Significance of engagement of the fetal head in puerto rican primiparas

I N c L I N I c A L obstetrics it is generally taught that “lightening,” associated with engagement of the fetal head in the true pelvis, occurs in primiparas at 38 weeks of gestation. According to Greenhill’s text: engagement occurs in 70 to 80 per cent of cases within 2 weeks of term, and Eastman2 states that engagement occurs in over 90 per cent of primiparas by the time labor begins. Bader’s study” showed that in 6.3 per cent of primiparas the fetal head was unengaged at the onset of labor, and similar figures have been reported by Farkas” (8 per cent) and by Auer and Simmons5 (8.7 per cent) . The stimulus for the present study came from the recent report of Burke and associates” from the Beth Israel Hospital of Boston. This group investigated the significance of the unengaged vertex in the nullipara at 38 weeks and at term. They found that 75 per cent of these patients show engagement of the fetal head at 38 weeks, and this figure rises to 95 per cent at term. They further noted that those patients in whom the fetal head is engaged at term have a 99 per cent expectation of vaginal delivery, while those without engagement at the onset of labor require cesarean section in 36.4 per cent of cases. During the last ten years at Bellevue Hospital, our obstetrical experience has been in contrast to the above figures. During this