The radiographic preauricular groove: its non-relationship to past parity.

Deep preauricular sulci were identified on abdominal radiographs in 29 of 190 (15%) adult females and in none of 110 adult males. To assess the value of the deep preauricular sulcus as an index of past pregnancy, we examined gravidity and parity records of 190 women, using standard films that included the sacroiliac region. Deep, radiographic preauricular grooves were identified in 4 of 41 (10%) nulliparous women and in 25 of 149 (17%) women with positive pregnancy histories. We also examined radiographs obtained before and after pregnancy in six primigravidas. No evidence of radiographic changes in the preauricular grooves was seen in any of the six women. We conclude that the presence of a deep, radiographic preauricular sulcus is not necessarily an indication of past pregnancy.