Clinical Importance of Appearance of Cesarean Hysterotomy Scar at Transvaginal Ultrasonography in Nonpregnant Women Reply

OBJECTIVE: To estimate the association between the appearance of cesarean hysterotomy scars at transvaginal ultrasound examination of nonpregnant women and the outcome of subsequent pregnancies and deliveries. METHODS: A total of 162 women who had ever given birth by cesarean underwent transvaginal ultrasound examination of the hysterotomy scar 6 to 9 months after the latest cesarean delivery. Published ultrasound definitions of large scar defects were used. The appearance of the hysterotomy scar at ultrasound examination was compared with the outcome of subsequent pregnancies and deliveries. Clinical information on subsequent pregnancies was obtained from medical records. RESULTS: Six women were lost to follow-up, leaving 156 for analysis. Of these 156 women, 69 became pregnant after the ultrasound examination (99 pregnancies, 65 deliveries). There were no placental complications or scar pregnancies. At the first repeat cesarean delivery after the ultrasound examination, 5.3% (1/19) of the women with an intact scar or a small scar defect had uterine dehiscence or rupture compared with 42.9% (3/7) of those with a large defect (P=.047), odds ratio 11.8 (95% confidence interval 0.7-746). CONCLUSION: Our results point toward a likely association between large defects in the hysterotomy scar after cesarean delivery detected by transvaginal ultrasonography in nonpregnant women and uterine rupture or dehiscence in subsequent pregnancy. (Obstet Gynecol 2011;117:525-32) DOI:10.1097/AOG.0b013e318209abf

Assessment of Cesarean hysterotomy scar before pregnancy and at 11-14 weeks of gestation: a prospective cohort study

Objective: To compare the appearance and measurement of Cesarean hysterotomy scar before pregnancy and at 11–14 weeks in a subsequent pregnancy. Methods: This was a prospective cohort study of women aged 18–35 years who had one previous Cesarean delivery (CD) at ≥ 37 weeks. Women were examined with saline contrast sonohysterography 6–9 months after CD. A scar defect was defined as large if scar thickness was ≤ 2.5 mm. Women were followed up and those who became pregnant were examined by transvaginal ultrasound at 11–14 weeks. Scar thickness was measured and scars were classified subjectively as a scar with or without a large defect. A receiver–operating characteristics curve was constructed to determine the best cut-off value for scar thickness to define a large scar defect at the 11–14-week scan. Results: A total of 111 women with a previous CD were scanned in the non-pregnant state and at 11–14 weeks in a subsequent pregnancy. The best cut-off value for scar thickness to define a large scar defect at 11–14 weeks was 2.85 mm, which had 90% sensitivity (18/20), 97% specificity (88/91) and 95% accuracy (106/111). In the non-pregnant state, large scar defects were found in 18 (16%) women and all were confirmed at the 11–14-week scan. In addition, a large defect was found in three women at 11–14 weeks that was not identified in the non-pregnant state. Conclusion: The appearance of the Cesarean hysterotomy scar was similar in the non-pregnant state and at 11–14 weeks in a subsequent pregnancy