An ectopic pregnancy is a gestation that implants outside of the endomitrial cavity. It represents a serious hazard to a woman’s health and reproductive potential, requiring prompt recognition and early aggressive intervention.
More than 95% of ectopic pregnancies implant in various anatomic segments of the fallopian tube, including the interstitial (1%), isthmic (5%), ampullary (85%), and infundibular portions (9%). Other less common sites of ectopic implantation are the uterine cervix, ovary, and the peritoneal cavity (Fig. 1).
Fig. 1. Possible locations of ectopic pregnancy
Since the early 1970s, the incidence of ectopic pregnancy has tripled, and currently this condition represents the fourth leading cause of maternal mortality overall (4%) and the most common cause of maternal mortality in the first trimester. Several factors have been implicated as contributing to this increased incidence:
Improved technology, which has allowed for earlier and more complete diagnosis of some patients whose condition went undetected in the past.
The rising incidence of acute and chronic salpingitis, induced abortion, tubal ligation, tubal reconstructive surgery, and conservative management of tubal pregnancy, all of which result in histologic and structural damage to the tubes.
The use of intrauterine contraceptive devices (IUDs). Women with IUDs are four times more likely to suffer from an ectopic pregnancy. This effect is due to the better protection afforded by IUDs against intrauterine compared with extrauterine pregnancy and the higher incidence of pelvic inflammatory disease among IUD users.
The overall incidence of ectopic pregnancy is estimated to be at least one in every 200 pregnancies.
Probably as many as 50% of cases result from alteration of tubal transport mechanisms secondary to damage to the ciliated surface of the endosalpinx caused by infections such as Chlamydia and gonorrhea. Others are the result of intrinsic abnormalities of the fertilized ovum and possibly transmigration of the oocyte to the contralateral tube, with resulting delays in passage.
Tubal pregnancies rapidly invade the mucosa, feeding from the tubal vessels, which become enlarged and engorged. The segment of the affected tube is distended as the pregnancy grows. Possible outcomes of such abnormal gestations are as follows:
The pregnancy is unable to survive owing to its poor blood supply, thus resulting in a tubal abortion and resorption , or it is expelled from the fimbriated end into the abdominal cavity.
The pregnancy continues to grow until the overdistended tube rupture s, with resulting profuse intraperitoneal bleeding.
In rare instances, a tubal pregnancy will be expelled from the tube and seed onto sites in the abdominal cavity (e.g. the omentum, the small or large bowel, or the parietal peritoneum), and gives rise to a viable abdominal pregnancy .
Symptoms and Clinical Diagnosis
High risk factors can be summarized as follows:
A history of tubal infection (ectopic rate of 1 in 24, as opposed to 1 in 200 in noninfected patients)
Prior ectopic pregnancy (15% to 50% increase in incidence of ectopic gestation in subsequent pregnancies)
History of tubal sterilization within the past 1 to 2 years (higher incidence if cauterization was used)
History of tubal reconstructive surgery (tuboplasty or end-to-end reanastomosis for sterilization reversal)
Pregnancy with an IUD in place or a history of IUD use.
More than one therapeutic abortion (controversial)
Pregnancy resulting from failed postcoital contraception (probably associated with abnormal tubal transport)
The classic symptom triad amenorrhea,
Abdominal pain, usually in the lower abdomen in early cases, or generalized in ruptured ectopics with a hemoperitoneum. Amenorrhea or a history of an abnormal last menstrual period is found in 75% to 90% of ectopic pregnancies. Vaginal bleeding, from spotting to the equivalent of a menstrual period, results from a low human chorionic gonadotropin (hCG) production by the ectopic trophoblast and is seen in 50% to 80% of patients.
Making the diagnosis of an acutely ruptured ectopic pregnancy is fairly straightforward. The patient presents with symptoms of increasing abdominal pain, abdominal distention, and hypovolemia. The entire abdomen is acutely tender with guarding and rebound tenderness.
Physical examination in patients with an unruptured ectopic pregnancy may be extremely variable. Ninety percent have abdominal tenderness, but only 45% have positive rebound tenderness, and only 50 % have an adnexal mass on pelvic examination. In half the cases, the mass is contralateral to the ectopic pregnancy and represents the corpus luteum. Twenty percent present with bilateral adnexal masses owing to the presence of a contralateral coupus luteum cyst. The uterus is soft and either of normal size or slightly enlarged.
