Miscarriage 2 times more likely if low vitamin D – meta-analysis

Created May 2017

Meta-analysis of the effect of the maternal vitamin D level on the risk of spontaneous pregnancy loss.

Int J Gynaecol Obstet. 2017 May 13. doi: 10.1002/ijgo.12209.

Zhang H1, Huang Z2, Xiao L3, Jiang X1, Chen D1, Wei Y1.

* * 2.2 X more likely in first trimester if < 20 ng of Vitamin D * Note Vitamin D supplementation during pregnancy often does not start until second trimester – which is too late to reduce miscarriages** --- * Just 400 IU of daily Vitamin D reduced miscarriage (recurrent) by 3.5 times – RCT July 2016 * Miscarriage 70 percent more likely if low vitamin D (see also data on CYP27B1) – May 2016 * Miscarriage in first trimester 2.5X more likely if less than 20 ng of vitamin D – July 2015 * Second miscarriage associated with low vitamin D – review June 2018 * Miscarriage 32 percent more likely if work night shift (probably low Vitamin D) – April 2019 * Recurrent pregnancy loss (miscarriage) is associated with low vitamin D in 6 ways – March 2021 Pregnancy category starts with {include} 1. Healthy pregnancies need lots of vitamin D has the following summary {include} * Miscarriage 70 percent more likely if low vitamin D (see also data on CYP27B1) – May 2016 --- 1. See also web on Miscarriage * Early Pregnancy Loss Medscape Oct 2016 * "In the first trimester, embryonic causes of spontaneous abortion are the predominant etiology and account for 80-90% of miscarriages" * Statistics on Miscarriage including failure to implant and multiples (nothing about vitamin D)

BACKGROUND: he association between vitamin D deficiency and early spontaneous pregnancy loss (SPL) is unclear.

OBJECTIVES: To assess the association of serum 25-hydroxyvitamin D (25(OH)D) and SPL.

SEARCH STRATEGY: Embase, PubMed, and Web of Science were searched for relevant papers published before February 20, 2016, using search terms including "vitamin D" and "pregnancy loss."

SELECTION CRITERIA: Case-control and cohort studies investigating the relationship of maternal serum 25(OH)D and SPL were included.

DATA COLLECTION AND ANALYSIS: Two authors independently extracted original data from the selected papers. The DerSimonian-Laird random-effects model was used to perform the meta-analysis. Heterogeneity was assessed by calculating I2 .

MAIN RESULTS: Five studies, including 10 630 pregnant women, met the inclusion criteria. There was no significant association between a low 25(OH)D level and an increased risk of SPL.

In a subgroup analysis, an extremely low 25(OH)D level (<20 ng/mL) was significantly associated with an increased risk of SPL in the first trimester (relative risk 2.24 , 95% confidence interval 1.15-4.37); the heterogeneity across studies was not significant (I2 =0.0%, P=0.355).

CONCLUSIONS: Severe Vitamin D deficiency could be detrimental to early embryonic development and increase the risk of early SPL

Tags: Meta-analysis Pregnancy