ESSENTIALS OF DIAGNOSIS
Amenorrhea or irregular bleeding and spotting.
Pelvic pain, usually adnexal.
Adnexal mass by clinical examination or ultrasound.
Failure of serum beta-hCG to double every 48 hours.
No intrauterine pregnancy on transvaginal ultrasound with serum beta-hCG > 2000 milli-units/mL.
Ectopic implantation occurs in approximately 2% of first trimester pregnancies. About 98% of ectopic pregnancies are tubal. Other sites of ectopic implantation are the peritoneum or abdominal viscera, the ovary, and the cervix (eFigure 21–2). Any condition that prevents or inhibits migration of the fertilized ovum to the uterus can predispose to an ectopic pregnancy, including a history of infertility, pelvic inflammatory disease, ruptured appendix, and prior tubal surgery. Combined intrauterine and extrauterine pregnancy of two embryos (heterotopic) may occur rarely. In the United States, undiagnosed or undetected ectopic pregnancy is one of the most common causes of maternal death during the first trimester.
Various sites and frequency of ectopic pregnancies. (Reproduced, with permission, from Ectopic Pregnancy. In: Hoffman BL, Schorge JO, Halvorson LM, Hamid CA, Corton MM, Schaffer JI (editors). Williams Gynecology, 4th ed. McGraw Hill; 2020.)
Severe lower quadrant pain occurs in many cases. It is sudden in onset, stabbing, intermittent, and does not radiate. Backache may be present during attacks. Shock occurs in about 10%, often after pelvic examination. At least two-thirds of patients give a history of abnormal menstruation; many have been infertile.
Blood may leak from the tubal ampulla over a period of days, and considerable blood may accumulate in the peritoneum. Slight but persistent vaginal spotting is usually reported, and a pelvic mass may be palpated. Abdominal distention and mild paralytic ileus are often present.
The CBC may show anemia and slight leukocytosis. Quantitative serum pregnancy tests will show levels generally lower than expected for normal pregnancies of the same duration. If beta-hCG levels are followed over a few days, there may be a slow rise or a plateau rather than the near doubling every 2 days associated with normal early intrauterine pregnancy or the falling levels that occur with spontaneous abortion.
Ultrasonography can reliably demonstrate a gestational sac 5–6 weeks from the last menstruation and a fetal pole at 6 weeks if located in the uterus. An empty uterine cavity raises a strong suspicion of extrauterine pregnancy, which can occasionally be revealed by transvaginal ultrasound (eFigure 21–3). A discriminatory zone of serum beta-hCG (also known as a threshold level), has been correlated with ultrasound findings of an intrauterine pregnancy; a beta-hCG level of 6500 milli-units/mL with an empty uterine cavity ...