Frequently Asked Questions

IMP is an extremely rare and poorly understood type of ectopic pregnancy. Due to its rarity, IMP is difficult to study systematically, and there are currently no evidence-based diagnostic or management guidelines. The risks—including uterine rupture, haemorrhage, and loss of fertility—can be severe, particularly when diagnosis is delayed or misinterpreted. To address this gap, the IMP Registry has been developed to collect anonymised clinical data prospectively from healthcare professionals managing cases of IMP. The goals of the registry are to: Improve understanding of the natural history, risk factors, and clinical presentation of IMP Identify effective diagnostic and treatment strategies Support evidence-based clinical decision-making Inform national and international management guidelines Ultimately improve patient safety, fertility preservation, and health outcomes By capturing real-world data on the diagnosis, progression, and treatment of IMP, the registry seeks to promote research and establish a more robust foundation for managing this high-risk condition.

Healthcare professionals managing patients with confirmed or suspected IMP are eligible to participate.

The steering committee managing the registry will actively encourage healthcare professionals to submit data. Clinicians can request secure access to the web-based data entry system by contacting uclh.epunurses@nhs.net or using the contact page on this site. Once registered, participants will receive training materials and ongoing support to ensure accurate and consistent data entry. The registry collects only anonymised clinical information, which is submitted through a secure online platform. Clinicians contribute by answering a series of standardised questions designed to ensure high-quality, reliable, and comparable data across all cases.

All data entered into the registry is anonymised. No personally identifiable information is collected. Data is stored securely and managed in compliance with data protection regulations.

The data will be used to: Evaluate outcomes and complications associated with IMP Identify patterns in diagnosis and treatment Inform research studies Support clinical guideline development Only confirmed cases of IMP will be kept in the database. All submissions will be reviewed by an expert medical team, and cases that are not IMP will be removed. We will discuss with contributors if we determine that a case is not IMP and explain our assessment. Patient confidentiality will always be protected.

The IMP Registry is managed by a steering committee made up of relevant stakeholders, including researchers specialising in IMP, healthcare professionals experienced in diagnosing and treating IMP, individuals with personal experience of IMP, and patient advocates who support those affected by the condition. This diverse committee ensures ethical governance, maintains data quality, and oversees the appropriate and responsible use of the registry’s data.

Only authorised personnel at participating centres can enter and access data from their own institution. Access to combined or broader datasets is restricted to a limited number of authorised members of the steering committee to ensure data security and confidentiality.

At this time, patients cannot access the registry directly. However, feedback from patients is welcome. If you would like to share your experience or ask questions, please contact the registry team at uclh.epunurses@nhs.net.

Yes. This is the first registry dedicated specifically to intramural pregnancy. It represents a major step toward improving understanding, treatment, and outcomes for this rare condition.

By collecting and analysing real-world data, the registry will aim to help: Identify best practices for diagnosis and treatment Reduce delays in diagnosis Minimise complications Improve outcomes for women affected by this high-risk condition This evidence will support clinicians in making informed decisions and help guide future research and clinical guidelines.

An IMP is a rare and potentially life-threatening type of ectopic pregnancy where the gestational sac implants within the myometrium of the uterine corpus, above the internal cervical os, and distinctly separate from the interstitial portions of the fallopian tubes, with the key morphological feature being implantation beyond the endometrial-myometrial junction. It was first described in 1913, and is now recognised as a distinct type of uterine ectopic pregnancy. Some people also refer to IMP as a myometrial pregnancy, subperitoneal pregnancy, or subserosal pregnancy. References

IMP can pose significant risks to maternal health, particularly if the condition is misdiagnosed, detected late, or if the pregnancy is continued. Potential complications include: Uterine rupture Severe haemorrhage Emergency hysterectomy Placenta accreta spectrum (PAS) disorders These risks highlight the importance of early and accurate diagnosis. While many cases occur in women with a history of uterine trauma—such as prior surgery, dilation and curettage, or assisted reproductive procedures—IMP can also arise in women without any identifiable risk factors. As such, careful imaging and clinical assessment should be conducted in all pregnancies to ensure implantation has not breached the endometrial–myometrial junction. References

There is currently no standardised treatment protocol for IMP. Management is highly individualised and depends on several clinical factors, including the implantation site, gestational age, pregnancy viability, severity of symptoms, clinician expertise, available resources, and the patient’s reproductive goals. Treatment options may include: Expectant management – In carefully selected cases, after counselling when the pregnancy is viable and desired. Medical therapy – Systemic or local administration of methotrexate may be used, and in some cases, direct injection of potassium chloride into the gestational sac. Other interventions – Uterine artery embolisation may be considered to control bleeding or reduce vascular supply to the pregnancy. Surgical management – Depending on clinical need, this can include transcervical suction curettage, hysteroscopic resection, laparoscopic surgery, open surgical excision, or—when necessary—hysterectomy. Given the complexity and rarity of IMP, referral to a specialist or expert centre is strongly recommended to ensure safe, effective, and individualised care. References

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