Vitamin B12 among parturients and their newborns and its relationship with birthweight

• Published in: European journal of obstetrics & gynecology and reproductive biology Vol. 45; no. 3; pp. 155 - 163
• Main Authors: Fréry, N., Huel, G., Leroy, M., Moreau, T., Savard, R., Blot, P., Lellouch, J.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 24.07.1992; Elsevier
• Subjects: Adult; African Americans; Biological and medical sciences; Birth Weight; Birthweight; Cobalamin; Ethnic Groups; Female; Fetal Blood - metabolism; Gestational Age; Gynecology. Andrology. Obstetrics; Humans; Infant, Newborn; Male; Management. Prenatal diagnosis; Maternal Age; Medical sciences; Pregnancy; Pregnancy. Fetus. Placenta; Smoking; Tobacco smoking; Vitamin B 12 - blood; Vitamin B 12 Deficiency - blood; Vitamin B12; Pregnancy; Cobalamin; Vitamin B12; Birthweight; Tobacco smoking; Human; Newborn; Mother; Cobalamine; Birth weight; Nutritional status
• ISSN: 0301-2115; 1872-7654
• DOI: 10.1016/0028-2243(92)90076-B

Vitamin B12 (Cobalamin) is an essential nutrient in the diet of humans, particularly during pregnancy, nevertheless very few epidemiological studies have been reported, particularly concerning variation factors. The purpose of this study is to assess the role of vitamin B12 on birthweight after taking into account potential confounders, such as obstetrical, socioeconomic, and biological factors which will be identified. This study was conducted on 188 single births occurring during a 5-month period in an obstetrical care unit in Paris. Vitamin B12 plasma levels and folate plasma levels of mothers and cords along with haematological parameters were measured. Social and obstetrical features of the mothers as well as their tobacco exposure and alcohol consumption were recorded. Cord blood vitamin B12 levels were highly correlated with maternal levels ( r = 0.63, P < 0.001) and were 2–3-fold higher. Three variation factors of vitamin B12 were identified: maternal age, ethnicity and tobacco exposure. Negative correlations between birthweight and vitamin B12 levels were observed only among the smoker group ( r mothers = −0.46, P < 0.05 and r cords = −0.42, P < 0.05). After adjustment for ethnicity and parity, birthweight remained negatively linked to vitamin B12 in smokers. This relationship could suggest that the availability of vitamin B12 for fetal development depends on certain biological factors present only in mothers who smoked. We hypothesized this relationship could be explained, in part, by lipid metabolism, particular to smokers.