Scar Evaluation after Caesarean by Ultrasound Registry

While the caesarean section (CS) rate is increasing in most Western countries, the long-term effects of this procedure are poorly studied. In this observational prospective cohort study we will evaluate abnormal uterine bleeding and uterine rupture after CS.
Ultrasonography shows a ‘niche’ at the site of the uterine caesarean scar in the majority of women with a CS in the past history. A niche is a triangular, anechoic area at the presumed site of incision. Our primary objective is to develop an anatomical classification of niches and evaluate if this classification can be related to the degree of abnormal uterine bleeding. Our secondary objective is to demonstrate that the presence of a niche and thickness of the lower uterus segment (LUS) during subsequent pregnancy, can predict dehiscence or rupture of the uterus in women with previous caesarean delivery.
The study population consists of women who have had a caesarean delivery 6 to 12 months ago. Gel instillation sonohysterography (GIS) is performed to detect a niche and women are asked to fill in a questionnaire and keep a diary card to discover abnormal uterine bleeding. The questionnaire will be repeated every year for the duration of 5 years.
In case of subsequent pregnancy, transvaginal ultrasound will be performed between 16 and 20 weeks’ and between 36 and 38 weeks’ gestation to detect the presence of a niche and measure the thinnest zone of the LUS. The course of the pregnancy and delivery are recorded. Special attention is paid to any sign of uterine dehiscence or rupture.

The primary hypothesis is that an association exists between the presence of a niche and abnormal uterine bleeding in women who had a previous caesarean section.

Gel instillation sonohysterography is performed 6 to 12 months after caesarean section to detect a niche. Women are asked to fill in a questionnaire and keep a diary card to discover abnormal uterine bleeding.
In case of subsequent pregnancy, transvaginal ultrasound is performed to detect the presence of a niche and measure the thinnest zone of the lower uterus segment.