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Ectopic pregnancy is a complication of pregnancy in which the embryo attaches outside the
uterus The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...
. Signs and symptoms classically include
abdominal pain Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues. Common causes of pain in the abdomen include gastroenteritis and irritable bowel syndrome. About 15% of people have a m ...
and vaginal bleeding, but fewer than 50 percent of affected women have both of these symptoms. The pain may be described as sharp, dull, or crampy. Pain may also spread to the shoulder if bleeding into the abdomen has occurred. Severe bleeding may result in a
fast heart rate Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal (s ...
, fainting, or
shock Shock may refer to: Common uses Collective noun *Shock, a historic commercial term for a group of 60, see English numerals#Special names * Stook, or shock of grain, stacked sheaves Healthcare * Shock (circulatory), circulatory medical emerge ...
. With very rare exceptions the
fetus A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal dev ...
is unable to survive. Overall, ectopic pregnancies are very rare, annually affecting less than 2% of pregnancies worldwide. Risk factors for ectopic pregnancy include pelvic inflammatory disease, often due to chlamydia infection;
tobacco smoking Tobacco smoking is the practice of burning tobacco and ingesting the resulting smoke. The smoke may be inhaled, as is done with cigarettes, or simply released from the mouth, as is generally done with pipes and cigars. The practice is beli ...
; prior tubal surgery; a history of infertility; and the use of
assisted reproductive technology Assisted reproductive technology (ART) includes medical procedures used primarily to address infertility. This subject involves procedures such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), cryopreservation of gamet ...
. Those who have previously had an ectopic pregnancy are at much higher risk of having another one. Most ectopic pregnancies (90%) occur in the fallopian tube, which are known as tubal pregnancies, but implantation can also occur on the
cervix The cervix or cervix uteri (Latin, 'neck of the uterus') is the lower part of the uterus (womb) in the human female reproductive system. The cervix is usually 2 to 3 cm long (~1 inch) and roughly cylindrical in shape, which changes during ...
,
ovaries The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...
, caesarean scar, or within the
abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the to ...
. Detection of ectopic pregnancy is typically by blood tests for
human chorionic gonadotropin Human chorionic gonadotropin (hCG) is a hormone for the maternal recognition of pregnancy produced by trophoblast cells that are surrounding a growing embryo (syncytiotrophoblast initially), which eventually forms the placenta after implantatio ...
(hCG) and
ultrasound Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies ...
. This may require testing on more than one occasion. Ultrasound works best when performed from within the vagina. Other causes of similar symptoms include: miscarriage, ovarian torsion, and acute appendicitis. Prevention is by decreasing risk factors such as chlamydia infections through screening and treatment. While some ectopic pregnancies will miscarry without treatment, the standard treatment for ectopic pregnancy is an abortion. The use of the medication methotrexate works as well as surgery in some cases. Specifically it works well when the beta-HCG is low and the size of the ectopic is small. Surgery such as a salpingectomy is still typically recommended if the tube has ruptured, there is a fetal heartbeat, or the woman's vital signs are unstable. The surgery may be laparoscopic or through a larger incision, known as a
laparotomy A laparotomy is a surgical procedure involving a surgical incision through the abdominal wall to gain access into the abdominal cavity. It is also known as a celiotomy. Origins and history The first successful laparotomy was performed without ane ...
. Maternal morbidity and mortality are reduced with treatment. The rate of ectopic
pregnancy Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ...
is about 11 to 20 per 1,000 live births in developed countries, though it may be as high as 4% among those using
assisted reproductive technology Assisted reproductive technology (ART) includes medical procedures used primarily to address infertility. This subject involves procedures such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), cryopreservation of gamet ...
. It is the most common cause of death among women during the first trimester at approximately 6-13% of the total. In the developed world outcomes have improved while in the developing world they often remain poor. The risk of death among those in the developed world is between 0.1 and 0.3 percent while in the developing world it is between one and three percent. The first known description of an ectopic pregnancy is by
Al-Zahrawi Abū al-Qāsim Khalaf ibn al-'Abbās al-Zahrāwī al-Ansari ( ar, أبو القاسم خلف بن العباس الزهراوي;‎ 936–1013), popularly known as al-Zahrawi (), Latinised as Albucasis (from Arabic ''Abū al-Qāsim''), was ...
in the 11th century. The word "ectopic" means "out of place".


