The methods of calculating the expected date of labor include the last menstrual period method, the basal body temperature measurement method and the ultrasound examination method.
1. Last menstrual projection method: its projection is based on the complete pregnancy week is 280 days (40 weeks). The specific method is to add 9 (or subtract 3) to the month of the first day of the last menstrual period and add 7 to the date, which can be calculated.
2. Basal body temperature measurement method of projection: generally regard the day of ovulation as the day of fertilization, the curve of the basal body temperature, the day of ovulation is the last day of the hypothermia period. On this basis, add 266 days, that is, 38 weeks, that is, the expected date of labor.
3. Ultrasound projection method: It is suitable for those who have irregular menstruation or whose last menstruation is unknown, etc. The expected date of delivery is estimated by observing the size of the embryo or fetus through ultrasound.