[Birth after peri-acetabular osteotomy]

We evaluated the radiological pelvic diameter after the bernese periacetabular osteotomy (PAO) and its influence on the modality of birth. Out of 93 woman, 17 had a total of 28 babies after PAO; 18 children were delivered spontaneously and 10 by caesarean section. The rate of section (36 %) was twice as high after PAO as in a normal population. In 50 % the indication to perform a section was made because the obstetrician anticipated problems during delivering after PAO. The average weight of birth was 3348 g +/- 285 g in the spontaneous delivery group, 3475 g +/- 356 g in the section group. The weight of birth didn't correlate neither with the duration of delivery nor with the indication to perform a section. The 17 woman who had a baby after PAO didn't show a significant change of the radiological diameters of the pelvis: pelvic entrance (before PAO 15. 4 cm, after PAO 15.7 cm), mid-pelvis (before PAO 11.8 cm, after PAO 11.8 cm) and pelvic outlet (before PAO 14.2 cm, after PAO 13.7 cm). We found that the PAO does not influence the anatomical diameters of the birth canal and therefore is not an indication for a section.