Multicentre study of maternal and neonatal outcomes in individuals with Prader-Willi syndrome

J Med Genet. 2018 Sep;55(9):594-598. doi: 10.1136/jmedgenet-2017-105118. Epub 2018 May 18.


Introduction: Prader-Willi syndrome (PWS) is a complex genetic disorder associated with three different genetic subtypes: deletion of the paternal copy of 15q11-q13, maternal UPD for chromosome 15 and imprinting defect. Patients are typically diagnosed because of neonatal hypotonia, dysmorphism and feeding difficulties; however, data on the prenatal features of PWS are limited.

Objective: The aim of the study was to identify and compare frequencies of prenatal and neonatal clinical features of PWS among the three genetic subtypes.

Methods: Data from 355 patients with PWS from the Rare Diseases Clinical Research Network PWS registry were used to analyse multiple maternal and neonatal factors collected during an 8-year multisite study.

Results: Among our cohort of 355 patients with PWS (61% deletion, 36% UPD and 3% imprinting defect) 54% were born by caesarean section, 26% were born prematurely and 34% with a low birth weight (frequencies 32%, 9.6% and 8.1%, respectively, in the general population). Fetal movements were reported as decreased in 72%. All babies were hypotonic, and 99% had feeding difficulties. Low Apgar scores (<7) were noted in 17.7% and 5.6% of patients, respectively, compared with 1% and 1.4%, respectively, in the general population. Maternal age and pre-pregnancy weight were significantly higher in the UPD group (p=0.01 and <0.001, respectively).

Conclusion: We found a higher rate of perinatal complications in PWS syndrome compared with the general population. No significant differences in the genetic subtypes were noted except for a higher maternal age and pre-pregnancy weight in the UPD subgroup.

Keywords: deletion; neonatal features; perinatal features; prader- willi syndrome; uniparental disomy.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Apgar Score*
  • Body Weight
  • Cesarean Section
  • Female
  • Humans
  • Infant, Newborn
  • Infant, Premature
  • Prader-Willi Syndrome / diagnosis
  • Prader-Willi Syndrome / pathology*
  • Pregnancy
  • Pregnancy Outcome
  • Prognosis