The match between the ultrasound gestational week and the actual gestational week indicates that the time of ovulation and fertilization calculated by means of the last menstrual period as well as the ultrasound is the same, and that there is usually no early ovulation.
1. Actual gestational week: For women with regular menstruation, the actual gestational week is usually counted from the first day after the last menstruation. For women with irregular periods, the actual week of pregnancy is generally calculated from the first day after the last menstrual period. For women with irregular periods, the week of pregnancy is roughly estimated based on the timing of fetal movements and early pregnancy reactions.
2. Ultrasound pregnancy week: is based on the size of the embryo to calculate the weeks, such as according to the embryo’s biparietal diameter, head and hip index, as well as the head circumference, abdominal circumference and other values to calculate the weeks of pregnancy, usually speaking in early pregnancy is more accurate, can be used to correct the gestational age and expected date of birth.
Early pregnancy ultrasound gestational week and the actual gestational week match, indicating that ovulation occurs normally, occurs about 14 days after the last menstrual period, and does not advance ovulation.
It is recommended that pregnant women estimate the gestational week and ovulation period under the guidance of a doctor to determine whether the growth of the fetus is normal.