Can one embryo be twins?

The embryonic bud is very important for both pregnant women and fetuses. The embryo bud will form between 40 and 50 days of pregnancy, and its size will increase as the pregnancy progresses. Many people want to know whether a fetus can lead to twins. Actually, it is not, because a embryo bud means that you are pregnant with a child. Below, we will introduce you to the relevant knowledge about embryo buds in detail!

1. What is embryo bud?

The embryonic bud refers to the first two weeks of development of the fertilized egg. Later, various organs gradually form in the embryo before 8 weeks of pregnancy. The period from the third trimester to the first month and four weeks of pregnancy is called the embryonic stage.

2. Time of embryo formation

Because the development of the embryo is normal, the gestational sac is formed in 30-40 days, the fetal bud is formed in 40-50 days, and the fetal heart is formed in 50-60 days. Therefore, B-ultrasound should be done around 60 days. At this time, you can see whether the gestational sac, fetal bud and fetal heart are normal.

The period from the third trimester to the first month and four weeks of pregnancy is called the embryonic stage. The embryo is 0.5-1 cm long and shaped like a small seahorse.

3. The size of the embryo

Normally, the embryo can be seen on ultrasound at 6-7 weeks of pregnancy.

4 weeks: The fetus is only 0.2 cm. The amniotic cavity is formed just after the fertilized egg has implanted and its volume is very small. Ultrasound cannot show clear signs of pregnancy.

5 weeks: The fetus grows to 0.4 cm and enters the embryonic period. The amniotic cavity expands and primitive cardiovascular system appears, which may beat. B-ultrasound can show a small gestational sac, which occupies less than 1/4 of the uterine cavity, or a fetal bud can be seen.

6 weeks: The fetus grows to 0.85 cm, and the head, brain alveoli, facial organs, respiratory, digestive, and nervous organs are differentiated. The fetal sac is clearly visible on B-ultrasound, and the fetal bud and fetal heartbeat are seen.

7 weeks: The fetus grows to 1.33 cm. The embryo has the rudiments of a human being. The body segments are fully differentiated, the limbs are separated, and various systems are further developed. B-ultrasound clearly shows the embryo and fetal heartbeat, and the gestational sac occupies about 1/3 of the uterine cavity.

8 weeks: The fetus grows to 1.66 cm. The fetal shape is determined, and the head, body and limbs can be distinguished. The head is larger than the trunk. B-ultrasound shows that the gestational sac occupies about 1/2 of the uterine cavity, the fetal shape and fetal movement are clearly visible, and the yolk sac can be seen.

9 weeks: The fetus grows to 2.15 cm, the head is larger than the body, the various parts are clearer, the skull begins to calcify, and the placenta begins to develop. B-ultrasound shows that the gestational sac almost fills the uterine cavity, the fetal outline is clearer, and the placenta begins to appear.

10 weeks: The fetus grows to 2.83 cm, all fetal organs have been formed, and the rudiments of the placenta are formed. B-ultrasound shows that the gestational sac begins to disappear, a crescent-shaped placenta is visible, and the fetus is active in the amniotic fluid.

11 weeks: The fetus grows to 3.62 cm, the fetal organs develop further, and the placenta develops. B-ultrasound showed that the gestational sac had completely disappeared and the placenta was clearly visible.