Signs and symptoms

Up to 10% of women with ectopic pregnancy have no symptoms, and one-third have no medical signs. In many cases the symptoms have low specificity, and can be similar to those of other genitourinary and gastrointestinal disorders, such as
appendicitis Appendicitis is inflammation of the appendix. Symptoms commonly include right lower abdominal pain, nausea, vomiting, and decreased appetite. However, approximately 40% of people do not have these typical symptoms. Severe complications of a r ...
,
salpingitis Salpingitis is an infection causing inflammation in the Fallopian tubes (also called ''salpinges''). It is often included in the umbrella term of pelvic inflammatory disease (PID), along with endometritis, oophoritis, myometritis, parametritis, an ...
, rupture of a corpus luteum cyst, miscarriage, ovarian torsion or urinary tract infection. Clinical presentation of ectopic pregnancy occurs at a mean of 7.2 weeks after the last normal menstrual period, with a range of four to eight weeks. Later presentations are more common in communities deprived of modern diagnostic ability. Signs and symptoms of ectopic pregnancy include increased hCG, vaginal bleeding (in varying amounts), sudden lower abdominal pain, pelvic pain, a tender cervix, an adnexal mass, or adnexal tenderness. In the absence of ultrasound or hCG assessment, heavy vaginal bleeding may lead to a misdiagnosis of miscarriage.
Nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of th ...
,
vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenter ...
and
diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...
are more rare symptoms of ectopic pregnancy. Rupture of an ectopic pregnancy can lead to symptoms such as abdominal distension, tenderness, peritonism and
hypovolemic shock Hypovolemic shock is a form of shock caused by severe hypovolemia (insufficient blood volume or extracellular fluid in the body). It could be the result of severe dehydration through a variety of mechanisms or blood loss. Hypovolemic shock is a ...
. A woman with ectopic pregnancy may be excessively mobile with upright posturing, in order to decrease intrapelvic blood flow, which can lead to swelling of the abdominal cavity and cause additional pain.


Complications

The most common complication is rupture with internal bleeding which may lead to hypovolemic shock. Damage to the fallopian tubes can lead to difficulty becoming pregnant in the future. The woman's other fallopian tube may function sufficiently for pregnancy. After the removal of one damaged fallopian tube, pregnancy remains possible in the future. If both are removed, in-vitro fertilization remains an option for women hoping to become pregnant.


Causes

There are a number of risk factors for ectopic pregnancies. However, in as many as one-third to one-half no risk factors can be identified. Risk factors include: pelvic inflammatory disease, infertility, use of an intrauterine device (IUD), previous exposure to
diethylstilbestrol Diethylstilbestrol (DES), also known as stilbestrol or stilboestrol, is a nonsteroidal estrogen medication, which is presently rarely used. In the past, it was widely used for a variety of indications, including pregnancy support for those with ...
(DES), tubal surgery, intrauterine surgery (e.g. D&C),
smoking Smoking is a practice in which a substance is burned and the resulting smoke is typically breathed in to be tasted and absorbed into the bloodstream. Most commonly, the substance used is the dried leaves of the tobacco plant, which have b ...
, previous ectopic pregnancy,
endometriosis Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus. Most often this is on the ovaries, fa ...
, and tubal ligation. A previous induced
abortion Abortion is the termination of a pregnancy by removal or expulsion of an embryo or fetus. An abortion that occurs without intervention is known as a miscarriage or "spontaneous abortion"; these occur in approximately 30% to 40% of pre ...
does not appear to increase the risk. The IUD does not increase the risk of ectopic pregnancy, but with an IUD if pregnancy occurs it is more likely to be ectopic than intrauterine. The risk of ectopic pregnancy after chlamydia infection is low. The exact mechanism through which chlamydia increases the risk of ectopic pregnancy is uncertain, though some research suggests that the infection can affect the structure of fallopian tubes.


