Key content
Incidence of caesarean scar pregnancy (CSP) is increasing because
of a rising number of caesarean sections. Prompt diagnosis of the
condition is required to reduce associated morbidity.
A high index of suspicion is required for women with a suggestive
history of CSP. Ultrasound scan is the diagnostic tool of choice.
Management options include medical, surgical and interventional
radiology. Appropriate patient selection is important for
optimal results.
Major haemorrhage and hysterectomy are the main
risks associated with CSP. Therefore, adequate counselling
and availability of surgical expertise and blood
transfusion should be part of a comprehensive
management strategy.
Learning objectives
Understand the clinical and ultrasound features of CSP and
distinguish these fromfeatures of other lowimplantation pregnancies.
Learn about available treatment options and the factors
influencing treatment choices.
Be aware of the ethical issues associated with the diagnosis of
live CSP.
Ethical issues
Do women planning subsequent pregnancy after a resolved CSP
require surgery to close the uterine defect in the scar to prevent
recurrent scar ectopic pregnancy?
Should the risk of CSP in a future pregnancy be routinely discussed
prior to primary caesarean section?
Keywords: caesarean section / ectopic pregnancy / hysterectomy /
scar ectopic / ultrasound diagnosis
Linked resource: Single best answer questions are available for this
article at: https://stratog.rcog.org.uk/tutorial/tog-online-sba-resource
Introduction
Pathophysiology
Ultrasound criteria for diagnosis of caesarean scar pregnancy
(CSP)
Empty uterine cavity and closed and empty cervical canal
Placenta and/or a gestational sac embedded in the scar of a
previous caesarean section
A triangular/round or oval-shaped gestational sac that fills the
niche of the scar
A thin or absent myometrial layer between the gestational sac
and the bladder
Yolk sac, embryo and cardiac activity may or may not be present
Evidence of functional trophoblastic/placental circulation on
colour flow Doppler examination, characterised by high velocity
and low impedance blood flow
Negative ‘sliding organs’ sign
Management options for caesarean scar pregnancy (CSP)
Expectant
management
Use very rarely in selected cases
Medical management Systemic methotrexate
Local injection and
embolisation
Local injection of methotrexate with
sac aspiration
Local injection of other embryocides
Uterine artery chemoembolisation
Surgical management Dilatation and surgical evacuation
Hysteroscopic resection
Vaginal excision and resuturing
Laparoscopic excision and resuturing
Open excision and resuturing
Combined laparoscopic and
hysteroscopic procedure
Combined laparoscopic and
vaginal surgery
Hysterectomy
Combined or
sequential
management
Uterine artery embolisation/
chemoembolisation followed by
dilatation and evacuation/surgical
resection in 24–48 hours
Methotrexate followed by surgical
evacuation or resection after an interval
Conclusion
Diagnosis and management of CSP needs considerable
expertise and a multidisciplinary approach to prevent
complications. Increasing CS rates imply that clinicians will
encounter CSP from time to time. A primary preventive
strategy is to focus on reducing the number of primary CS
performed without medical indications. The risk of longterm
complications such as CSP and placenta accreta should be specifically emphasised when counselling women
requesting CS for nonmedical reasons. Prompt and
accurate diagnosis of CSP and individualised treatment and
follow up are required to reduce overall morbidity.