Moderate altitude impacts birth weight: 30 years retrospective sibling analyses using record linkage data.

OBJECTIVE: We investigated the effect of a change of altitude of maternal living address on infant birth weight. METHOD: Data on infant birth weights of the first and second pregnancies from same women were extracted from all Austrian birth certificates between 1984 and 2016. RESULTS: A total of 544,624 pair pregnancies were identified and analyzed. We observed a statistically significant interaction (p < .0001) between altitudes of two births and birth weight. Among women having first birth at low altitude (200 m), the estimated second mean birth weight was 3567 g for those remained at low altitudes, and reduced to 3536 g for those ascended (1200 m). In contrast, among women having first births at high altitudes, the estimated birth weight of second birth at high altitude was 3414 g, yet increased to 3499 g compared to those descended to lower altitudes. CONCLUSION: We demonstrated a longitudinal negative effect of altitude on birth weight within the same mother from first and second birth. This association is likely to be casual. Relocation of mothers within low-to-medium altitude level may have profound effects on infants' birth weight.

Metabolomic prediction of fetal congenital heart defect in the first trimester.

OBJECTIVE: The objective of the study was to identify metabolomic markers in maternal first-trimester serum for the detection of fetal congenital heart defects (CHDs). STUDY DESIGN: Mass spectrometry (direct injection/liquid chromatography and tandem mass spectrometry) and nuclear magnetic resonance spectrometry-based metabolomic analyses were performed between 11 weeks' and 13 weeks 6 days' gestation on maternal serum. A total of 27 CHD cases and 59 controls were compared. There were no known or suspected chromosomal or syndromic abnormalities indicated. RESULTS: A total of 174 metabolites were identified and quantified using the 2 analytical methods. There were 14 overlapping metabolites between platforms. We identified 123 metabolites that demonstrated significant differences on a univariate analysis in maternal first-trimester serum in CHD vs normal cases. There was a significant disturbance in acylcarnitine, sphingomyelin, and other metabolite levels in CHD pregnancies. Predictive algorithms were developed for CHD detection. High sensitivity (0.929; 95% confidence interval [CI], 0.92-1.00) and specificity (0.932; 95% CI, 0.78-1.00) for CHD detection were achieved (area under the curve, 0.992; 95% CI, 0.973-1.0). CONCLUSION: In the first such report, we demonstrated the feasibility of the use of metabolomic developing biomarkers for the first-trimester prediction of CHD. Abnormal lipid metabolism appeared to be a significant feature of CHD pregnancies.

Maternal serum vitamin D at 11-13 weeks in pregnancies delivering small for gestational age neonates.

OBJECTIVES: To determine if maternal serum levels of 25(OH)D at 11-13 weeks' gestation are altered in pregnancies that subsequently deliver small for gestational age (SGA) neonates and whether the levels are related to placental function reflected in serum concentration of pregnancy-associated plasma protein-A (PAPP-A). METHODS: Serum 25(OH)D and PAPP-A were measured at 11-13 weeks in 150 singleton pregnancies that delivered SGA neonates and 1,000 appropriate for gestational age (AGA) controls. The median 25(OH)D and PAPP-A multiple of the unaffected median (MoM) in the outcome groups were compared. RESULTS: In the SGA, the median serum 25(OH)D and PAPP-A were significantly decreased (0.78 vs. 1.00 MoM, p < 0.0001 and 0.78 vs. 1.00 MoM, p < 0.0001, respectively). The incidence of 25(OH)D levels below the 10th percentile was significantly higher in the SGA than the AGA group in Caucasian women (p = 0.002) but not in those of African racial origin (p = 0.183). There was no significant association between 25(OH)D MoM and PAPPA MoM in either the SGA or the AGA groups. CONCLUSION: Serum 25(OH)D levels at 11-13 weeks are decreased in pregnancies of Caucasian women that deliver SGA neonates but not in those of African racial origin. The decrease in 25(OH)D levels is unrelated to placental function.

Normal range of maternal serum vitamin d at 11-13 weeks' gestation.

OBJECTIVE: To establish a normal range of maternal serum levels of total vitamin D at 11-13 weeks' gestation and examine factors from maternal characteristics and obstetric history affecting these levels. METHODS: Serum 25-hydroxyvitamin D [25(OH)D] was measured by liquid chromatography-tandem mass spectrometry in 1,000 singleton pregnancies with normal outcome. Multiple regression analysis was used to determine the factors from maternal characteristics and obstetric history affecting the measured 25(OH)D levels and the regression model was used to convert each measurement into a multiple of the median (MoM). RESULTS: Serum 25(OH)D increased with maternal age, decreased with body mass index (BMI), it was higher in the summer than other months and when conception was assisted than spontaneous and it was lower in cigarette smokers and in women of African and Asian racial origin compared to Caucasians. In Caucasian, non-smoking women, with BMI below 25, conceiving spontaneously and sampled in the summer months the estimated 5th, 10th, 50th, 90th and 95th percentiles of 25(OH)D were 10.8, 14.7, 30.7, 48.2 and 55.7 ng/ml, respectively. CONCLUSION: Maternal serum 25(OH)D concentration at 11-13 weeks is affected by season of blood sampling and maternal characteristics.