Tube damage

Tubal pregnancy is when the egg is implanted in the fallopian tubes. Hair-like cilia located on the internal surface of the fallopian tubes carry the fertilized egg to the uterus. Fallopian cilia are sometimes seen in reduced numbers subsequent to an ectopic pregnancy, leading to a hypothesis that cilia damage in the fallopian tubes is likely to lead to an ectopic pregnancy. Women who smoke have a higher chance of an ectopic pregnancy in the fallopian tubes. Smoking leads to risk factors of damaging and destroying cilia. As cilia degenerate, the amount of time it takes for the fertilized egg to reach the uterus will increase. The fertilized egg, if it does not reach the uterus in time, will hatch from the non-adhesive zona pellucida and implant itself inside the fallopian tube, thus causing the ectopic pregnancy. Women with pelvic inflammatory disease (PID) have a high occurrence of ectopic pregnancy. This results from the build-up of scar tissue in the fallopian tubes, causing damage to cilia. However, if both tubes were completely blocked, so that sperm and egg were physically unable to meet, then fertilization of the egg would naturally be impossible, and neither normal pregnancy nor ectopic pregnancy could occur. Intrauterine adhesions (IUA) present in Asherman's syndrome can cause ectopic cervical pregnancy or, if adhesions partially block access to the tubes via the ostia, ectopic tubal pregnancy. Asherman's syndrome usually occurs from intrauterine surgery, most commonly after D&C. Endometrial/pelvic/genital
tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, ...
, another cause of Asherman's syndrome, can also lead to ectopic pregnancy as infection may lead to tubal adhesions in addition to intrauterine adhesions. Tubal ligation can predispose to ectopic pregnancy. Reversal of tubal sterilization ( tubal reversal) carries a risk for ectopic pregnancy. This is higher if more destructive methods of tubal ligation (tubal cautery, partial removal of the tubes) have been used than less destructive methods (tubal clipping). A history of a tubal pregnancy increases the risk of future occurrences to about 10%. This risk is not reduced by removing the affected tube, even if the other tube appears normal. The best method for diagnosing this is to do an early ultrasound.


Other

Although some investigations have shown that patients may be at higher risk for ectopic pregnancy with advancing age, it is believed that age is a variable which could act as a surrogate for other risk factors. Vaginal douching is thought by some to increase ectopic pregnancies. Women exposed to
DES Des is a masculine given name, mostly a short form (hypocorism) of Desmond. People named Des include: People * Des Buckingham, English football manager * Des Corcoran, (1928–2004), Australian politician * Des Dillon (disambiguation), sever ...
in utero (also known as "DES daughters") also have an elevated risk of ectopic pregnancy. However, DES has not been used since 1971 in the United States. It has also been suggested that pathologic generation of nitric oxide through increased
iNOS Nitric oxide synthases () (NOSs) are a family of enzymes catalyzing the production of nitric oxide (NO) from L-arginine. NO is an important cellular signaling molecule. It helps modulate vascular tone, insulin secretion, airway tone, and perista ...
production may decrease tubal ciliary beats and smooth muscle contractions and thus affect embryo transport, which may consequently result in ectopic pregnancy. The low socioeconomic status may be risk factors for ectopic pregnancy.


Diagnosis

An ectopic pregnancy should be considered as the cause of abdominal pain or vaginal bleeding in every woman who has a positive pregnancy test. The primary goal of diagnostic procedures in possible ectopic pregnancy is to triage according to risk rather than establishing pregnancy location.


