How to determine baby\’s gender early in pregnancy? Pregnancy is a very important process for every woman. Babies with certain medical conditions have different genders early in pregnancy. So after receiving this news from the screening, many expectant mothers may be wondering how to know the gender of their baby? Here, we answer your questions for you. 1. Amniocentesis Amniocentesis is a method to determine the gender of the baby in early pregnancy. It is the process of obtaining fetal cells by taking a sample of amniotic fluid. Fetal DNA is often mixed in amniotic fluid, so amniocentesis can accurately measure fetal sex.