Rare; <1% of all ectopic pregnancies

Ultrasound criteria

1. Empty uterus
2. Barrel-shaped cervix
3. Gestational sac present below the level of the internal cervical os
4. Absence of sliding sign
5. Blood flow around gestational sac using colour Doppler

Sliding sign: Distinguishes cervical ectopics from miscarriages within the cervical canal. When pressure is applied to the cervix using a probe, in a miscarriage, the gestational sac slides against the endocervical canal, but it does not in an implanted cervical pregnancy.

Single serum BHCG should be carried out at diagnosis
BHCG >10,000 is associated with decreased chance of successful methotrexate treatment

Definition: Implantation into the myometrial defect at the site of the previous uterine incision
Prevalence: 1/2000 pregnancies (13% misdiagnosed at presentation)

First-line: Transvaginal/transabdominal ultrasound
Second-line: MRI if diagnosis equivocal

Ultrasound criteria

1. Empty uterus
2. Gestational sac or solid mass of trophoblast located anteriorly at the level of the internal os, embedded at the site of the previous scar
3. Thin or absent layer of myometrium between gestational sac and bladder
4. Prominent trophoblastic/placental circulation on Doppler
5. Empty endocervical canal

Ultrasound criteria

1. Empty uterus
2. POC/gestational sac located laterally in the interstitial/intramural part of the tube and surrounded by <5mm of myometrium in all imaging planes
3. Interstitial line sign: Thin echogenic line extending from the central uterine cavity echo to the periphery of the interstitial sac (sensitivity 80%, specificity 98%)

Definition: Implantation in the interstitial part of the fallopian tube (interstitial part is 1-2cm in length)
Incidence: 1.0-6.3% of ectopic pregnancies

Serum BHCG carried out at diagnosis may aid with management, and may be repeated after 48 hours

Ultrasound criteria

1. Visualisation of a single interstitial portion of fallopian tube in the main uterine body
2. Gestational sac/POC seen mobile and separate from the uterus and completely surrounded by myometrium
3. A vascular pedicle adjoining the gestational sac to the unicornuate uterus

Definition: Implantation in one horn of a bicornuate uterus, or in one lateral half of a uterus of bifid tendency
Incidence: Very rare; 1/76,000 pregnancies

Serum BHCG carried out at diagnosis may aid with management, and may be repeated after 48 hours

No specific agreed criteria for ultrasound diagnosis

Suggestive findings

1. Empty uterus
2. Wide echogenic ring with internal anechoic area on ovary
3. Yolk sac/embryo may be seen
4. Negative sliding organ sign: Not possible to separate cystic structure or gestational sac from ovary
5. Separate corpus luteum
6. Complex echogenic adenxal mass

Serum BHCG carried out at diagnosis may aid with management, and may be repeated after 48 hours

Ultrasound criteria

1. Absence of an intrauterine gestational sac
2. Absence of both an evident dilated tube and a complex adnexal mass
3. Gestational cavity surrounded by loops of bowel and separated from them by peritoneum
4. Wide mobility similar to fluctuation of the sac, evidence with pressure of the probe towards the posterior cul-de-sac

Elevated serum BHCG in combination with ultrasound findings

Definition: IUP and co-existing ectopic pregnancy

Consider in the following:

1. Following ART
2. IUP with persistent pelvic pain
3. Persistently raised BHCG following miscarriage or TOP

Suitability

1. Haemodynamic stability
2. Willingness to attend for follow-up
3. No known sensitivity to methotrexate
4. NICE: No significant pain, serum HCG 1500-5000, unruptured ectopic <35mm, no IUP, no fetal cardiac activity

Repeat serum HCG 48 hours apart: Check that HCG not rising at a rate consistent with viable IUP
DO NOT GIVE AT FIRST VISIT; EXCLUDE VIABLE IUP

Measure BHCG levels on D4 and D7 post-methotrexate: If BHCG decreases by >15% between D4 and D7, then measure weekly until <15, if not then repeat transvaginal ultrasound +/- treatment

Common SE: Flatulence, bloating, elevated liver enzymes, stomatitis
Others: Marrow suppression, pulmonary fibrosis, liver cirrhosis, renal failure, gastric ulceration

Management

1. Medical management with methotrexate (91% efficacy)
2. Surgical management is associated with a high failure rate and should be reserved for those with life-threatening bleeding
3. Conservative: Absence of fetal cardiac activity, <12 weeks, low serum BHCG levels associated with greater success

Management

1. Surgical > medical interventions +/- haemostatic measures
2. Medical (methotrexate either by local injection into gestational sac or systemic IM injection): Trophoblast remains in situ, risk of haemorrhage as retained placental tissue degenerates.
3. Surgical: Either suction evacuation, hysteroscopic resection, excision as open/laparoscopic/transvaginal procedure. Can be combined with cervical cerclage, Foley catheter insertion, or UAE as addtiional haemostatic measures.
4. Expectant: Suitable for small, non-viable ectopics and may be considered if the pregnancy is partially implanted into the scar and grows into the uterine cavity.

Management

1. Conservative: Expectant or pharmacological approach using local or systemic methotrexate. Likely success of conservative measurement determined by initial BHCG level. Expectant is only suitable for women with low or significantly falling BHCG levels in whom addition of methotrexate may not improve outcome.
2. Surgical: Surgical management by laparoscopic cornual resection or salpingotomy is an effective option. Alternative techniques include hysteroscopic resection under laparoscopic or ultrasound guidance.

Likely success of conservative measurement determined by initial BHCG level

Management

1. Excision of the rudimentary horn via laparoscopy or laparotomy

Management

1. Definitive surgical treatment preferred if laparoscopy is required to make a diagnosis. Removal of pregnancy tissue by enucleation or wedge resection is preferred. Oophorectomy may be required if there is co-existing pathology or bleeding.

Management

1. Surgical: Laparoscopy is safe and effective when diagnosis is made early and site of implantation does not involve a vascular area. Advanced abdominal pregnancy should be managed by laparotomy.
2. Medical: Systemic methotrexate with ultrasound guided fetocide.

Management

1. Methotrexate: If IUP is non-viable or TOP.
2. Local injection of potassium chloride or hyperosmolar glucose with aspiration of sac contents (clinically stable). Ultrasound follow-up necessary to ensrue resolution as BHCG cannot be used. This minimises risk to the IUP.
3. Surgical: Preferred method if unstable or with easily accessible ectopic (tubal, cervical, interstitial).
4. Expectant: If pregnancy is non-viable

Women without a history of subfertility of tubal pathology: No difference in rate of fertility, future tubal ectopic, or tubal patency rates between management methods.

Women with a previous history of subfertility: Treatment of tubal ectopic with expectant/medical management is associated with improved outcomes compared to radical surgery

Methotrexate has no effect on ovarian reserve.
Advise women to wait 3 months after treatment before trying to conceive due to length of time present in some organs and concern for fetal development.