A pregnancy implanted in an abnormal location, such as the fallopian tube (see tubal pregnancy), the cervix (see cervical pregnancy), the ovary (see ovarian pregnancy) or the peritoneal cavity (see abdominal pregnancy).

The percentage of ectopic pregnancies among total clinical pregnancies (excluding "biochemical pregnancy"). Until a generation ago, the rate was about 0.3 percent, and this can be regarded as the incidence in normal women. The rate is increased with abnormalities of the fallopian tubes, assisted conception, and other circumstances, so that nowadays ectopic pregnancies account for about 2 percent of pregnancies in western societies.

An ectopic pregnancy located in the peritoneal cavity, or abdomen, usually having undergone implantation in the fallopian tube as a tubal pregnancy, then continuing to grow after the tube eventually ruptures. Rare in countries with ready access to medical care, as considerable symptoms have to have been ignored (and survived) during the tubal rupture part of the process. The fetus can grow almost to full term, but delivery of a live baby (delivered by operation) has never been reported.

Most commonly done before an operation that could cause significant loss of blood, especially if an ectopic pregnancy is suspected, because a blood transfusion might be needed. Also done for investigation of recurrent miscarriages, when the rare but important antibody anti-TjA needs to be excluded or detected. Rh-negative women who have a Rh-positive partner who are treated for miscarriage or for ectopic pregnancy often require an injection of Rhogam or anti-D gamma globulin to avoid being sensitised (developing antibodies to) possibly Rh Positive red blood cells from the embryo or fetus.

An ectopic pregnancy located in the wall of the cervix. A particularly dangerous condition because of the risk of uncontrollable bleeding.

The coexistence of a pregnancy in the uterus with an ectopic pregnancy.

An ectopic pregnancy located in the interstitial segment of the fallopian tube. An especially dangerous form of tubal pregnancy, because the surrounding myometrium of the uterus supports the pregnancy's growth for weeks without causing symptoms; when rupture eventually occurs it can be catastrophic, because a main branch of the main artery to the uterus is torn, with sudden (sometimes fatal) bleeding into the peritoneal cavity.

A cytotoxic drug, originally developed for chemotherapy for certain cancers, used in the treatment of ectopic pregnancy, especially in the US; side effects can include bone marrow depression, gastrointestinal upset and mouth ulcers, and other effects.

An ectopic pregnancy located in the substance of the ovary, presumably because an egg (an oocyte has been fertilised while still in a follicle).

Using a contraceptive after sex instead of before it, to interrupt implantation of an embryo (if there is one). Taking two birth control (oral contraceptive) pills the morning and the night after the unanticipated opportunity for pregnancy is reasonably effective, but see your physician for details to carry this out safely and effectively. This maneuver might not protect against an ectopic pregnancy.

The percentage of months or treatment cycles that result in clinical pregnancy, excluding biochemical pregnancy, but including ectopic pregnancy, miscarriage and all potentially viable pregnancies (twins are not counted twice; stillbirths and all live births are included). Less important for most patients' purposes than the take-home-baby rate. Less useful for embryologists intent on quality control in the laboratory than the implantation rate.

Nowadays a measurement of human chorionic gonadotropin in serum or urine, usually as a simple 'yes' or 'no' test. In principle a single test cannot distinguish a normal pregnancy from an ectopic pregnancy or one destined to miscarry (a miscarriage).

Trouble getting pregnant (infertility) in someone who has never had a successful pregnancy. Although the exact definition can vary among gynecologists, the differentiation between primary infertility and secondary infertility is most useful if a prior ectopic pregnancy or a prior miscarriage is consistent with the state of primary infertility, whereas a prior induced abortion (which, the odds are, would otherwise have developed normally) means the state is secondary infertility.

A nodular ('nodosa') thickening of the fallopian tube's isthmus ('isthmica'), probably due to previous salpingitis. Can cause localised obstruction of the tube and, if the obstruction is partial, an ectopic pregnancy can be caused. Overcomeable with microsurgery or tubal canalisation.

An operation involving a temporary opening length-wise along (usually) the ampulla of the fallopian tube, usually for the treatment of a (tubal) ectopic pregnancy. Occasionally performed for a pyosalpinx. Can be carried out efficiently at laparoscopy.

Trouble getting pregnant (infertility) in someone who has previously had a successful or potentially successful pregnancy. Although the exact definition of secondary infertility can vary among gynecologists, for me the distinction between secondary infertility and primary infertility is most useful if the term secondary infertility is restricted to when there has been a prior induced abortion (which, the odds are, would otherwise have developed normally) or a successful pregnancy; a prior ectopic pregnancy or a prior miscarriage is, in my view, still the state of primary infertility.

Measurement of human chorionic gonadotropin in serum: essentially a pregnancy test, but carried out more precisely (quantitatively) than is the case with a yes or no test (which is qualitative). Often carried out serially, to determine if a pregnancy is: thriving (hCG levels double every two or three days in normal early pregnancy; languishing (levels rise more slowly, seen with an ectopic pregnancy and with an inevitable miscarriage); or resolving naturally (levels that are falling). Very high levels are seen with hydatidiform mole. Part of the triple screen used to screen for Down syndrome in early pregnancy.

A tubal ectopic pregnancy that is in the process of being expelled out the fimbrial end of the fallopian tube.

An ectopic pregnancy located in the fallopian tube; most occur in the ampulla, but others can be located in the narrower isthmus or in the interstitial segment.