Abnormal Maternal Levels of Serum B12 Are Associated with Preeclampsia: A Systematic Review and Meta-Analysis Level of serum B12 is associated with preeclampsia

Context: Some evidence highlights that there is a relationship between maternal vitamin B12 levels and the development of preeclampsia (PE) in pregnant women. However, the relationship between PE and vitamin B12 is not clear. Objective: The aim of this study was to investigate vitamin B12 levels in PE in comparison to normotensive pregnant women. Data Sources: PubMed-MEDLINE, Scopus and Web of Science were searched, along with the reference lists of included articles, up to August 2019. Study Selection: The literature was searched for observational studies that investigated vitamin B12 levels in PE. Data Extraction: Data were extracted independently by two researchers. Data were pooled using a random-effects model. Results: Our findings showed that B12 vitamin levels were significantly lower in women with PE versus healthy women (-15.24 pg/ml (95% CI: -27.52, -2.954; P < 0.015)). However, there was a high heterogeneity between the assessed studies (I2 = 97.8%, P =0.0103). The subgroup analysis, based on folic acid supplementation, homocysteine concentrations and gestational age at the time of vitamin B12 sampling, did not find the sources of heterogeneity. Conclusions: We found that women with PE had significantly lower vitamin B12 concentrations versus normotensive pregnant women.

Keywords:

Preeclampsia , Vitamin B12 , Pregnancy , Observational studies