asynclitism
nounMedical Definition of asynclitism
: presentation of the fetal head during childbirth with the axis oriented obliquely to the axial planes of the pelvis
Back pain or prolonged active labor is sometimes caused by a subtle malposition called asynclitism, in which the baby's head is tilted and the top of it isn't centered on the cervix. — Penny Simkin et al., Pregnancy, Childbirth, and the Newborn: The Complete Guide, 4th edition, 2010