Variation in plasma 25-hydroxyvitamin D2 and D3 in normal pregnancy with gestational age, sampling season, and complications: A longitudinal cohort study

Vitamin D binding protein correlate with estrogen increase after administration of human chorionic gonadotropin but do not affect ovulation, embryo, or pregnancy outcomes

Background

Vitamin D binding protein (DBP) might increase substantially after ovarian stimulation and hence could be associated with IVF/ICSI outcomes because it determines the fraction of free bioavailable 25(OH) vitamin D. In this study, we aim to determine whether DBP is associated with E2 level after ovarian stimulation and IVF/ICSI outcomes.

Design

Post-hoc analysis of a prospective observational cohort.

Setting

Single-center study.

Participants

2569 women receiving embryo transfer.

Intervention

None.

Main outcome measures

The main outcomes were oocyte and embryo quality as well as pregnancy outcomes.

Results

DBP concentration correlates with E2 on hCG day (=day of inducing ovulation with hCG; correlation coefficient r = 0.118, P<0.001) and E2 x-fold change to baseline level (r = 0.108, P<0.001). DBP is also positively correlated with total 25(OH)D (r = 0.689, R2 = 0.475, P<0.001) and inversely with free 25(OH)D (r=-0.424, R2=0.179, P<0.001), meaning that E2-stimulated DBP synthesis results in a decrease of free 25(OH)D during ovarian stimulation. However, such alteration does not affect IVF/ICSI outcomes when considering confounding factors, such as the number and quality of oocytes nor embryo quality as well as pregnancy outcomes.

Conclusion

DBP concentration correlates with the degree of E2 increase after ovarian stimulation. DBP is also positively correlated with total 25(OH)D and inversely with free 25(OH)D, suggesting that the proportion of free 25(OH)D decreases during ovarian stimulation caused by E2-stimulated DBP synthesis. However, such alteration does not affect clinical IVF/ICSI outcomes.

Plasma fibulin-1 levels during pregnancy and delivery: a longitudinal observational study

Background

Fibulin-1 is an extracellular matrix protein expressed at high levels in the placenta. Elevated circulating fibulin-1 have been observed in women with severe pre-eclampsia, whereas low levels have been found in the fetal membranes, prior to membrane rupture. The aim of the study was primarily to evaluate plasma fibulin-1 during expected normal pregnancy and delivery, and secondarily to explore fibulin-1 levels in women developing pre-eclampsia or preterm premature rupture of fetal membranes (PPROM).

Methods

From the historical longitudinal cohort originally consisting of 801 healthy Danish women with a singleton pregnancy, 128 women (632 samples) were selected. Of these, 107 women had normal pregnancies, nine experienced PPROM, and 12 pre-eclampsia. All samples were analyzed for fibulin-1, and levels were compared with blood donors. Differences in mean fibulin-1 between groups were estimated using a linear mixed model.

Results

The mean concentration of fibulin-1 in 120 blood donors was 15.7 µg/mL, (25th-75th-percentiles, 12.3–18.2), with no significant difference in groups stratified by gender or age. Compared to baseline levels in week 12–20, fibulin-1 levels increased significantly from week 29–34 (estimated difference, 5.6 µg/mL; standard error, 1.7; p < 0.001) and 35–42 (12.5 µg/mL; 1.6; p < 0.001) and normalized after birth. The decrease at delivery tended to be more pronounced after elective (-7.0 µg/mL; 2.3; p = 0.002) and emergency (-5.6 µg/mL; 2.9; p = 0.05) cesarean section than after vaginal delivery (reference group). Women who developed PPROM had lower fibulin-1 levels throughout their pregnancies (-11.6 µg/mL; 4.2; p = 0.006). We did not observe a correlate between late pre-eclampsia and fibulin-1 (-0.2 µg/mL; 3.0; p = 0.9).

Conclusions

Fibulin-1 was above non-pregnant levels at week 12 and increased significantly throughout pregnancy. We observed an association between low levels of fibulin-1 and PPROM. Further studies are needed to examine if fibulin-1 could serve as biomarker for the risk of PPROM. However, its role in late preeclampsia is doubtful.

Trial registration

The study was conducted in accordance with the Declaration of Helsinki. The participants provided written informed consent, including storage for future use. The study was approved on July 18, 2005 by The Danish National Committee on Bioethics (No. KA 05065 and S-20,090,061) and the Danish Data Protection Agency.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04110-y.

Longitudinal Vitamin D Deficiency Among Malaysian Pregnant Women and Its Correlation With Neonatal Serum 25-Hydroxyvitamin D Levels

Objective: This study aimed to investigate the longitudinal relationship between maternal vitamin D concentrations during pregnancy and neonatal vitamin D concentrations at birth.

Materials and Methods: A prospective cohort of 236 healthy pregnant women from various ethnicity in early pregnancy (≤20 weeks of pregnancy) was followed at late pregnancy (28–40 weeks of pregnancy) and birth. Maternal serum 25-hydroxyvitamin D (25(OH)D) was assessed at early pregnancy (baseline) and late pregnancy, while neonatal cord serum 25(OH)D at birth. General estimating equations (GEE) were used to analyze the longitudinal association of maternal serum 25(OH)D levels during pregnancy and neonatal cord serum 25(OH)D levels at birth with adjusting for the time exposure, maternal weight gain, ethnicity, and skin type.

Results: The results showed that the prevalence of vitamin D deficiency (25(OH)D <50 nmol/L) was at 89.9, 92.2, and 96.1% in early, late pregnancy and in neonatal cord serum, respectively. The GEE analysis showed a trend that longitudinal vitamin D deficiency during pregnancy leads to lower vitamin D concentrations in neonatal cord blood (RR = 1.17; 95% CI (1.05–1.36); p = 0.04).

