Beckwith–Wiedemann syndrome (; abbreviated BWS) is an overgrowth disorder usually present at birth, characterized by an increased risk of childhood cancer and certain congenital features. A minority (<15%) cases of BWS are familial, meaning that a close relative may also have BWS, and parents of an affected child may be at increased risk of having other children with BWS. While children with BWS are at increased risk of childhood cancer, most children with BWS do not develop cancer and the vast majority of children who do develop cancer can be treated successfully. Presentation
No consensus clinical diagnostic criteria for Beckwith–Wiedemann syndrome (BWS) exist. Beckwith–Wiedemann syndrome (BWS) should be suspected in individuals who have one or more of the following major and/or minor findings.Major findings associated with BWS
Macrosomia (traditionally defined as weight and length/height >97th centile)
Macroglossia
Hemihyperplasia (asymmetric overgrowth of one or more regions of the body)
Omphalocele (also called exomphalos) or umbilical hernia
Embryonal tumor (e.g., Wilms tumor, hepatoblastoma, neuroblastoma, rhabdomyosarcoma) in childhood
Visceromegaly involving one or more intra-abdominal organs including liver, spleen, kidneys, adrenal glands, and/or pancreas
Cytomegaly of the fetal adrenal cortex (pathognomonic)
Renal abnormalities including structural abnormalities, nephromegaly, nephrocalcinosis, and/or later development of medullary sponge kidney
Anterior linear ear lobe creases and/or posterior helical ear pits
Placental mesenchymal dysplasia
Cleft palate (rare in BWS)
Cardiomyopathy (rare in BWS)
Positive family history (≥1 family members with a clinical diagnosis of BWS or a history or features suggestive of BWS)Minor findings associated with BWS

Pregnancy-related findings including polyhydramnios and prematurity in fetuses with the condition.
While they are at increased risk of childhood cancer, most of them do not develop the disease, and the vast majority of the children who do can be treated successfully.Children with BWS for the most part had no significant delays when compared to their siblings. However, some of them do have speech problems that could be related to macroglossia or hearing loss.Advances in treating neonatal complications and premature infants in the last twenty years have significantly improved the true infant mortality rate associated with BWS. In a review of pregnancies that resulted in 304 children with BWS, no neonatal deaths were reported. This is compared to a previously reported mortality rate of 20%. The data from the former study was derived from a BWS registry, a database that may be slightly biased towards involving living children; however, death was not an exclusion criterion to join the registry. This suggests that while infants with BWS are likely to have a higher than normal infant mortality risk, it may not be as high as 20%. Assisted reproductive technology
Assisted reproductive technology (ART) is a general term referring to methods used to achieve pregnancy by artificial or partially artificial means. According to the CDC, in general, ART procedures involve surgically removing eggs from a womans ovaries, combining them with sperm in the laboratory, and returning them to the womans body or donating them to another woman. ART has been associated with epigenetic syndromes, specifically BWS and Angelman syndrome.