Ectopic Pregnancy

Question 1

Definition of ectopic pregnancy

Answer 1

Any pregnancy implanted outside of the endometrial cavity.

Question 2

Incidence of ectopic pregnancy

Answer 2

Approximately 11/1000 pregnancies, with an estimated 11000 ectopic pregnancies diagnosed each year (2-3% of women attending early pregnancy units.)

Question 3

Possible sites of ectopic pregnancy

Answer 3

• The most common site for an ectopic pregnancy is the fallopian tube (97%) (‘tubal’)
• Ampulla is most common, isthmus, fimbria, interstitial, cornua
• Ovary (1-3%)- NOTE the ovary is a solid organ so has the capacity to expand unlike the fallopian tubes
• Cervix (<1%)- mostly posterior
• Abdominal cavity
• C-section scars (hysterotomy scar pregnancies <1%)
• Heterotopic pregnancy= simultaneous development of two pregnancies, one within and one outside the uterine cavity

Question 4

Risk factors for ectopic pregnancy

Answer 4

Tubal damage following surgery or infection, smoking, IVF, previous PID and IUDs, maternal age over 35 years having multiple sexual partners, pregnancy despite contraceptives

Question 5

Complications of ectopic pregnancy

Answer 5

Tubal rupture (occurs in 50% of undiagnosed or untreated cases), maternal death, recurrent ectopic pregnancy, psychological effects (grief, anxiety and depression)

Question 6

PAthophysiology of ectopic pregnancy

Answer 6

• Effective transport of embryos in the fallopian tube requires a delicately regulated interaction between the tubal epithelium, fluid and contents
• Mechanical force is generated by tubal peristalsis, ciliary motion and tubal fluid flow-> drives the embryo towards the uterine cavity (BUT process is susceptible to dysfunction)
• In order for an ectopic to take place:
• Egg must be fertilised and come to rest somewhere other than endometrium
• When it arrives, must implant on a surface with a rich enough blood supply to support a developing embryo
• Following this: The tissue may no longer be able to provide sufficient blood supply for embryo, leading to embryo death (if not, corpus luteum generates signs of early pregnancy)
• If ectopic occurs in the ampulla, it eventually runs out of space and slowly stretches nerve fibres of walls of fallopian tube leading to lower abdominal pain
• Eventually, expansion can damage the ampulla wall and rupture of the fallopian tube. This can lead to massive haemorrhaging into abdominal cavity which irritates peritoneum and gives referred pain to shoulder
• If the ectopic is in the fallopian tubes, pressure increases around weeks 6-8,but pain and bleeding can occur several weeks later if it is elsewhere

Question 7

Presentation of ectopic pregnancy

Answer 7

• Typically presents around 6-8 weeks gestation
• Always ask about the possibility of pregnancy, missed periods and recent unprotected sex in women presenting with lower abdominal pain
• Missed period
• Constant lower abdominal pain in the right or left iliac fossa
• Vaginal bleeding
• Lower abdominal or pelvic tenderness
• Cervical motion tenderness (pain when moving the cervix during a bimanual examination)
• Dizziness or syncope (haemodynamically unstable indicating rupture) and shoulder tip pain (peritonitis indicating rupture)

Question 8

When should hospital transfer be intiated with suspected ectopic

Answer 8

Arrange immediate ambulance transfer to hospital if:
* The woman has signs of haemodynamic instability (Resuscitate with IV fluids)
* There is significant concern about the degree of bleeding or pain

Question 9

What investigations can be arranged in primary care for suspected ectopic

Answer 9

If immediate hospital transfer is not indicated, arrange a urine pregnancy test (if not already done). If pregnancy is confirmed, assess for signs of an ectopic pregnancy.
* Perform a gentle abdominal examination: If there is abdominal pain and tenderness, strongly suspect ectopic pregnancy.
* Arrange immediate admission to an early pregnancy assessment unit (EPAU) or out-of-hours gynaecology service for diagnosis and treatment .
* If there is no abdominal pain and tenderness, perform a gentle pelvic examination.
* Do not palpate for an adnexal or pelvic mass as this may increase the risk of rupture of an ectopic pregnancy if present.
* If there is any pelvic tenderness or cervical motion tenderness, strongly suspect ectopic pregnancy- refer to EPAU

Question 10

Investigations for ectopic pregnancy in secondary care

Answer 10

• TVUSS is the diagnostic tool of choice for a suspected ectopic pregnancy (used to identify the location of the pregnancy and whether there is a foetal pole and heartbeat)
• Foetal heartbeat= viable intrauterine pregnancy (should become visible once foetal pole >7mm)
• If no heartbeat- measure foetal pole (if <7mm re-scan in 7 days)
• If no pole- measure gestational sac (if >25mm likely miscarriage, if below rescan in 7 days)
• Transabdominal may be used in some cases (e.g enlarged uterus or pelvic pathology such as fibroids) but is less sensitive
• MRI may be used 2nd line if there is uncertainty

Question 11

How can a tubal ectopic pregnancy be identified

Answer 11

By visualising an adnexal mass that moves separate to the ovary (corpus luteum will move with the ovary)
* A gestational sac containing a yolk sac or fetal pole may be seen in a fallopian tube.
* Sometimes a non-specific mass may be seen in the tube. When a mass containing an empty gestational sac is seen, this may be referred to as the “blob sign”, “bagel sign” or “tubal ring sign” (all referring to the same appearance)

