No yolk sac seen after 50 days of amenorrhea

Amenorrhea is a typical feature of pregnancy. Even if the pregnancy is successful, you still need to go to the hospital for further examination to see the development of the gestational sac. Abnormalities are likely to occur at this time. The absence of yolk sac after 50 days of amenorrhea will definitely make many pregnant women very nervous. There are many factors that lead to this situation. Since you have just become pregnant, you need to pay close attention.

Around 50 days is the early stage of pregnancy. In this case, if you want to have a child, you can continue the pregnancy, but you must pay attention to regular check-ups. Due to the short pregnancy period, it is normal if the fetal heart, embryo and yolk sac are not found. The appearance of fetal heartbeat and fetal bud within ten weeks is a normal phenomenon, so there is no need to worry too much for the time being. You can focus on observation and no treatment is available for the time being.

In another case, if your menstruation is abnormal and there is bleeding at this time, you should pay special attention, because this may be a sign of threatened abortion, so you should check it in time, find out the cause, and then treat it symptomatically. Generally, if you are sure to be pregnant in the early stages of pregnancy, you need to do a routine check to check whether it is an empty gestational sac. If there is still no yolk sac after observing for a period of time, you may be recommended to do a curettage.

How long does it take for the yolk sac to appear?

Before the embryo matures, the yolk nest supplies nutrients to the oocyst and is the transport system between the embryo and the mother, with functions such as nutrition, hematopoiesis, metabolism and immunology. At the fifth week of pregnancy, the yolk nest will separate from the primitive intestine and gradually degenerate. By the 7th week, it has become a small sac with a diameter of less than 5 mm, existing on the surface of the embryo. This is also a phenomenon that occurs in repetitive systems.

Generally speaking, the gestational sac and yolk nest can be detected on the 35th day of pregnancy. The embryo is formed in 40-50 days. The embryonic heart appears in 50-60 days. If the normal menstruation is delayed, it may be due to delayed ovulation, which means that the appearance of the yolk nest, germ and embryonic core will also be delayed. If the menstrual cycle is 28 days, ovulation usually occurs on the 14th day of menstruation. If calculated based on 35 days, then ovulation occurs around the 20th day of menstruation.

Function of yolk sac

The yolk sac is because after the embryo is folded, the archenteron will be divided into two parts: the archenteron inside the embryo and the yolk sac outside the embryo. There is a large amount of yolk in the yolk sac, and the extraembryonic endoderm and extraembryonic mesoderm form the wall of the yolk nest. Generally speaking, seeing the yolk sac means that the embryo is normal. But later the yolk nest will gradually disappear.

It is normal for a yolk nest to appear in the gestational sac; otherwise, the pregnancy may be terminated if there is no yolk nest. For example, having a yolk nest is like a house waiting for people to move in. As mentioned above, the yolk nest appears about thirty-five days after pregnancy, and the embryonic heart appears 1-2 weeks after the yolk nest. Both are observed through B-ultrasound. Under normal circumstances, ordinary instruments can also be used for examination.