In this case, the first thing to do is to have an obstetric ultrasound to assess the size of the fetus. If the membranes have ruptured but the fetal head is not yet in the pelvis, the first consideration is that there is cephalopelvic disproportion, a narrow pelvis and a large fetal head. If the ultrasound indicates that the fetal biparietal diameter is greater than 9.5 cm, a vaginal examination will be done to evaluate the pelvis. If the pelvis is indeed narrow, a cesarean section should be performed in time to terminate the pregnancy. If the ultrasound indicates that the fetal head is not large and the vaginal examination shows that the pelvis is spacious, the trial of labor can be continued in this case. If the fetal head does not enter the pelvis, it may be because the cervical cervix is not well matured, you can give medication to promote cervical maturation, and after the cervical cervix is matured, then proceed to trial of labor. If the amniotic fluid ruptures, observe the amount and color of the amniotic fluid and whether there is any odor, observe the fetal heartbeat and fetal movement, and terminate the pregnancy by cesarean section in time if there is any abnormality.