D and Xs are carried out between 20 and 24 weeks' gestation,  and typically comprise four steps: cervical dilation; breech conversion; breech extraction, excluding the fetal head; and cephalocentesis to induce vaginal delivery of the intact fetus.
 Cephalocentesis reduces the diameter of the fetal skull, permitting safe vaginal delivery, which would otherwise be life-threatening.
amniodrainage, cephalocentesis; a midwife to attend to the patient and keep her comfortable during the procedure; a scrub sister to assist with the procedure, including collecting and labelling blood specimens; and a sonographer/assistant to 'drive' the ultrasound machine as required during the procedure.
Of the 134 brain anomalies, 52 were hydrocephalus; 38 of these women accepted LTOP, and half had concomitant cephalocentesis. There were 27 cases of spina bifida, and in this group 16 women accepted LTOP.
However, this cephalocentesis almost always results in stillbirth or neonatal death within a few days, due to the rapid decompression of the head or needle-induced hemorrhage.
Cephalocentesis is ethically problematic for several reasons.
It is justifiable, then, for the physician to perform cephalocentesis if the woman firmly states an informed, voluntary preference for vaginal delivery.
If this pregnant woman is hesitant about any possibility of cesarean section, one might determine whether her desire to await spontaneous vaginal delivery and cephalocentesis is motivated primarily by (1) the perceived risks of cesarean section to her own health, or (2) her desire not to have to deliver and make caretaking decisions about an affected child.
Given the potential for a relatively good fetal outcome, cephalocentesis, which leads inevitably to fetal or neonatal death, is difficult to defend.