IVF ultrasound gestational sac is around 10mm, but there is an error, everyone’s physique is different, the size of the gestational sac development will also have an error. Through the ultrasound examination, the development of the embryo is normal, you can rest assured, test tube ultrasound time is about 28 days after the transplantation, the ultrasound examination is mainly to see whether the intrauterine pregnancy, whether the gestational sac of fetal heart, fetal buds. If there is a fetal heart and buds through the examination, the development of the gestational sac is normal, regular checkups can be, if the ultrasound does not appear fetal heart, buds, it is best to check again in a week, if it still does not appear, the embryo is considered to be embryonic underdevelopment, you need to go to the hospital for abortion. After doing IVF, you need to take regular blood tests for progesterone, so as not to cause miscarriage easily with low progesterone in the body, if the progesterone is low, it is best to take progesterone treatment.