Information on Cesarean Scar Pregnancy

In a CSP the gestational sac and the placenta implant on or within a previous cesarean section scar. The incidence of CSP was estimated to range from 1:1,800 to 1: 2,216 pregnancies9. The main risk factor for CSP is a previous cesarean section. Continuation of the pregnancy is associated with an abnormally invasive placenta.. Women can show signs of profound bleeding and in severe cases rupture of the uterus in the area of the scar. In CSP the invasion of the pregnancy into the myometrium occurs through a defect in the uterine scar on the basis of incomplete healing.


Criteria for diagnosing a CSP in a woman with history of cesarean section10


Positive pregnancy test
Visualization of an empty uterine cavity as well as an empty endocervical canal on transvaginal ultrasound
Detection of the placenta and/or a gestational sac embedded in the hysterotomy scar
In the gestational sac an embryonic/fetal pole and/or yolk sac (+/- heart activity) can be seen on transvaginal ultrasound.
A thin (1-3 mm) or absent myometrial layer between the gestational sac and the bladder can be seen on transvaginal ultrasound.
Before 8 weeks’ gestation, a triangular gestational sac fills the niche of the scar. After 8 weeks’ gestation this shape becomes more rounded and part or the entire chorionic sac can be seen approaching into the uterine cavity. However, the placenta and its blood flow remain within or on the scar and define the diagnosis of CSP. In the area of the cesarean scar a prominent and at times rich vascular pattern in color Doppler can be visualized.

The management of women with CSP is challenging. One of the reasons is that CSP can be misdiagnosed as a low-lying intrauterine pregnancy or a cervical pregnancy. Another reason is that there is no widely accepted treatment modality. Termination of a CSP remains challenging as some treatment modalities fail to terminate the pregnancy or cause excessive bleeding requiring laparotomy and hysterectomy.

CSP Registry

We collect data on diagnosis, disease behavior, and management of cesarean scar pregnancies.

Fetal Medicine Unit Lanesborough Wing, 4th Floor,
St. George's Hospital Blackshaw Road, London SW17 0QT United Kingdom