The relationship between 25-hydroxyvitamin D concentration in early pregnancy and pregnancy outcomes in a large, prospective cohort

Abstract

Type of publicationArticle (peer-reviewed)Link to publisher's version http://dx.doi.org/10.1017/S0007114516003202Access to the full text of the published version may require a subscription. Rights © The Authors 2016Embargo information Access to this article is restricted until 12 months after publication by the request of the publisher Abstract Vitamin D insufficiency and deficiency have been associated with an increased risk of adverse pregnancy outcomes. Controversy remains as findings have been inconsistent between disparate populations. The aim of this study was to investigate the relationship between vitamin D status and pregnancy outcomes in a large, prospective pregnancy cohort. 25-Hydroxyvitamin D concentration was analysed in serum samples collected at 15 weeks of gestation from 1710 New Zealand women participating in a large, observational study. Associations between vitamin D status and pre-eclampsia, preterm birth, small for gestational age (SGA) and gestational diabetes were investigated. The mean 25-hydroxyvitamin D concentration was 72·9 nmol/l. In all, 23 % had 25-hydroxyvitamin D concentrations <50 nmol/l, and 5 % of participants had concentrations <25 nmol/l. Women with 25-hydroxyvitamin D concentrations <75 nmol/l at 15 weeks of gestation were more likely to develop gestational diabetes mellitus than those with concentrations >75 nmol/l (OR 2·3; 95 % CI 1·1, 5·1). However, this effect was not significant when adjustments were made for BMI and ethnicity (OR 1·8; 95 % CI 0·8, 4·2). 25-Hydroxyvitamin D concentration at 15 weeks was not associated with development of pre-eclampsia, spontaneous preterm birth or SGA infants. Pregnancy complications were low in this largely vitamin D-replete population.Key words: Vitamin D: Gestational diabetes mellitus: Pre-eclampsia Much progress has been made in the screening, diagnosis and management of important pregnancy disorders, but little progress has been made in the prevention of such disorders. Preeclampsia remains the second most common cause of maternal death worldwide (1) . Prematurity, mostly due to spontaneous preterm birth, is the leading cause of death among infants worldwide (2) . This is followed by growth restriction in term infants (3) . Furthermore, infants born preterm or with low birth weight have an increased risk of CVD and metabolic diseases later in life, the leading cause of death in adulthood (4) . The incidence of gestational diabetes mellitus (GDM) is increasing rapidly worldwide (5) and is associated with lifelong risks of metabolic disease in both mother and baby (6,7) . An association between low vitamin D and adverse pregnancy outcomes was first identified in the early 2000s (8) ; consequently, vitamin D has been postulated as a possible intervention strategy to reduce pregnancy complications. A recent meta-analysis found that low vitamin D, defined variably by the authors of included studies, was associated with an increased likelihood of pre-eclampsia (OR 1·79; 95 % CI 1·25, 2·58), small-for-gestational age (SGA) babies (OR 1·...

Relationship between vitamin D and gestational diabetes in overweight or obese pregnant women may be mediated by adiponectin

“…However, recent large‐scale studies not included in these meta‐analyses reported no relationship between 25(OH)D and post‐OGTT glucose levels or GDM risk . Most of these studies involved predominantly non vitamin D deficient women (25(OH)D > 70–132 nmol/L). This may explain their null findings since relationships between vitamin D and glucose metabolism are thought to be more pronounced in vitamin D deficient women .…”

Does Vitamin D Deficiency in Different Periods of Gestation Have the Same Effect on Preterm Birth? A Systematic Review and Meta-Analysis

“…A total of 1639 were excluded after reading titles and/or abstracts, and 75 articles were subjected to a full-text review. After reading the full text, a total of 24 cohorts were invited to participate, which included 13 cohort studies [27][28][29][30][31][32][33][34][35][36][37][38][39], seven case-control studies [40][41][42][43][44][45][46] and four cross-sectional studies [47][48][49][50].…”

“…Because three studies [29][30][31] of 24 measured serum 25(OH)D concentrations at two or three periods of pregnancies, our meta-analysis included nine studies [28][29][30][31]36,39,41,44,46] in the first trimester, 11 studies [27,[30][31][32][33][34][35]37,38,40,43] in the second trimester, and nine studies [29][30][31]42,45,[47][48][49][50] in the third trimester.…”

“…In this review, 13 of the 24 observational studies clearly reported no effect of vitamin D deficiency during pregnancy on preterm birth, no matter whether in early pregnancy, in middle pregnancy, or in late pregnancy [27,28,[31][32][33]35,36,39,[44][45][46]48,49]. However, other studies showed different results.…”

“…The included studies from the United States, Canada, Australia, New Zealand, Spain, Netherlands, Swedish, Poland, Brazil, Kenya, China, Singapore and Thailand. A total of nine studies [28,30,31,33,37,40,[48][49][50] were from Asian countries, six [36,41,43,[45][46][47] from American countries, five [29,34,38,39,42] from European countries, three [27,35,44] from Oceanian countries, and one [32] was from African countries. Among 24 studies, 21 [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] cohort studies or case-control studies were appraised by NOS, resulting with scores above 6, while four [47][48][49][50] cross-sectional studies were appr...…”