Nutritional Factors and Hypospadias Risks

Abstract

SUMMARY We examined whether hypospadias was associated with several aspects of the diet, including intake of animal products, intake of several nutrients and food groups related to a vegetarian diet and estrogen metabolism, and diet quality. The study included deliveries from 1997 to 2005 that were part of the National Birth Defects Prevention Study. Diet was assessed by food frequency questionnaire during maternal telephone interviews, and two diet quality indices were developed based on existing indices. Analyses included 1,250 cases with second or third degree hypospadias (urethra opened at the penile shaft, scrotum or perineum) and 3,118 male, liveborn, non-malformed controls. All odds ratios (ORs) and 95% confidence intervals (CI) were estimated from logistic regression models that included several potential confounders, including energy intake. Intake of animal products was not associated with hypospadias; e.g., the adjusted OR for any versus no intake of meat was 1.0 (95% CI 0.6, 1.6). Frequency of intake of meat or other animal products was also not associated with hypospadias, nor was intake of iron or several nutrients that are potentially related to estrogen metabolism. Diet quality was also not associated with hypospadias; the ORs for diet quality in the highest versus lowest quartile for the two diet quality indices were 1.0 (95% CI 0.6, 1.6) and 0.9 (95% CI 0.7, 1.1). In conclusion, this large study does not support an association of a vegetarian diet or worse diet quality with hypospadias.

Lower rate of selected congenital heart defects with better maternal diet quality: a population-based study

“…Some studies examined a priori diet quality indices in relation to the risk of birth defects,13 14 24 but not of CHDs. The studies that used the DQI-P and MDS reported associations between increasing diet quality and reduced risk for some birth defects (neural tube defects and orofacial clefts13), but not others (microtia and hypospadias) 14 24. The magnitude of the risk reduction for CHDs in this study (table 2) is approximately similar, if slightly weaker, to that observed for neural tube defects and orofacial clefts with similar dietary indices 13.…”

“…Dietary approaches have only recently been applied to birth defect risk, and scarce population-based data are available. Recently, investigators from the National Birth Defects Prevention Study (NBDPS) have reported reduced risk for some birth defects (neural tube defects and orofacial clefts)13 but not others (hypospadias)14 with better maternal diet quality, as estimated by the Mediterranean Diet Score (MDS) and the Diet Quality Index for Pregnancy (DQI-P). Here we expand this dietary pattern approach to major non-syndromic CHDs.…”

Maternal intake of vitamin E and birth defects, national birth defects prevention study, 1997 to 2005

“…The associations observed for birth defects other than CHDs, anorectal atresia and hypospadias, were unexpected, and warrant further analysis and replication in other study populations. A recent study of nutrient intake and hypospadias in the NBDPS found no association with dietary intake of vitamin C, an antioxidant vitamin, but vitamin E was not investigated (Carmichael et al, ).…”

Hypospadias: One Defect, Multiple Causes, Acting Through Shared Pathways

“…Various nutritional risk factors have been suggested for hypospadias, including vegetarian diet, iron supplements, nutrients related to estrogen metabolism, and low quality diet [41,[63][64][65]. Carmichael et al (2012) evaluated these factors, but evidence was not supportive of associations with moderate to severe hypospadias [65].…”

“…Various nutritional risk factors have been suggested for hypospadias, including vegetarian diet, iron supplements, nutrients related to estrogen metabolism, and low quality diet [41,[63][64][65]. Carmichael et al (2012) evaluated these factors, but evidence was not supportive of associations with moderate to severe hypospadias [65]. In contrast, in another study from the same group, maternal intake of certain phytoestrogens, i.e., plant-derived substances with estrogenic properties, and total phytoestrogen intake was negatively associated with moderate to severe hypospadias risk [66].…”