People often use \”ten months of pregnancy, premature birth\” and \”the time is right\” to describe childbirth after the pregnancy is over. Therefore, some women are unwilling to induce labor at that time and must wait for natural delivery. Among women who give birth naturally, only about 5% give birth on the expected date of delivery, and about 85% give birth within two weeks before and after the expected date of delivery, which is within the normal range. There are about 10