Transvaginal ultrasonography

An
ultrasound Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies ...
showing a
gestational sac The gestational sac is the large cavity of fluid surrounding the embryo. During early embryogenesis it consists of the extraembryonic coelom, also called the chorionic cavity. The gestational sac is normally contained within the uterus. It is t ...
with fetal heart in the fallopian tube has a very high specificity of ectopic pregnancy. It involves a long, thin transducer, covered with the conducting gel and a plastic/latex sheath and inserted into the vagina.
Transvaginal ultrasonography Vaginal ultrasonography is a medical ultrasonography that applies an ultrasound transducer (or "probe") in the vagina to visualize organs within the pelvic cavity. It is also called transvaginal ultrasonography because the ultrasound waves go ' ...
has a sensitivity of at least 90% for ectopic pregnancy. The diagnostic ultrasonographic finding in ectopic pregnancy is an adnexal mass that moves separately from the ovary. In around 60% of cases, it is an inhomogeneous or a noncystic adnexal mass sometimes known as the "blob sign". It is generally spherical, but a more tubular appearance may be seen in case of hematosalpinx. This sign has been estimated to have a sensitivity of 84% and specificity of 99% in diagnosing ectopic pregnancy. In the study estimating these values, the blob sign had a
positive predictive value The positive and negative predictive values (PPV and NPV respectively) are the proportions of positive and negative results in statistics and diagnostic tests that are true positive and true negative results, respectively. The PPV and NPV des ...
of 96% and a
negative predictive value The positive and negative predictive values (PPV and NPV respectively) are the proportions of positive and negative results in statistics and diagnostic tests that are true positive and true negative results, respectively. The PPV and NPV des ...
of 95%. The visualization of an empty extrauterine gestational sac is sometimes known as the "bagel sign", and is present in around 20% of cases. In another 20% of cases, there is visualization of a gestational sac containing a yolk sac or an embryo. Ectopic pregnancies where there is visualization of cardiac activity are sometimes termed "viable ectopic". File:Schematic figure of vaginal ultrasound in ectopic pregnancy.png,
Transvaginal ultrasonography Vaginal ultrasonography is a medical ultrasonography that applies an ultrasound transducer (or "probe") in the vagina to visualize organs within the pelvic cavity. It is also called transvaginal ultrasonography because the ultrasound waves go ' ...
of an ectopic pregnancy, showing the field of view in the following image File:Blob sign of ectopic pregnancy.png, A "blob sign", which consists of the ectopic pregnancy. The ovary is distinguished from it by having follicles, whereof one is visible in the field. This patient had an intrauterine device (IUD) with progestogen, whose cross-section is visible in the field, leaving an ultrasound shadow distally to it. File:Ectopicleftmass.PNG, Ultrasound image showing an ectopic pregnancy where a
gestational sac The gestational sac is the large cavity of fluid surrounding the embryo. During early embryogenesis it consists of the extraembryonic coelom, also called the chorionic cavity. The gestational sac is normally contained within the uterus. It is t ...
and fetus has been formed
The combination of a positive pregnancy test and the presence of what appears to be a normal intrauterine pregnancy does not exclude an ectopic pregnancy, since there may be either a heterotopic pregnancy or a "", which is a collection of within the endometrial cavity that may be seen in up to 20% of women. A small amount of anechogenic-free fluid in the recto-uterine pouch is commonly found in both intrauterine and ectopic pregnancies. The presence of echogenic fluid is estimated at between 28 and 56% of women with an ectopic pregnancy, and strongly indicates the presence of hemoperitoneum. However, it does not necessarily result from tubal rupture but is commonly a result from leakage from the distal tubal opening. As a rule of thumb, the finding of free fluid is significant if it reaches the fundus or is present in the vesico-uterine pouch. A further marker of serious intra-abdominal bleeding is the presence of fluid in the hepatorenal recess of the subhepatic space. Currently,
Doppler ultrasonography Doppler ultrasonography is medical ultrasonography that employs the Doppler effect to perform imaging of the movement of tissues and body fluids (usually blood), and their relative velocity to the probe. By calculating the frequency shift of a ...
is not considered to significantly contribute to the diagnosis of ectopic pregnancy. A common misdiagnosis is of a normal intrauterine pregnancy is where the pregnancy is implanted laterally in an arcuate uterus, potentially being misdiagnosed as an interstitial pregnancy.


