A woman’s 1 week of pregnancy is 7 days, which does not differ from the normal calculation of time. A woman should know her last, menstrual period to estimate the due date by adding 9 or subtracting 3 to the month of her last period and adding 7 to the number of days to calculate the due date. The exact time of delivery can also be estimated by clinical ultrasonography. The entire gestation period during pregnancy is 280 days, i.e. 40 weeks, but it depends on the woman’s specific situation. Pregnancy of 37-42 cycles is considered full-term, but births between 28 and 37 full weeks are called preterm. During pregnancy, women should pay attention to balanced nutrition, eat nutrient-rich food, stay away from harmful substances and radiation, do regular checkups, observe the fetus, and pay attention to rest and warmth in life.