Ultrasound evaluation of the uterine cesarean section scar

Niches have shown to be quite prevalent and can be visualized by transvaginal ultrasound. With this thesis we added the first practical guidelines on niche evaluation in non-pregnant women and in early pregnancy to detect a cesarean scar pregnancy. They can be used in daily clinical practice and will hopefully establish uniformity in future niche studies and increase awareness for the existence of a cesarean scar pregnancy amongst all sonographers performing ultrasound in early pregnancy after cesarean section. During evaluation, it should be considered that niche presence and features change over time after cesarean section. Niche presence disturbs uterine peristalsis, possibly causing niche-related symptoms and subfertility, but this must be further assessed. Its presence does not appear to be affected by uterine closure technique, although the learning curve of uterine closure does seem important. Laparoscopic niche resection increases the residual myometrial thickness, which is favorable during subsequent pregnancy; future research will have to focus on the improvement of obstetric outcomes by laparoscopic niche resection. As a cesarean section cannot be prevented in obstetric policy, proper counseling of women with or without medical indication for a cesarean section should be part of daily practice, including niche-related symptoms. This should be done before but otherwise during follow-up after the cesarean section. Furthermore, recognizing these symptoms in primary care will lead to a sense of understanding in women and not cause an unnecessary delay in therapeutic management.