Occiput-spine relationship: shoulders are more important than head

BACKGROUND:To understand the role of fetal spine position in determining a fetal head position at the time of birth and modality of delivery.PATIENTS AND METHODS:This was a multicenter prospective observational study. Fetal occiput and spine position were evaluated by intrapartum ultrasound. Eighty-six women were eligible for inclusion in the study. Occiput rotational movements and modality of delivery in relation to the fetal spine position were investigated.RESULTS:At the beginning of labor, fetal occiput was in a posterior position in 52.3% of cases and, in 81.5% of cases the spine was in an anterior transverse position. At birth, occiput and spine were both in an anterior position in 90.4% of cases. The rate of cesarean sections in the SP group was significantly higher than the rate in the SAT group (50% vs. 8%, p < 0.0007). Instead, the rate of vaginal deliveries without intervention in the SP group was significantly lower than the rate in the SA group (14% vs. 71%, p < 0.0001).CONCLUSIONS:Fetal spine position could have an important role in determining fetal occiput position at birth. Spine position might play a crucial role in the outcome of delivery.