The accuracy of ultrasound examination of pregnancy needs to be analyzed according to different situations. The embryo development in pre-pregnancy is small, and the obvious fetal sac may not be visible through ultrasound too early, so the accuracy of ultrasound examination in early pregnancy is lower. While ultrasound examination in the sixth week of pregnancy, visible gestational sac and primitive heart tube pulsation, can determine whether the fetus is intrauterine pregnancy, at this time the ultrasound examination accuracy rate is higher. Therefore, perfect ultrasound examination during pregnancy is conducive to timely grasp the status of fetal development, and 3-4 times of ultrasound is needed during the whole pregnancy. The 1st ultrasound at 12-16 weeks of pregnancy can determine the development of the embryo, the 2nd ultrasound at 20-24 weeks of pregnancy can identify whether the fetus is malformed or not, and the ultrasound at 37-40 weeks of pregnancy can help pregnant women to understand the position of the fetus, the size of the fetus, the maturity of the placenta, and whether there is any umbilical cord around the neck and so on, so as to prepare for the approaching labor and delivery in a variety of ways. The earliest way to determine whether a woman is pregnant or not is a pregnancy test, that is, when a woman is pregnant, the fertilized egg moves to the uterine cavity and deposits, forming an embryo, and the placental syncytiotrophoblast cells produce a large amount of human chorionic gonadotropin, which can be detected in a woman’s blood to confirm whether she is pregnant or not, and ultrasonography can be performed after the initial clarification of one week to confirm the pregnancy.