It is not 100% likely that you will go into labor if you have the birth control balloon put in. There are many factors affecting labor, such as the size of the fetus and contractions. The balloon, or cervical dilatation balloon, is one of the most commonly used methods of inducing labor in obstetrics. It is usually used in pregnant women with an immature cervix, which can be mechanically dilated to make the cervix ripe, and then oxytocin can be given to strengthen the contractions; in some cases, the placement of the cervical balloon will induce contractions, which will lead to labor. Fetal weight is calculated before birth based on the ultrasound and the uterine height and abdominal circumference of the pregnant woman, which is not entirely accurate and has a certain degree of error. If the actual weight of the fetus is larger than the assessed weight, or if the weight of the fetus is normal and the pelvis of the pregnant woman is within the normal range but relatively small, relative cephalopelvic asymmetry may occur in the course of labor, and this may also lead to failure of induced abortion. Uterine contractions are a major factor affecting labor. If during labor, tonic uterine contractions are not relieved by treatment or even pathologic contractions occur, vaginal delivery is generally not possible. Not all pregnant women can be induced by water balloon, and the doctor should examine the patient before choosing the most suitable way to induce labor.