. Higher stress levels due to migration and lower socioeconomic living standards, nutrition, and genetic factors are possible contributors to these findings.