The timing of second trimester pelvic entry does not correlate much with the timing of delivery. The majority of second-trimester pregnancies, i.e., menstruating mothers, come into labor after delivery. Some women go into labor on the day they are due and before labor starts, but some women go into labor after labor starts and as labor progresses, so the time of going into labor is generally not necessarily related to the time of delivery. The time of pelvic induction is difficult to determine and needs to be clarified by prenatal examination. After the fetus is in the pelvis the pregnant woman feels that the fetus is descending, the epigastrium is more comfortable than before, and symptoms such as frequent urination, incomplete urination and abdominal pain occur. The fetus in transmaternal women may have a high floating fetal head that does not enter the pelvis, mostly after it enters the prodromal stage of labor. Therefore, the progress of labor should be judged by the presence or absence of regular contractions after the fetus is in the pelvis. In addition, even if the second fetus is in the pelvis, it may come out of the pelvis again because the belly of a transitional mother is looser, the pelvis is shallower, and the fetus has more room to rotate, so the pregnant woman does not need to dwell on whether the fetus is in the pelvis or not.