Whether the gestational sac can be seen on the 37th day of pregnancy by ultrasound needs to be combined with the woman’s menstrual cycle to make a comprehensive judgment, there may be the following cases: 1. If a rhythmic fetal heartbeat and embryonic buds are seen in the gestational sac, the diagnosis of early pregnancy and live fetus can be confirmed. 2.Can’t be seen: If a woman has irregular menstruation, late ovulation or polycystic ovaries, she may have a late fertilization of the egg and therefore the gestational sac may not be seen during the ultrasound on day 37 of pregnancy. It is recommended to review the ultrasound at 50 days of pregnancy. If the gestational sac can be detected in the uterus at the time of review, and the fetal heart and germ are present, intrauterine pregnancy can be diagnosed. If the gestational sac cannot be detected in the uterus at the time of follow-up, an ectopic pregnancy should be considered. In order to promote the growth and development of the embryo, pregnant women should pay attention to folic acid supplementation in early pregnancy to prevent fetal neural tube malformation. It is advisable to eat foods rich in high quality protein and nutrients to promote the growth and development of the fetus.