Interactive Effects of Maternal Vitamin D Status and Socio-Economic Status on the Risk of Spontaneous Abortion: Evidence from Henan Province, China.

Shiqi Lin,Lijun Pei,Jian Chai,Lifang Jiang,Yuan Zhang,Jiajia Li,Xuejun Shang

doi:10.3390/nu14020291

Abstract

Background: Maternal vitamin D deficiency might generate adverse reproductive outcomes, and socio-economic inequalities in micronutrient-related diseases have often been found. This study aimed to explore the interactive effects of maternal vitamin D status and socio-economic status (SES) on risk of spontaneous abortion. Methods: A population-based case–control study was conducted including 293 women with spontaneous abortion and 498 control women in December 2009 and January, 2010 in Henan Province, China. Information on pregnancy outcomes, maternal demographic, lifestyle and exposure factors and blood samples were collected at the same time. Vitamin D deficiency was defined as 25(OH)D < 20 ng/mL. SES index was constructed with principal component analysis by aggregating women’s and their husbands’ education level and occupation, and household income and expenditure. Interactive effects were assessed on a multiplicative scale with ratio of the odds ratio (ROR). Results: Compared to those with high SES and vitamin D sufficiency, women with vitamin D deficiency and low SES index had an increased risk of spontaneous abortion (aOR: 1.99; 95% CI: 1.23–3.23). The ROR was 2.06 (95% CI: 1.04–4.10), indicating a significant positive multiplicative interaction. Conclusions: Maternal low SES may strengthen the effect of vitamin D deficiency exposure on spontaneous abortion risk in this Chinese population.

Highlights

Spontaneous abortion could generate physical, psychosocial as well as economic burdens on families and the whole society [1]
Considering vitamin D deficiency is very prevalent in Chinese women of childbearing age [13,19,20,21], and considering the costs created by spontaneous abortion, it is an urgent need to find whether this deficiency is one of the causes of spontaneous abortion
This result agrees with previous studies suggesting vitamin D’s vital role in successful pregnancy and fetal growth: vitamin D plays a role in immunoregulation and trophoblast invasion [15,16], both of which are key to implantation [32]; vitamin D is important for a healthy pregnancy, as it is related to calcium metabolism in the myometrium, has a direct role in the production of antimicrobial peptides and may help prevent infection during pregnancy [41]

Summary

Introduction

Spontaneous abortion could generate physical, psychosocial as well as economic burdens on families and the whole society [1]. A prospective cohort study of pregnant women in Denmark has explored the relationship between maternal serum 25-hydroxyvitamin D [25(OH)D] and the risk of subsequent spontaneous abortion and found that the concentration of 25(OH)D < 50 nmol/L was associated with over 2-fold increased adjusted hazard ratio (HR) for first-trimester spontaneous abortion (HR: 2.50; 95% CI: 1.10, 5.69) [17]. This study aimed to explore the interactive effects of maternal vitamin D status and socio-economic status (SES) on risk of spontaneous abortion. Conclusions: Maternal low SES may strengthen the effect of vitamin D deficiency exposure on spontaneous abortion risk in this Chinese population

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Discussion

Conclusion