ECTOPIC PREGNANCY

INTRODUCTION: An ectopic or extrauterine pregnancy is one in which the blastocyst implants anywhere other than the endometrial lining of the uterine cavity. Ectopic pregnancies account for less than 5% on average. In most cases, 98% of ectopic pregnancies implant in the fallopian tube, with 80% occurring in the ampullary segment. Other locations include, but are not limited to, the ovary, cervix, and abdomen.

TUBAL ECTOPIC PREGNANCY: Without intervention, the natural course of a tubal pregnancy will result in any of three outcomes: tubal abortion, tubal rupture, or spontaneous resolution. Tubal abortion is the expulsion of the pregnancy through the fimbriated end. This tissue can then either regress or reimplant in the abdominal cavity. Tubal rupture is associated with significant intraabdominal hemorrhage, often necessitating surgical intervention.

PATHOPHYSIOLOGY AND RISK FACTORS: Inflammation resulting in tubal damage can disrupt the normal migration of a fertilized ovum through the tube, thereby predisposing to an ectopic pregnancy. Specific examples of an inflammatory process include salpingitis.  An acute chlamydial infection causes intraluminal inflammation and subsequent fibrin deposition with tubal scarring. Whereas endotoxin-producing Neisseria gonorrhoeae causes virulent pelvic inflammation with a rapid clinical onset, chlamydial inflammatory response has a bit slow onset and peaks at 7 to 14 days.

The incidence of ectopic pregnancy has increased consistently with the rise in chlamydial infections. Pregnancy after tubal sterilization is rare, but, when it does occur, there is a substantial risk that the pregnancy will be ectopic due to the distorted tubal anatomy created by the tubal ligation.  Additional risk factors include prior ectopic pregnancy, smoking, prior tubal surgery, and advanced age.

SYMPTOMS: The classic symptoms associated with ectopic pregnancy are amenorrhea followed by vaginal bleeding and abdominal pain on the affected side; however, there is no constellation of symptoms that are diagnostic. Normal pregnancy symptoms, such as breast tenderness, nausea, and urinary frequency, may accompany more ominous findings. These include shoulder pain worsened by inspiration. As long as placental hormones are produced, there is usually no vaginal bleeding. Irregular vaginal bleeding results from the sloughing of the decidua from the endometrial lining.

Vaginal bleeding in patients with an ectopic gestation may range from little or none to heavy, menstrual-like flow. In some patients, the entire “decidual cast” is passed intact, simulating a spontaneous abortion.  In any pregnant patient with no histopathologic confirmation of chorionic villi within the uterus, an ectopic implantation should be assumed to be present until proven otherwise.

RELATED;

1.  PRETERM LABOR AND BIRTH

2.  PARTURITION AND LABOR

3.  RHESUS DISEASE OF THE NEWBORN

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