Conclusion: Longitudinal vitamin D deficiency during pregnancy leads to vitamin D deficiency in neonates at birth. A further trial is needed to affirm this association.

Predictors of circulating vitamin D levels in healthy mid-life Singaporean women

Vitamin D levels were lowest in Indian and Malay compared to Chinese women, and in younger and employed women. The main reason for hypovitaminosis D in study women was deficient cutaneous production. Supplementation in regions with abundant sunshine should consider ethnicity and opportunities for exposure to sunlight.

INTRODUCTION

Little is known about variations in circulating vitamin D levels in multiethnic mid-life women living in communities with year-round sunlight. Our study describes the circulating vitamin D levels and their sociodemographic predictors in mid-life Singaporean women.

METHODS

Prospective cross-sectional study of healthy Singaporean women, age 45-69 years, who were not consuming vitamin D supplements. Total 25-hydroxyvitaminD [25(OH)D], the sum of 25(OH)D₂ and 25(OH)D₃, was measured by liquid chromatography-tandem mass spectrometry.

RESULTS

The analytic cohort of 721 women, mean age 55.2±6.0 (±SD) years, was of Chinese (82%), Indian (11%), and Malay (7%) ethnicity. Their mean 25(OH)D level was 24.8±7.8ng/mL. One-third (32.6%) of the women had deficient 25(OH)D (≤20ng/mL) and 3.5% were severely deficient (<12ng/mL). 25(OH)D₃ comprised 98% of the total circulating 25(OH)D level. Adjusted mean total 25(OH)D levels were significantly lower for women of Indian and Malay (vs Chinese) ethnicity, who were premenopausal or working outside the home. Indian and Malay women had higher odds (adjusted OR 5.58 (95% CI 3.22, 9.87) and 3.83 (95% CI 1.97, 7.57), respectively) of low 25(OH)D compared to Chinese women. Obesity was not an independent predictor of low 25(OH)D, as its strong crude association was confounded by ethnicity. The adjusted odds of low 25(OH)D was reduced in women ≥65 years (adjusted OR 0.37 (95% CI 0.14, 0.87)) compared to those aged 45-55 years.

CONCLUSION

One-third of mid-life Singaporean women were 25(OH)D deficient, and the major independent predictors of deficiency were Indian or Malay ethnicity and younger age. Vitamin D supplementation in mid-life women should be targeted to those with documented deficiency or limited cutaneous production.

Vitamin D Deficiency in Mexican Pregnant Women: Is Supplementation with ≤400 IU/day Enough?

Controversy remains surrounding vitamin D routine supplementation in healthy pregnancy, and the doses are unclear. The aim of this study was to describe maternal vitamin D status throughout pregnancy in a group of Mexican women and evaluate the effect of frequently prescribed doses of vitamin D3 on longitudinal 25-OH-D concentrations, adjusting for obesity, season, and other factors. We conducted a cohort study (Instituto Nacional de Perinatología-INPer) (2017-2020)) of healthy pregnant women without complications. Pregestational overweight/obesity (body mass index ≥ 25), vitamin D3 supplementation (prescribed by physician; 0-250, 250-400, and >400 IU/day), and serum 25-OH-D concentrations (ELISA) were evaluated in each trimester of pregnancy. Vitamin D deficiency or insufficiency was computed (<20 and <30 ng/mL, respectively). We studied 141 adult women; 58.5% had pregestational obesity or overweight. In the first trimester, 45.8% of the women were supplemented with vitamin D3; 51.4% had vitamin D insufficiency and 37.3%, deficiency. In the third trimester, 75.4% of the women were supplemented, and 20% of them still had deficiency. The final general mixed linear model showed that 25-OH-D significantly increased throughout pregnancy (p < 0.001); the highest increase was observed in the third trimester in women with doses >400 IU/day of vitamin D3 (+4 ng/mL, 95% CI: 1.72-8.11 ng/mL). In winter/autumn, 25-OH-D concentrations were also lower (p ≤ 0.05). In this group of pregnant Mexican women, the prevalence of vitamin D deficiency and insufficiency was high. A higher increase in 25-OH-D concentrations during pregnancy was observed when the women were supplemented with >400 IU/day. Common supplementation doses of 250-400 IU/day were insufficient for achieving an adequate maternal vitamin D status.

Is First Trimester Maternal 25-Hydroxyvitamin D Level Related to Adverse Maternal and Neonatal Pregnancy Outcomes? A Prospective Cohort Study among Malaysian Women

Information on the role of 25-hydroxyvitamin D (25(OH)D) in preventing adverse pregnancy/neonatal outcomes is limited in Malaysia. This study aims to determine the relationship between the level of maternal 25(OH)D in the first trimester of pregnant women and their pregnancy/neonatal outcomes. A total of 60 pregnant women in the first trimester were recruited and followed until the end of their pregnancy. The occurrence of any antenatal, delivery, and neonatal complications was recorded. Their blood was collected in the first trimester for total serum 25(OH)D determination using enzyme-linked immunosorbent assay. Overall, 10% of the women had vitamin D deficiency, while 57% had vitamin D insufficiency in their first trimester. No statistically significant difference in 25(OH)D level/status was observed between women with or without antenatal and delivery complications (p > 0.05). No difference in maternal serum 25(OH)D level and vitamin D status was observed between neonates with or without complications (p > 0.05). In conclusion, there is a high prevalence of vitamin D insufficiency among Malaysian pregnant women, but it is not associated with adverse maternal and neonatal outcomes. More comprehensive studies should be planned to verify this relationship.