Epidemiology
Spina bifida is one of the most common birth defects, with an average worldwide incidence of one to two cases per 1000 births, but certain populations have a significantly greater risk.
In the United States, the average incidence is 0.7 per 1000 live births. The incidence is higher on the East Coast than on the West Coast, and higher in white people (one case per 1000 live births) than in black people (0.1–0.4 case per 1000 live births). Immigrants from Ireland have a higher incidence of spina bifida than do natives. Highest rates of the defect in the USA can be found in Hispanic youth.
The highest incidence rates worldwide were found in Ireland and Wales, where three to four cases of myelomeningocele per 1000 population have been reported during the 1970s, along with more than six cases of anencephaly (both live births and stillbirths) per 1000 population. The reported overall incidence of myelomeningocele in the British Isles was 2.0–3.5 cases per 1000 births. Since then, the rate has fallen dramatically with 0.15 per 1000 live births reported in 1998, though this decline is partially accounted for because some fetuses are aborted when tests show signs of spina bifida (see Pregnancy screening above).
Parents of children with spina bifida have an increased risk of having a second child with a neural tube defect.
This condition is more likely to appear in females; the cause for this is unknown.
Read more about this topic: MOMS Study