The National Birth Defects Prevention Study recently reported that mothers of children with birth defects are more likely to be obese than mothers of healthy children. Obese mothers are more likely to have children with birth defects by 1.33 to 2.10 ratio. Birth defects associated with obese mothers are spina bifida, heart defects, hypospadia (abnormal opening of the tip of the penis) , anorectal atricia (abnromality of the anus and rectum) , limb reduction defects, diaphragmatic hernia (protrosion of intestinal parts through the diaphragm towards the lungs) , and omphalocele (when the contents of the abdomen, usually the intestine protrudes through the navel) . Some experts speculated that the cause may be undiagnosed diabetes in obese mothers.