In previous years, the indications for cesarean delivery in China were relaxed too much, resulting in more than 50% of women who are ready to have another baby having a history of cesarean delivery. So, can women who are pregnant again after a cesarean be allowed to try for labor? Most of the literature and the most authoritative clinical guidelines are still from the United States, where more information and data have been accumulated on this issue. One indicator that can provide a reference is the lower uterine incision thickness, which refers to the thickness of the muscle layer at the lower uterine cesarean incision site as measured by ultrasound. Some experts believe that this thickness is related to the rupture of the lower uterine segment during a vaginal trial of labor, and that the thinner the lower uterine incision thickness, the greater the risk of uterine rupture during the trial of labor. However, most experts believe that there is no universally acceptable standard value to predict uterine rupture, and that the values obtained vary widely depending on the method of measurement. The recommended reference standard is now 3 mm. The US guidelines for vaginal trial of labor after cesarean delivery suggest that in general, the success rate of vaginal trial of labor after cesarean delivery is 60 to 80%. The rate of uterine rupture during vaginal trial of labor in pregnant women with a history of cesarean delivery is 0.7 to 0.9%. The probability of uterine rupture is related to the length of time between pregnancies. If the time between pregnancies (time between cesarean delivery and second pregnancy) is within 6 months, the probability of uterine rupture is 2.7% when attempting trial of labor after cesarean delivery, and 0.9% when attempting labor beyond 6 months. Regarding how long after a cesarean delivery a trial of labor can be considered for pregnancy, there should be an interval of more than 9 to 15 months between the previous cesarean delivery and the next pregnancy. For women who are not in a hurry to get pregnant again, a longer waiting period is preferable. However, for women who are older and want to get pregnant again sooner, and for women who are already pregnant again, they should be allowed to consider a trial of vaginal delivery if they are pregnant 9 to 15 months after their cesarean delivery. The data on the time between cesarean delivery and second pregnancy and spontaneous uterine rupture are relatively scarce, and data from the ACOG (American College of Obstetricians and Gynecologists) guidelines suggest that the incidence of uterine rupture in pregnant women who are proposed for elective repeat cesarean delivery is 0.4 to 0.5%, with no indication of the time between the last cesarean delivery and second pregnancy. So even if you get pregnant again within a few months after a cesarean delivery, it is not that scary, the probability of spontaneous uterine rupture exists, but it is not as high as it is thought to be. It’s just that the probability of uterine rupture increases threefold, at around 3%, if the pregnant woman wants to deliver vaginally. If you don’t want to give birth on your own, but choose to have another cesarean, the probability of spontaneous uterine rupture is probably no more than 1%. Another question is: Is it possible to try to deliver vaginally after two consecutive cesarean sections? In a large sample, the success rate of vaginal trial of labor for those with a history of two lower uterine cesarean sections was 71% and the rate of uterine rupture was 1.36% compared to one lower uterine cesarean section. Overall the success rate is acceptable and the risks are manageable. Vaginal trial of labor can be considered with adequate information about the risks and informed consent.