Baby’s head position
Before labor, the baby’s head nestles into the brim of the pelvis easier if the chin is tucked. Midwife Anne Frye explains head position: “The skull is, by far, the most important part of the fetal anatomy…the size and position of the head is the most critical factor regarding the relative ease or difficulty the baby will encounter as he moves through the birth canal.” The ideal fetal flexion/attitude for birth is ‘complete flexion’ which is where the angle of the head is less than 90 degrees and the baby’s chin is tucked to its chest so that the back of the head presents first.
A baby with a firmly tucked chin and crown of the head aimed into the pelvis will have the smallest head circumference and greatest ease while navigating the pelvic cavity. The head will be able to mold more effectively in the birth canal. A baby descending brow-first with their chin extended upward off the chest will present with the widest skull diameter. If the pelvis is too small or the pelvic muscles are too tight, the baby’s head may start to extend upwards off the chest.
Regular chiropractic care, plenty of pelvic tilts, walking, and circular hip movements can help the chin stay flexed. Balancing the lower uterine segment by lengthening the ligaments that secure it in place will also enable the baby to enter the birth canal at the right angle.
[1] Frye, Anne. Holistic Midwifery: A Comprehensive Textbook For Midwives In Homebirth Practice. Vol II. Portland: Labrys Press, 2006. P7
[1] Duff P. “Diagnosis And Management Of Face Presentation.” Obstet Gynecol 1981; 57:105.
