Genetic Screening and the Obese Gravida

Obesity compromises all forms of genetic screening. Although the risk for fetal aneuploidy is not altered by obesity, the risk for significant birth defects is increased. Therefore, the obese gravida is at an increased risk of fetal malformations with a diminished ability to be screened effectively by all screening methods: ultrasound, traditional serum analyte screening, and cell-free DNA screening. This chapter outlines both the current options and limitations of screening in the obese gravida. The offering of screening and diagnostic testing should not be altered in obese women despite the compromises placed on accurate fetal assessment.