[Relationship of plasma vitamin A levels between neonates and pregnant women in third trimester].

OBJECTIVE: To study the correlation of plasma vitamin A (VitA) levels between neonates and pregnant women in third trimester. METHODS: A total of 688 pregnant women were recruited in Yuanshi and Laoting counties of Hebei Province, from May to June 2009. Venous blood samples of women before delivery and cord blood samples of newborns were collected and measured for retinol (retinol concentration was used to reflect VitA level) using high performance liquid chromatography assay. According to venous blood plasma retinol concentration, maternal VitA nutritional status was divided into deficiency (<0.70 µmol/L), marginal deficiency (0.70-<1.05 µmol/L), and sufficiency (≥1.05 µmol/L). According to cord blood plasma retinol concentration, neonatal VitA nutritional status was divided into deficiency (<0.35 µmol/L), marginal deficiency (0.35-<0.70 µmol/L), and sufficiency (≥0.70 µmol/L); neonatal VitA relative deficiency was further defined as cord blood plasma retinol concentration lower than the 10th percentile. VitA placental transport ratio was defined as retinol concentration in the neonates divided by that in pregnant women. Multivariable fractional polynomials (MFP) model and Pearson correlation were used to study the dose-response relationship between maternal and neonatal plasma VitA levels, Logistic regression model to estimate the effect of maternal VitA nutritional status on neonatal VitA deficiency, and MFP model and Spearman correlation to describe the relationship between maternal VitA level and VitA placental transport ratio. RESULTS: The average retinol concentration of the pregnant women was (1.15±0.30) µmol/L, and the prevalence of VitA deficiency and marginal deficiency were 4.5% and 37.8%, respectively. Average retinol concentration of the neonates was (0.78±0.13) µmol/L, and no neonates were VitA deficiency, 28.2% of the neonates were marginal deficiency. After multivariable adjustment, the VitA level of the neonates was positively and linearly related to maternal VitA level (pm=1, P<0.05), with the corresponding Pearson correlation coefficient of 0.13 (P<0.01). As compared with the women with sufficient VitA, those with VitA deficiency (crude OR=2.20, 95%CI:1.04-4.66) and marginal deficiency (crude OR=1.43, 95%CI:1.01-2.02) had higher risks to deliver neonates with VitA marginal deficiency; while the risks turned to be non-significant after multivariable adjustment. The pregnant women with VitA deficiency had higher risk to deliver neonates with relative VitA deficiency before and after multivariable adjustment (crude OR=3.02, 95%CI:1.21-7.50; adjusted OR=2.76, 95%CI:1.05-7.22). The maternal VitA level was negatively and non-linearly correlated with placental transport ratio (pm= -0.5, P<0.05), with corresponding adjusted Spearman correlation coefficient of -0.82 (P<0.001). CONCLUSION: There was a positive linear dose-response relationship between VitA levels of newborns and pregnant women in third trimester, indicating that neonatal VitA storing levels at birth was affected by maternal VitA nutritional status.

Association of elective cesarean delivery with metabolic measures in childhood: A prospective cohort study in China.

BACKGROUND AND AIMS: Cesarean delivery may increase the risk of childhood obesity, a precursor of metabolic syndrome (MetS). We aimed to investigate the association of elective cesarean delivery (ElCD) with MetS and its components in a Chinese birth cohort. METHODS AND RESULTS: This cohort included 1467 children (737 delivered by ElCD and 730 by spontaneous vaginal delivery [SVD]) who were followed up at the age of 4-7 years in 2013. MetS was defined as the presence of ≥3 components: central obesity, hypertriglyceridemia, low high-density lipoprotein (HDL), high fasting glucose, and hypertension. Of the 1467 children, 93 (6.3%) were categorized as having MetS: 50 (6.8%) delivered by ElCD and 43 (5.9%) by SVD. After multivariable adjustment, ElCD was not associated with MetS (adjusted odds ratio [AOR] 1.15, 95% confidence interval [CI] 0.74, 1.78) or certain components including hypertriglyceridemia, low HDL, and high fasting glucose but was associated with central obesity (AOR 1.33, 95% CI 1.02, 1.72) and hypertension (AOR 1.50, 95% CI 1.15, 1.96), as well as higher levels of total cholesterol (3.43 vs. 3.04 mmol/L; P < 0.001), low-density lipoprotein-cholesterol (1.77 vs. 1.67 mmol/L, P = 0.002), fasting glucose (5.08 vs. 5.02 mmol/L, P = 0.022), systolic (97.57 vs. 94.69 mmHg, P < 0.001)/diastolic blood pressure (63.72 vs. 62.24 mmHg, P < 0.001), and BMI (15.46 vs. 14.83 kg/m2, P < 0.001) than SVD. CONCLUSIONS: ElCD is not associated with MetS in early to middle childhood but is associated with its components including central obesity and hypertension, as well as various continuous indices.