Aylin Yetim1, Erhan Aygün2, Çağcıl Yetim3, Ahmet Ucar4, Zeynep Karakaş5, Gülden Gökçay6, Mübeccel Demirkol6, Beyhan Ömer7, Gülbin Gökçay8, Firdevs Baş9, Ethem Erginöz10, Türkan Dağoğlu2. 1. Department of Pediatrics, Istanbul School of Medicine, Istanbul University, Fatih, Turkey. 2. Division of Neonatology, Department of Pediatrics, Istanbul School of Medicine, Istanbul University, Fatih, Turkey. 3. Department of Gynecology and Obstetrics, Istinye University, Istanbul, Turkey. 4. Department of Pediatric Endocrinology and Diabetes, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey. 5. Department of Pediatric Hematology and Oncology, Istanbul University, Fatih, Turkey. 6. Department of Pediatric Nutrition and Metabolism, Istanbul School of Medicine, Istanbul University, Fatih, Turkey. 7. Department of Biochemistry, Istanbul School of Medicine, Istanbul University, Fatih, Turkey. 8. Child Health Institute, Istanbul University, Fatih, Turkey. 9. Department of Pediatric Endocrinology and Diabetes, Istanbul School of Medicine, Istanbul University, Fatih, Turkey. 10. Department of Public Health, Faculty of Medicine, Cerrahpaşa School of Medicine, Istanbul University Cerrahpasa, Istanbul, Turkey.
Abstract
OBJECTIVE: Our aim was to determine the prevalence of maternal and neonatal vitamin B12 (vit-B12) and folate deficiencies, a new cutoff value of serum vit-B12 in newborns using vit-B12-related metabolites and also cutoff values of homocysteine (Hcy), propionyl (C3) carnitine, and methyl malonic acid (MMA) in newborns using a vit-B12 cutoff value of 200 pg/mL. METHODS: Healthy pregnant women (without iron deficiency) and 98 healthy, term, singleton babies were included. Blood samples were obtained from women 0-8 h before birth and from cord blood during birth for hemogram and to measure serum vit-B12, folate, and Hcy levels. Maternal and cord blood serum vit-B12 levels were classified as low < 200 pg/mL, marginal 200-300 pg/mL, and normal ≥ 300 pg/mL. Neonatal urine MMA levels were analyzed in mothers with a vit-B12 concentration < 300 pg/mL. C3 carnitine levels of newborns were acquired from extended newborn screening. Receiver operating characteristics curve (ROC) analysis was used for serum vit-B12, urine MMA, C3 carnitine, and Hcy. RESULTS: Of total, 98 pregnant women (28.6 ± 5.5-year-old) and 98 newborn were included. Vit-B12 level was lower than 300 pg/mL in 93% of the pregnant women and 61% of cord blood samples. Folate deficiency was not found in either group. There was statistically significant negative correlation between baby C3 carnitine, cord blood folate (r = -0.265, p = .008) and cord blood vit-B12 (r = -0.220, p = .029). In backward stepwise linear regression analysis, maternal vit-B12 level exerted the most marked effect on cord blood vit-B12 level (adjusted R2 = 0.457). In ROC analysis, the Hcy cutoff value was 4.77 µmol/L (68.4% sensitivity, 58.3% specificity, p = .012) for the detection of vit-B12 deficiency. CONCLUSION: Vit-B12 deficiency remains an important health issue for pregnant women and newborns. Our study revealed a cutoff value for Hcy for the detection of nutritional vit-B12 deficiency that could be used in practice for newborns.
OBJECTIVE: Our aim was to determine the prevalence of maternal and neonatal vitamin B12 (vit-B12) and folate deficiencies, a new cutoff value of serum vit-B12 in newborns using vit-B12-related metabolites and also cutoff values of homocysteine (Hcy), propionyl (C3) carnitine, and methyl malonic acid (MMA) in newborns using a vit-B12 cutoff value of 200 pg/mL. METHODS: Healthy pregnant women (without iron deficiency) and 98 healthy, term, singleton babies were included. Blood samples were obtained from women 0-8 h before birth and from cord blood during birth for hemogram and to measure serum vit-B12, folate, and Hcy levels. Maternal and cord blood serum vit-B12 levels were classified as low < 200 pg/mL, marginal 200-300 pg/mL, and normal ≥ 300 pg/mL. Neonatal urine MMA levels were analyzed in mothers with a vit-B12 concentration < 300 pg/mL. C3 carnitine levels of newborns were acquired from extended newborn screening. Receiver operating characteristics curve (ROC) analysis was used for serum vit-B12, urine MMA, C3 carnitine, and Hcy. RESULTS: Of total, 98 pregnant women (28.6 ± 5.5-year-old) and 98 newborn were included. Vit-B12 level was lower than 300 pg/mL in 93% of the pregnant women and 61% of cord blood samples. Folate deficiency was not found in either group. There was statistically significant negative correlation between baby C3 carnitine, cord blood folate (r = -0.265, p = .008) and cord blood vit-B12 (r = -0.220, p = .029). In backward stepwise linear regression analysis, maternal vit-B12 level exerted the most marked effect on cord blood vit-B12 level (adjusted R2 = 0.457). In ROC analysis, the Hcy cutoff value was 4.77 µmol/L (68.4% sensitivity, 58.3% specificity, p = .012) for the detection of vit-B12 deficiency. CONCLUSION: Vit-B12 deficiency remains an important health issue for pregnant women and newborns. Our study revealed a cutoff value for Hcy for the detection of nutritional vit-B12 deficiency that could be used in practice for newborns.