Birth defects, also named congenital anomalies, or rare disease (when a birth defect is very rare), are structural or functional anomalies, that occur during intrauterine life and can be identified prenatally, at birth, or later in infancy. Examples of structural defects (congenital malformations) are: congenital heart defects, spina bifida, cleft lip or palate, limb deficiency, hypospadias, club foot, Down syndrome, congenital rubella syndrome, congenital Zika syndrome, fetal alcohol syndrome. Examples of functional defects are:  metabolic diseases, hypothyroidism, congenital adrenal hyperplasia, thalassemia, sickle cell disease, cystic fibrosis, cerebral palsy, muscular distrophy, deafness, autism, ADHD.

See factsheets in the following links

https://www.cdc.gov/ncbddd/index.html

https://www.cdc.gov/ncbddd/birthdefects/types.html https://www.marchofdimes.org/complications/birth-defects-and-health-conditions.aspx