Safe Service Delivery of a Complex Early Pregnancy Problem: Caesarean Scar Pregnancy

Abstract

Caesarean Scar Pregnancy (CSP) is an ectopic pregnancy with implantation into the niche of the uterine scar. We aimed to describe the local management of consecutive cases of CSP to develop a standard operating procedure (SOP). Between December 2019 and June 2022, there were 19,100 maternities. Of these, 23 were CSPs in 19 patients. Median BMI was 29 (range 20.5-52), median number of Caesarean deliveries (CS) was 2 (range 1-4) and 7/23 (30%) were cigarette smokers. At diagnosis, 9/23 were live pregnancies, 3/23 were retained products of conception (RPOC), 9/23 were pregnancies of uncertain viability (PUV), and 2/23 were non-viable. In six, the initial management was expectant, surgical suction evacuation with transrectal ultrasound guidance in 16, and one had a hysterectomy. The median blood loss was 100 mL (range 50-2000 mL). Two patients (9%) required a blood transfusion. Median hospital stay was 1 day (range 0-4). At follow-up after 10 weeks, no patients had an ongoing haematoma, and one had significant RPOC electing hysterectomy. Eight women were known to have 9 subsequent pregnancies (recurrent CSP n = 4, livebirth n = 2, miscarriage n = 2, tubal ectopic n = 1). Outcomes as rated by low blood loss, short hospital stay, and rare need for further intervention were favorable. Factors associated included prompt ultrasonographic diagnosis, availability of transrectal ultrasound guided surgery, and specialist follow-up, which form the basis of the SOP.

Keywords: caesarean scar pregnancy; early pregnancy loss; service provision; ultrasound.

Figure 1

Caesarean Scar Pregnancy types as per Delphi consensus: Type 1 where the largest part of the gestational sac (GS) protrudes towards the uterine cavity; Type 2 where the largest part of the GS is within the myometrium but not breaching the serosa, and Type 3 where the pregnancy is partially located outside of the contour of the cervix or uterus.

Figure 2

Flowchart of Caesarean Scar Pregnancy cases and management.

Figure 3

Intraoperative transrectal ultrasound guidance is crucial to ensure complete evacuation of the uterine cavity and caesarean scar niche.

Figure 4

Histopathological hysterectomy specimen where invasive retained products of conception was present following medical termination of pregnancy. Photograph by Dr. Danah Saif.

Figure 5

Longitudinal ultrasound images of five cases (case A–E) managed surgically with cerclage and balloon. The initial image was obtained on day 3 (D3) at the time of cerclage removal, and subsequent images are obtained between day 26 and 103 post surgical management. In 4/5 the haematoma present on day 3 resolves, whereas in one (A), retained products of conception is diagnosed at day 38 post surgery.

Figure 6

(A) Vertically transected hysterectomy specimen with trophoblast in the uterine niche measuring 20 × 15 mm². (B) B-mode sagittal view of the uterus correlating with (A). (C) Hysterectomy specimen with a blue inked appearance illustrating perforation of the left uterine isthmus by trophoblast measuring 56 × 44 mm². Photograph by Dr. Maria Rosario Oliviera Diz.