Many gynecologic and nongynecologic disorders have symptoms in common with ectopic pregnancy. Gynecologic disorders to be considered include :
Threatened or incomplete abortion (also presenting with pain, bleeding, and a positive pregnancy test)
A ruptured corpus luteum cyst (abdominal pain, moderate to severe, at times coexisting with a history of amenorrhea, vaginal spotting, and presence or absence of pregnancy, and evidence of hemoperitoneum)
Acute pelvic inflammatory disease with fever, abdominal pain, leukocytosis, and, at times, adnexal masses.
Degenerating leiomyoma (common in pregnancy)
The key to the successful management of ectopic pregnancy is early diagnosis. Although the number of new cases has increased threefold, fewer are arriving at the hospital ruptured, with the patient already in hemorrhagic shock. This decrease is evidence that a high index of suspicion and vigorous efforts at early diagnosis are effective.
Human chorionic gonadotropin is consisting of two linked subunits, αandβ. β-hCG is secreted by both the cytotrophoblast and the syncytiotrophoblast and has the sole function of supporting the corpus luteum. Abnormalβ-hCG can not provide information on the location of the pregnancy. Ultrasonography must be used to locate the gestation.
The sensitivity of the current methods for detection of β-hCG in the maternal serum allows the confirmation of pregnancy even before a missed period.
This field has shown rapid technological improvements in recent years, and its application to the diagnosis of ectopic pregnancy, alone and in combination with hCG testing, is now the standard of care. Transvaginal ultrasonography has allowed the detection of an intrauterine gestational sac at as early as 5 weeks of amenorrhea (2 mm diameter).
If the sac is not visualized at the uterine cavity, special attention is needed to differentiate between a true sac and a pseudosac, which is a ring-like structure produced on ultrasound by a prominent decidual echo. Evidence of hemoperitoneum may be inferred by the sonographic description of “free fluid in the cul-de-sac.”
Culdocentesis is the technique by which a needle, attached to a syringe, is inserted transvaginally through the posterior vaginal fornix into the pouch of Douglas to detect any fluid within the peritoneal cavity (Fig. 2). Although the procedure is simple, inexpensive, and rapid, it is quite uncomfortable for the patient and is of limited use in an unruptured ectopic pregnancy. It is unnecessary when the diagnosis is obvious and has a high false-negative rate.
Fig. 2. Technique for culdocentesis
Immediate surgery is indicated when the diagnosis of ectopic pregnancy with hemorrhage is made. Transfusion with whole blood or an appropriate blood component therapy as soon possible is indicated when the patient is in shock.
Rapid entry into the abdomen should be accomplished, as control of hemorrhage can be lifesaving. Careful, fast exploration of the abdominal cavity should be done at once. Remove products of conception, clots, and free blood. At operation the damaged tube is usually removed. This procedure is the most common for ectopic pregnancy.
The type of procedure performed by either laparoscopy or laparotomy will be dictated by local findings at the time of surgery and the desire of the woman for future fertility. In patients who with to conserve fertility, a linear salpingostomy is the treatment of choice in unruptured ampullary pregnancies. In ampullary pregnancies that have already ruptured, a segmantal resection or partial salpingectomy can be offered, which implies the removal of only the affected segment of tube, leaving the rest intact.
Unruptured ectopic pregnancy can be treated with Methotrexate (MTX).
no contraidications to MTX
type of unruptured or abortion
unruptued mass <4 cm at its greastest dimension
β-hCG level <2000mIU/ml
without signs of hemoperitoneum
As many as 80% of ectopic pregnancies with hCG levels of 1000mIU/ml or less will not ruture spontaneously or bleed profusely but will undergo spontaneous resolution. Expectant management is generally reserved for reliable, relatively asymptomatic patients in whom the hCG titers are <200mIU/ml and delining.
Treatment of Uncommon Types of Ectopic Pregnancies
Ectopic pregnancy and tubal pregnancy are terms used interchangeably because other sites of ectopic implantation are rare. A pregnancy can implant on the surface of the ovary. The treatment is aimed at removing the pregnancy and sacrificing as little as possible of the ovarian tissue.
Cervical pregnancy usually presents with profuse vaginal bleeding, and attempts at removal of the pregnancy are often unsuccessful. Hysterectomy is frequently indicated and is usually quite difficult. In more recent years, methotrexate and arterial embolization have been used to manage cervical pregnancy.
All of the following therapeutic procedures are recommended for ectopic pregnancy EXCEPT:
C partial salpingectomy
Likely reasons for the establishment of an ectopic tubal pregnancy include all of the following EXCEPT: