25-hydroxyvitamin-D (25(OH)D) level in the fetus entirely depends on the transport over placenta which is assumed to be obstructed with maternal levels <25nmol/L. Design Observational study. Setting Prospectively enrolling from September to December 2021 in a tertiary governmental hospital in a northern Emirate. Population Admission for spontaneous and elective labor. Methods 25(OH)D was analyzed in maternal serum at admission, respectively, in cord blood after delivery. Main outcome measures Factors affecting maternal and fetal 25(OH)D levels and the correlation between the two at delivery. Results 303 women were enrolled and 237 had complete maternal/umbilical cord blood samples. 138 (47.7%) of women were diagnosed with deficiency (25(OH)D<50nmol/L), whereas only 34 fetuses (13.8%) were deficient (25(OH)D<30nmol/L). The mean difference between maternal and cord blood 25(OH)D was negative in 91% of cases (-16.27nmol/L, SD=13.36). The correlation between maternal/umbilical cord levels was excellent (r = 0,906, p<0,000). After dividing into subgroups of maternal 25(OH)D levels, BMI, diabetes yes/no and delivery-mode the correlation was consistent, although the correlation coefficients in the subgroups of maternal 25(OH)D levels were lowered for all groups. Of factors studied, only the supplementation dose affected the maternal 25(OH)D level. 25(OH)D <50nmol/L was not associated to an increased risk for diabetes, preterm labor, preterm-rupture-of-membranes or low Apgar-score. Conclusion We found a higher 25(OH)D level in cord blood with consistent correlation to maternal levels. Of the studied factors only supplementation dose had significant impact on the maternal level. 25(OH)D <50nmol/l were not associated to increased risk for preterm-labor, preterm-rupture-of-membranes, diabetes or low AS.

Objective Determination of lactate in fetal scalp blood (FBS) during labor has been studied since the 1970s. The internationally accepted cut-off of >4.8mmol/L indicating fetal acidaemia is exclusive for the point-of-care device (POC) LactateProTM, which is no longer in production. The aim of this study was to present a new cut-off for scalp lactate based on neonatal outcomes with the use of StatstripLactate®/StatstripXpress® Lactate system, the only POC lactate meter designed for hospital use. Design Observational Study Setting January 2016 to March 2020 labouring women with an indication for FBS were prospectively included from seven Swedish and one Australian delivery unit. Population Inclusion criteria: singleton pregnancy, vertex presentation, ≥35+0 gestational weeks. Method Based on the optimal correlation between FBS lactate and cord pH/lactate, only cases with ≤25 minutes from FBS to delivery were included in the final calculations. Main outcome measures Metabolic acidosis in cord blood was defined as pH <7.05 plus BDecf >10 mmol/L and/or lactate >10 mmol/L. Results 3334 women were enrolled of which 799 were delivered within 25 minutes. The areas under the ROC curves (AUC) and corresponding optimal lactate cut-off values were as follows; metabolic acidosis AUC 0.87(95% CI:0.77-0.97), cut-off 5.7mmol/L; pH <7.0 AUC 0.83(95% CI:0.68-0.97), cut-off 4.6mmol/L; pH <7.05 plus BD ≥12mmol/L AUC 0.97(95% CI:0.92-1), cut-off 5.8mmol/L; Apgar score <7 at 5 minutes AUC 0.74(95% CI:0.63-0.86), cut-off 5.2mmol/L; and pH <7.10 plus composite neonatal outcome AUC 0.76(95% CI:0.67-0.85), cut-off 4.8mmol/L. Conclusions Suggested intervention threshold for fetal acidemia is scalp lactate of 5.2mmol/L using the StatstripLactate®/StatstripXpress®.