First-Trimester Screening for Chromosomal Conditions in Multiple Pregnancies

During your first trimester (11 to 13 weeks + 6 days), I offer a comprehensive screening to estimate the risk of your babies having common chromosomal conditions, including Down syndrome (Trisomy 21), Trisomy 18, and Trisomy 13. This combined screening includes your age, a simple blood test that measures pregnancy-related proteins, and a detailed ultrasound to measure your babies’ nuchal translucency. This approach detects about 90% of pregnancies affected by Down syndrome, providing valuable information early in your pregnancy.

I’ll also interpret your results based on the type of multiple pregnancy you have. If you’re carrying dichorionic twins, I’ll calculate an individual risk for each baby because each fetus may have a different nuchal translucency measurement. If you have monochorionic twins, both babies will share the same estimated risk because they share one placenta. For triplet pregnancies, screening is based on your age and the ultrasound measurement of nuchal translucency. Throughout this process, I’ll explain every result clearly, answer your questions, and help you make informed decisions so you feel supported and confident every step of the way.