Oxytocic injection in late pregnancy usually delivers the baby in about 1~3 days, and the exact time cannot be generalized due to the large individual differences of patients. The main role of oxytocin is to promote the contraction of uterine smooth muscle through the drug, so as to promote the progress of the birth, due to the sensitivity of pregnant women to oxytocin is different, so the effective time will be different, if the more sensitive pregnant women, it may be a few minutes after the contraction, the mouth of the uterus can be fully open in about 10 hours, usually two hours after the delivery. If the pregnant woman is not sensitive to the drugs in the oxytocic injection, there may not be contractions, so it is not certain how long it will take to go into labor after the oxytocic injection. It is recommended that pregnant women in the late stages of pregnancy can properly carry out pregnancy yoga, walking and other exercises, and maintain a good mood, can to a certain extent help the delivery. If you feel unwell, you should go to the hospital in time and consult your doctor.