Question 12

USS criteria for diagnosing a cervical ectopic pregnancy

Answer 12

An empty uterus, a barrel-shaped cervix, a gestational sac present below the level of the internal cervical os, the absence of the ‘sliding sign’ and bloodflow around the gestational sac using colour Doppler

Question 13

What is a pseudogestational sac

Answer 13

Fluid in the uterus

Question 14

Definition of and investigations for a pregnancy of unknown origin

Answer 14

A positive pregnancy test but no visible evidence of the location of the pregnancy on an ultrasound scan
* Measurements of serum human chorionic gonadotrophin (hCG) may be used to determine subsequent management. However, clinical symptoms are of more significance than hCG levels
* The serum HBG should be repeated after 48 hours to measure the change from baseline (in normal pregnancy will double every 48 hours- this will not be the case in miscarriage or ectopic pregnancy)
* A rise of more than 63% after 48 hours is likely to indicate intrauterine pregnancy. THEREFORE, a repeat ultrasound scan is required after 1-2 weeks to confirm an intrauterine pregnancy (should be visible on ultrasound once the hCG level is above 1500 IU/l)
* A rise of less than 63% after 48 hours may indicate an ectopic pregnancy- requires close monitoring and review
* A fall of more than 50% is likely to indicate a miscarriage. A urine pregnancy test should be conducted 2 weeks after this happens to confirm completed miscarriage
* Monitoring women clinically is more important than hCG levels
* Serum progesterone may also be used to evaluate pregnancy viability

Question 15

Management of a PUL

Answer 15

Question 16

Expectant management of ectopic pregnancy + when is it appropriate

Answer 16

Suitable for patients who are haemodynamically stable and asymptomatic
Can be considered where:
* Tubal ectopic pregnancy measures less than 35mm with no visible heartbeat on TVUSS (and unruptured)
* HCG levels are < 1500 IU/L
* Follow up is possible to ensure successful termination

Should repeat hCG levels on days 2, 4 and 7 after the original test
* If hCG levels drop by 15% or more from previous days then repeat weekly until a negative result (less than 20 IU/L) is obtained
* If hCG levels do not fall by 15%, stay the same or rise from the previous value, review the woman’s clinical condition

There seems to be no difference between expectant and medical management in risk of tubal rupture, rate of ectopics ending naturally, need for additional treatment and health status (risk of needing follow up however)

Question 17

Medical management of ectopic pregnancy + when is it appropriate + common side effects

Answer 17

Offer systemic methotrexate to women who:
* Have no significant pain and are haemodynamically stable (who are able to return for follow-up)
* Have an unruptured tubal ectopic pregnancy with an adnexal mass smaller than 35 mm with no visible heartbeat
* Have serum hCG levels less than 5000 IU/L (between 1500-5000 may consider surgery- decreases chances of follow-up tx.)
* DO NOT have an intrauterine pregnancy (confirmed on TVUSS)

Methotrexate should only be offered on first visit when there is definitive diagnosis of an ectopic pregnancy and a viable intrauterine pregnancy has been excluded.
* Methotrexate is teratogenic- given IM into a buttock. This halts the progress of the pregnancy and results in spontaneous termination.
* Women should be advised not to get pregnant for 3 months following treatment (due to harmful long-term effects)

Common side effects: vaginal bleeding, nausea and vomiting, abdominal pain, stomatitis (inflammation of the mouth)

For women with ectopic pregnancy who have had methotrexate, take 2 serum hCG measurements in the first week (days 4 and 7) after treatment and then 1 serum hCG measurement per week until a negative result is obtained

Question 18

Surgical management of ectopic pregnanyc + when is it appropriate

Answer 18

Should be offered 1st line in women presenting with:
* An ectopic pregnancy and significant pain, adnexal mass (>35 mm), foetal heartbeat visible on USS, haemodynamically unstable, serum hCG >5000 IU/L
* Surgery should be performed laparoscopically where possible
* Should have salpingectomy unless they have other risk factors for infertility and have not completed their family
* o Consider salpingotomy as an alternative to salpingectomy for women with risk factors for infertility such as contralateral tube damage
* 1 in 5 will require further treatment (methotrexate or further salpingotomy)
* Require 1 serum hCG measurement 7 days after surgery
* Require a urine pregnancy test after 3 weeks

Question 19

Important considerations for management of ectopic prgnancy

Answer 19

• Medical management with methotrexate should be considered for cervical ectopic pregnancy- surgical methods are associated with a high failure rate and should be reserved for life threatening bleeding
• Caesarean scar pregnancies are associated with severe maternal morbidity and high mortality rate (should be managed surgically)
• Management is similar for interstitial pregnancies, but expectant management is only suitable for very low or falling serum hCG levels. For cornual pregnancy, women require excision of the rudimentary horn via laparoscopy/laparotomy
• Laparoscopic removal of early abdominal pregnancy is possible, laparotomy is preferred in advanced abdominal pregnancy. Can consider systemic methotrexate with USS guided fetocide
• In heterotopic pregnancy also need to consider the intrauterine pregnancy (methotrexate can ONLY be used if this is unviable) Local injection of potassium chloride can be considered (surgery is also an option)
• Offer anti-D immunoglobulin prophylaxis at a dose of 250 IU (50 micrograms) to all rhesus-negative women who have a surgical procedure to manage an ectopic pregnancy or a miscarriage.