The Impact of Third Trimester Maternal Serum Vitamin B12 and Folate Status on Fetal Birth Weight. Is Maternal Serum Homocysteine a Predictor of Low Birth Weight Infants?

Abstract

Objective: The aim of this study is to evaluate vitamin B12, folate, and homocysteine status in pregnant women in the third trimester of pregnancy and their relationship to fetal birth weight and their correlation to corresponding neonatal cord blood levels, and in addition, to evaluate the possibility of maternal serum homocysteine level as a predictor of low birth weight infants. Subjects and Methods: In this cross-sectional study, a total of two hundred pregnant women in third trimester (≥28 weeks) were recruited. After a detailed obstetrical and medical history, and clinical assessment, participants were subdivided into two groups: Group (A)-pregnant women who delivered average birth weight (ABW) infants and Group (B) for those who delivered low birth weight (LBW) infants between completed 37 and 42 weeks. Results: Vitamin B12 deficiency was observed in 24.1% of the total cohort. The mean vitamin B12 level was significantly lower in group (B) compared to group (A) (195.2 ± 38.9 vs. 225.9 ± 66.59 respectively P = 0.008). The mean level of homocysteine for women in group (B) was significantly higher than those determined from women in group (A) (9.10 ± 5.9 vs. 7.6 ± 3.83 respectively, P = 0.042). On the other hand, the mean folate levels showed statistically insignificant differences between both groups. The mean cord vitamin B12 level was significantly lower in LBW infants in comparison to ABW infants (277 ± 61.93 vs. 312.03 ± 81.87 respectively, P = 0.015), while the mean level of cord homocysteine for LBW infants was significantly higher than those levels determined from ABW infants (7.9 ± 3.79 vs. 6.6 ± 2.09 respec- deficiency could be significant risk for LBW infants. Hyperhomocysteinemia has been shown to be a predictor for adverse pregnancy outcomes particularly LBW.

Maternal vitamin B12 deficiency and perinatal outcomes in southern India

“…In the current study, neonatal vitamin B 12 concentrations were 1.3-fold higher than maternal vitamin B 12 concentrations early in pregnancy. Findings are consistent with previous studies that reported higher vitamin B 12 concentrations in infants compared to mothers, ranging from 13 to 43% at mid-gestation [ 23 , 42 , 44 , 46 , 87 , 88 ] or delivery [ 31 – 40 , 43 , 45 , 89 ] to two-fold higher than maternal vitamin B 12 concentrations at delivery [ 35 , 36 , 43 , 45 ].…”

“…For example, neonates born to women who had vitamin B 12 deficiency at enrollment had a 2-fold greater risk of vitamin B 12 deficiency at birth. Findings are consistent with studies of the associations of maternal vitamin B 12 concentrations during gestation [ 23 , 42 , 44 , 87 , 88 ] and at delivery [ 31 – 38 , 40 , 43 , 45 , 89 ] with neonatal vitamin B 12 levels at birth and in the first six weeks of life.…”

“…In this study, maternal vitamin B 12 status was not associated with other neonatal outcomes, including WHO z-scores, ponderal index, mid-upper arm circumference, or head circumference. Although few studies have evaluated the association of vitamin B 12 status during pregnancy and infant anthropometric outcomes, most studies to date have focused on neonatal head circumference, and findings have been heterogenous [ 61 , 88 , 99 , 102 ]. Findings regarding the association of maternal vitamin B 12 status with other infant health outcomes have been divergent.…”

Trends of folate, vitamin B12, and homocysteine levels in different trimesters of pregnancy and pregnancy outcomes

“…Although the relationship between vitamin B 12 levels and birth weight is controversial, present study revealed significant association of first and second trimesters vitamin B 12 deficiency with LBW. Vitamin B 12 deficiency has been associated with LBW and intrauterine growth restriction (Rogne et al, ; Youssry, Radwan, Gebreel, & Patel, ; Ahmed, Akhter, Sharmin, Ara, & Hoque, ); however, a few studies did not find any association (Oztürk, Keskin, Tas, Akgün, & Avflar, ; Abraham, Mathews, Sebastian, Chacko, & Sam, . There is a need to improve the vitamin B 12 status among pregnant women as impaired status of maternal vitamin B 12 throughout pregnancy is a predictor for a high‐risk vitamin B 12 deficiency in infants (Finkelstein et al, ).…”

Vitamin B12 and Folic Acid Status Among Displaced Pregnant Women Attending Antenatal Care Clinic in Domiz Camp of a Syrian Refugees /Kurdistan Region, Iraq

“…It was hypothesized that B12 and folic acid levels in pregnant women might be low due to pregnancy and socio-economic status. Nutritional deficiencies of micronutrients are prevalent among pregnant women in most developing countries (Youssry et al, 2017).…”