Can all birth defects be detected through first-trimester risk assessment?
No. Currently only Down syndrome and trisomy 18 can be detected by screening through measurements of proteins in the mother’s blood and nuchal translucency. If the fetus’s NT measurement is greater than 3 mm, which occurs in fewer than 1-in-20 women (5%) there may be an increased risk of some types of birth defects. We will discuss that with you if we find that. First-trimester risk assessment does not substitute for a careful examination of your baby with ultrasound later in pregnancy to check for structural problems.
