How Long Has It Been Since Conception with a 6mm Embryo?
The embryonic bud is the fertilized egg after implantation, which attaches to the uterus and continuously differentiates with the increase of pregnancy time. The size of the embryonic bud is related to the duration of pregnancy. If the embryonic bud is only 6mm, it means that the woman has just been pregnant for a short time, approximately one month. At this time, the embryonic bud has not yet differentiated into a human form, and only a small gestational sac can be seen under B-ultrasound, but the fetal heart and heartbeat can be observed.
At 4 weeks, the fetus is only 0.2 centimeters. The fertilized egg has just completed implantation, and the amniotic cavity has just formed, with a very small volume. Ultrasound cannot yet see signs of pregnancy. At 5 weeks, the fetus grows to 0.4 centimeters, entering the embryonic stage, with the amniotic cavity expanding and the primitive cardiovascular system appearing with pulsations. B-ultrasound can see a small gestational sac, which occupies less than 1/4 of the uterine cavity, or the embryonic bud can be seen. At 6 weeks, the fetus grows to 0.85 centimeters, with differentiation of organs such as the head, brain vesicles, facial organs, respiratory, digestive, and nervous systems. B-ultrasound clearly shows the gestational sac, embryonic bud, and fetal heartbeat. At 7 weeks, the fetus grows to 1.33 centimeters, and the embryo has taken on a human shape with all body segments differentiated, limbs separated, and various systems further developed. B-ultrasound clearly shows the embryonic bud and fetal heartbeat, and the gestational sac occupies about 1/3 of the uterine cavity. At 8 weeks, the fetus grows to 1.66 centimeters, with a definite fetal shape and distinguishable fetal head, body, and limbs, with the fetal head larger than the trunk. B-ultrasound shows that the gestational sac occupies about 1/2 of the uterine cavity, and the fetal morphology and fetal movements are clearly visible, as well as the yolk sac.
After the sperm and egg combine to form a fertilized egg, it implants and slowly divides into a multicellular gestational sac. After more than 30 days of pregnancy, the primitive cells differentiate to gradually form an embryonic bud, which further develops into a fetal heart. This is the process of fetal formation. Usually, the period from three weeks of gestation to the first month of pregnancy is called the embryonic bud stage. At this time, B-ultrasound or color Doppler ultrasonography can detect blood flow signals with cardiac fluctuations, and further growth and development lead to the formation of a fetus.
Pregnancy is a complex process that begins with the implantation of the fertilized egg and continues through the formation of the gestational sac, embryonic bud, fetal heart, and fetus. Each week of pregnancy brings different changes. Using B-ultrasound to assess fetal development and size is a relatively accurate method. Pregnant women can observe the entire process of their fetus from initial growth and development to maturity through numerical values.
