Background: The association between maternal and cord blood zinc level and pregnancy outcomes remains uncertain. The present study aims to assess whether maternal blood zinc level represents cord blood zinc level correctly.

Methods: In this meta-analysis, systematic search was performed in PubMed, Web of Science, and Scopus databases for relevant available English articles which included mean and standard deviation values of cord blood zinc level up to April 2019. For the assessment of the relation between cord blood zinc level and pregnancy outcomes, the pooled standard mean difference with 95% confidence interval (CI) was used and 23 studies were analyzed.

Results: Cumulative analysis showed that cord blood zinc level was found significantly decreased in pregnancies with complications compared with healthy pregnancy controls [REM: P = 0.0007, mean difference -7.9 (-12.48, -3.31)]. For further analysis, maternal serum zinc level status was determined from same studies to compare with cord blood levels and subgroups were detected as “Preterm”, “Preeclampsia”, “Small for gestational age/Intrauterine growth restriction and Low birth weight”. It was observed that cord blood zinc levels in subgroup analysis were also decreased and/or tend to be decreased compared to healthy pregnancies, except for preeclampsia subgroup. Also, a correlation was seen between cord blood and maternal blood zinc level status (R = 0.4365, 95% CI -0.530, 0.756; P = 0.0351).