title: Nitrosatable drug exposure during early pregnancy and neural tube defects in offspring: National Birth Defects Prevention Study.
abstract: Nitrosatable drugs, such as secondary or tertiary amines and amides, form N-nitroso compounds in the presence of nitrite. Various N-nitroso compounds have been associated with neural tube defects in animal models. Using data from the National Birth Defects Prevention Study, the authors examined nitrosatable drug exposure 1 month before and 1 month after conception in 1,223 case mothers with neural tube defect-affected pregnancies and 6,807 control mothers who delivered babies without major congenital anomalies from 1997 to 2005. Nitrite intakes were estimated from mothers' responses to a food frequency questionnaire. After adjustment for maternal race/ethnicity, educational level, and folic acid supplementation, case women were more likely than were control women to have taken tertiary amines (odds ratio = 1.60, 95% confidence interval (CI): 1.31, 1.95). This association was strongest with anencephalic births (odds ratio = 1.96, 95% CI: 1.40, 2.73); odds ratios associated with tertiary amines from the lowest tertile of nitrite intake to the highest tertile were 1.16 (95% CI: 0.59, 2.29), 2.19 (95% CI: 1.25, 3.86), and 2.51 (95% CI: 1.45, 4.37), respectively. Odds ratios for anencephaly with nitrosatable drug exposure were reduced among women who also took daily vitamin supplements that contained vitamin C. Prenatal exposure to nitrosatable drugs may increase the risk of neural tube defects, especially in conjunction with a mother's higher dietary intake of nitrites, but vitamin C might modulate this association.
authors: School of Rural Public Health, Texas A&M Health Science Center, College Station, USA. jdbrender@srph.tamhsc.edu
authors: Jean D
authors: JD
authors: Brender
authors: Martha M
authors: MM
authors: Werler
authors: Katherine E
authors: KE
authors: Kelley
authors: Ann M
authors: AM
authors: Vuong
authors: Mayura U
authors: MU
authors: Shinde
authors: Qi
authors: Q
authors: Zheng
authors: John C
authors: JC
authors: Huber
authors: Joseph R
authors: JR
authors: Sharkey
authors: John S
authors: JS
authors: Griesenbeck
authors: Paul A
authors: PA
authors: Romitti
authors: Peter H
authors: PH
authors: Langlois
authors: Lucina
authors: L
authors: Suarez
authors: Mark A
authors: MA
authors: Canfield
mesh_terms: D000577:Amides / Q000009:adverse effects* / Q000378:metabolism; D000588:Amines / Q000009:adverse effects* / Q000378:metabolism; D001205:Ascorbic Acid / Q000008:administration & dosage; D016022:Case-Control Studies; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D009436:Neural Tube Defects / Q000139:chemically induced* / Q000517:prevention & control; D009573:Nitrites / Q000378:metabolism; D009603:Nitroso Compounds / Q000378:metabolism / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced*
chemical_list: D000577:Amides; D000588:Amines; D009573:Nitrites; D009603:Nitroso Compounds; D001205:Ascorbic Acid