17- ectopic pregnancy

Ectopic pregnancy is when a fertilized egg implants outside the uterine lining, typically in a fallopian tube.
The most common site is the fallopian tube (tubal pregnancy).
Ectopic pregnancies account for 1.5-2.0% of all pregnancies.
They are a leading cause of pregnancy-related deaths in the first trimester (4-10%).
Tubal pregnancies are the most common type, accounting for >95% of ectopic pregnancies. Classification by location within the tube includes ampullary (70%), isthmic (12%), fimbrial (11%), and interstitial (2%).
Other types of ectopic pregnancies include cervical, ovarian, cesarean scar, and abdominal pregnancies (less common).
Risk factors include previous pelvic inflammatory disease (PID), previous tubal surgery, endometriosis, uterine fibroids (leiomyomas), abnormal tubal anatomy (e.g., from DES exposure), and use of assisted reproductive technologies (ART).
Approximately one-third of ectopic pregnancies in women without apparent risk.
Smoking dramatically increases the risk of ectopic pregnancy (affects cilia and smooth muscle function in the fallopian tube).
IUD use is associated with about 5% of ectopic pregnancies.
Tubal pregnancies are often the first factor when a pregnancy fails.

Tubal ectopic pregnancies are more common than non-tubal cases.
- Ampullary (70%)
- Isthmic (12%)
- Fimbrial (11%)
- Interstitial (2%)
Other ectopic pregnancies are less common:
- Cervical
- Ovarian
- Cesarean scar
- Abdominal

Heterotopic pregnancy is when a woman has both an intrauterine pregnancy and an ectopic pregnancy.
It's a rare condition less frequent than spontaneous pregnancy.
The incidence increases with assisted reproductive technologies (ART).

Isthmic pregnancies rupture earlier (6–8 weeks) due to the narrow diameter of the fallopian tube at that point.
Ampullary pregnancies rupture later (8–12 weeks).
Interstitial pregnancies rupture latest (12–16 weeks) because fallopian tube is located near the uterus, making it larger.
Interstitial rupture is potentially dangerous due to proximity of uterine and ovarian blood vessels.

Preventing or treating sexually transmitted infections can prevent tubal damage and future ectopic pregnancies.
Quitting smoking can help reduce the risk of ectopic pregnancy.
Removing fallopian tubes prior to IVF in cases of infertility might help reduce ectopic pregnancies in patients receiving IVF.

Ectopic pregnancy has no distinguishing signs or symptoms.
May present similarly to other disorders (normal pregnancy, threatened abortion, ovarian cyst rupture, ovarian torsion, gastroenteritis, or appendicitis).

Pelvic/abdominal pain is a common symptom (100%).
Pain can be unilateral, bilateral, localized, or diffuse.
Subdiaphragmatic or shoulder pain often indicates intra-abdominal bleeding. This is another early symptom of a ruptured ectopic pregnancy.
Hemorrhage from the trophoblast invading blood vessels within the fallopian tube.

Abnormal uterine bleeding (75%) reflects shedding of endometrial tissue.
Decidual cast (passed in 5%-10% of ectopic pregnancies), can be erroneously mistaken as products of conception.
Vaginal bleeding can occur due to insufficient progesterone support, particularly in absence of uterine lining function.

Dizziness, lightheadedness, or syncope are potential symptoms of intra-abdominal bleeding from a ruptured ectopic.
This should raise suspicion.
Vital signs should alert patients to the presence of the potential rupture of the fallopian tube.

Uterine changes (softening and slight enlargement) may occur, though may overlap with other pregnancies.
Hemodynamic instability, manifested by changes in vital signs, frequently indicates intra-abdominal bleeding in patients with tubal rupture.

Hematocrit (indirect assessment of hemodynamic status).
Beta-hCG (qualitative assays are virtually 100% positive in ectopic pregnancies).
Quantitative hCG with ultrasound can diagnose ectopic pregnancies.
Serial hCG monitoring is helpful in questionable cases.

Normal pregnancy hCG levels should increase by a certain percentage.
Elevated hCG levels combined with nondiagnostic ultrasound usually indicate ectopic pregnancies or potentially abnormal pregnancies.
A low serum progesterone (<5 ng/mL) level may indicate an ectopic pregnancy, though progesterone levels are not always reliable to pinpoint exact location.
Progesterone levels >20 ng/mL are associated with normal pregnancies.

Ultrasound is key in diagnosing ectopic pregnancies and can visually confirm the presence of an intrauterine/ectopic pregnancy in patients with pregnancy.
A diagnosis of "pregnancy of unknown location" is made if intrauterine/ectopic pregnancy cannot be confirmed within the fallopian tube.

Diagnosis can be further complicated by determining that an adnexal mass is not a cyst in early pregnancy. This is often difficult and can only be determined through close monitoring.

D&C (dilation and curettage) may not be ideal in early pregnancy when either treatment or prevention is still needed.
Surgery (laparotomy or laparoscopy) is indicated for hemodynamically unstable patients with a presumed ectopic pregnancy.
Ultrasound prior to surgery is standard for precise diagnosis and prevention of unnecessary procedures.
A diagnosis of tubal rupture is the main indication for laparotomy for prompt treatment and prevention of fatal bleeding.

Expectant management (for asymptomatic patients with low initial hCG levels and evidence of resolution).
Medical management (methotrexate, for hemodynamically stable patients).
Surgical management (laparotomy or laparoscopy, for patients with contraindications to medical management or evidence of tubal rupture).

Either linear salpingostomy or salpingectomy is used to treat tubal pregnancies.
hCG levels may remain elevated despite a successful salpingostomy.
A second ectopic pregnancy may arise from an ectopic salpingostomy.
If the unaffected tube is healthy, salpingectomy is preferred to reduce the risk of future ectopic pregnancies

Methotrexate (MTX) therapy is considered to be reasonably effective to treat asymptomatic pregnancies without rupture.
Success rates are over 80%.

Immediate surgery is necessary for ruptured ectopic pregnancies.
Conservative management is not suitable for ruptured ectopic pregnancies.
Rh(D) immunoglobulin may be required for Rh-negative mothers to prevent sensitization.