Standard value of gestational sac size at 7 weeks

Whether the size of the gestational sac is consistent with the gestational age often reflects whether the child's development is healthy. Especially for those who are in the early stages of pregnancy, they need to be more careful and observe the size and development of the gestational sac at any time. So what is the standard value of the gestational sac size at 7 weeks of pregnancy? Next, I will introduce the gestational sac at different gestational weeks in detail, hoping it can help you.

The gestational sac is only seen in early pregnancy. For women who have regular menstruation of 28 to 30 days, after 35 days of amenorrhea, the gestational sac can be seen in the uterine cavity by B-ultrasound. The size of the gestational sac can reflect the number of weeks, and the specific reference values ​​are as follows:

Gestational sac size and gestational age comparison table

Pregnancy begins with fertilization. After the egg is fertilized, it enters the uterine cavity, and the embryo and its appendages grow and develop rapidly until maturity. During this process, the gestational sac will undergo different changes in each week 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. Ultrasound showed that the gestational sac began to disappear, the crescent-shaped placenta was visible, and the fetus was active in the amniotic fluid.

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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.

12 weeks: The fetus grows to 4.58 cm, the external genitalia begin to develop, any deformities will be revealed, and the calcification of the skull becomes more complete. The skull halo is clear and the biparietal diameter can be measured. Obvious deformities can be diagnosed and the organs will tend to improve in the future.

Although the gestational sac changes differently at different times, it always remains within a relatively constant range. The size of the gestational sac can not only determine the gestational age of the fetus, but is also an important criterion for determining whether the fetus is growing and developing healthily.