fetal position, 1. the relationship of the orientation of the presenting part of the fetus to the four quadrants of the maternal pelvis, identified by initial L (left), R (right), A (anterior), and P (posterior). The presenting part is also identified by initial O (occiput), M (mentum), and S (sacrum). If a fetus presents with the occiput directed to the posterior aspect of the mother’s right side, the fetal position is right occiput posterior (ROP). Compare fetal attitude, fetal presentation. 2. the assumption of a posture by a child or adult resembling that of the fetus in the womb. The limbs are drawn in closely to the body, the head is bent forward, and the back is curled.
