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Ectopic pregnancy: Epidemiology, risk factors, and anatomic sites

Togas Tulandi, MD, MHCM
Section Editor
Courtney A Schreiber, MD, MPH
Deputy Editor
Sandy J Falk, MD, FACOG


Ectopic pregnancy is a pregnancy in which the developing blastocyst becomes implanted at a site other than the endometrium of the uterine cavity. The most common extrauterine location is the fallopian tube, which accounts for 96 percent of all ectopic gestations (picture 1A-B). Management of these pregnancies has changed dramatically over the years [1]. Preferred management is pharmacologic treatment with methotrexate, rather than surgery. It is important to remember, however, that hemorrhage from ectopic pregnancy is still the leading cause of pregnancy-related maternal mortality in the first trimester and accounts for 4 percent of all pregnancy-related deaths, despite improved diagnostic methods leading to earlier detection and treatment [2,3].

The epidemiology, risk factors, and anatomic sites of ectopic pregnancy will be reviewed here. Related topics regarding ectopic pregnancy are discussed in detail separately, including:

Clinical manifestations and diagnosis (see "Ectopic pregnancy: Clinical manifestations and diagnosis")

Choosing a treatment approach (see "Ectopic pregnancy: Choosing a treatment")

Methotrexate therapy (see "Ectopic pregnancy: Methotrexate therapy")

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Literature review current through: Nov 2017. | This topic last updated: Nov 14, 2017.
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