Ultrasonography and β-hCG

Where no intrauterine pregnancy (IUP) is seen on ultrasound, measuring β-human chorionic gonadotropin (β-hCG) levels may aid in the diagnosis. The rationale is that a low β-hCG level may indicate that the pregnancy is intrauterine but yet too small to be visible on ultrasonography. While some physicians consider that the threshold where an intrauterine pregnancy should be visible on transvaginal ultrasound is around 1500 mIU/mL of β-hCG, a review in the JAMA Rational Clinical Examination Series showed that there is no single threshold for the β-human chorionic gonadotropin that confirms an ectopic pregnancy. Instead, the best test in a pregnant woman is a high resolution transvaginal ultrasound. The presence of an adnexal mass in the absence of an intrauterine pregnancy on transvaginal sonography increases the likelihood of an ectopic pregnancy 100-fold (LR+ 111). When there are no adnexal abnormalities on transvaginal sonography, the likelihood of an ectopic pregnancy decreases (LR- 0.12). An empty uterus with levels higher than 1500 mIU/mL may be evidence of an ectopic pregnancy, but may also be consistent with an intrauterine pregnancy which is simply too small to be seen on ultrasound. If the diagnosis is uncertain, it may be necessary to wait a few days and repeat the blood work. This can be done by measuring the β-hCG level approximately 48 hours later and repeating the ultrasound. The serum hCG ratios and
logistic regression In statistics, the logistic model (or logit model) is a statistical model that models the probability of an event taking place by having the log-odds for the event be a linear combination of one or more independent variables. In regression an ...
models appear to be better than absolute single serum hCG level. If the β-hCG falls on repeat examination, this strongly suggests a spontaneous abortion or rupture. The fall in serum hCG over 48 hours may be measured as the hCG ratio, which is calculated as: hCG~ratio = \frac An hCG ratio of 0.87, that is, a decrease in hCG of 13% over 48 hours, has a sensitivity of 93% and specificity of 97% for predicting a failing pregnancy of unknown location (PUL). The majority of cases of ectopic pregnancy will have serial serum hCG levels that increase more slowly than would be expected with an IUP (that is, a ''suboptimal rise''), or decrease more slowly than would be expected with a failing PUL. However, up to 20% of cases of ectopic pregnancy have serum hCG doubling times similar to that of an IUP, and around 10% of EP cases have hCG patterns similar to a failing PUL.


Other methods


Direct examination

A laparoscopy or laparotomy can also be performed to visually confirm an ectopic pregnancy. This is generally reserved for women presenting with signs of an acute abdomen and
hypovolemic shock Hypovolemic shock is a form of shock caused by severe hypovolemia (insufficient blood volume or extracellular fluid in the body). It could be the result of severe dehydration through a variety of mechanisms or blood loss. Hypovolemic shock is a ...
. Often if a tubal abortion or tubal rupture has occurred, it is difficult to find the pregnancy tissue. A laparoscopy in very early ectopic pregnancy rarely shows a normal-looking fallopian tube.


Culdocentesis

Culdocentesis Culdocentesis is a medical procedure involving the extraction of fluid from the pouch of Douglas (a rectouterine pouch posterior to the vagina) through a needle. It can be one diagnostic technique used in identifying pelvic inflammatory disease (i ...
, in which fluid is retrieved from the space separating the vagina and rectum, is a less commonly performed test that may be used to look for internal bleeding. In this test, a needle is inserted into the space at the very top of the vagina, behind the uterus and in front of the rectum. Any blood or fluid found may have been derived from a ruptured ectopic pregnancy.


Progesterone levels

Progesterone levels of less than 20 nmol/L have a high
predictive value Predictive value of tests is the probability of a target condition given by the result of a test, often in regard to medical tests. *In cases where binary classification can be applied to the test results, such yes versus no, test target (such as ...
for failing pregnancies, whilst levels over 25 nmol/L are likely to predict viable pregnancies, and levels over 60 nmol/L are strongly so. This may help in identifying failing PUL that are at low risk and thereby needing less follow-up.
Inhibin A Activin and inhibin are two closely related protein complexes that have almost directly opposite biological effects. Identified in 1986, activin enhances FSH biosynthesis and secretion, and participates in the regulation of the menstrual ...
may also be useful for predicting spontaneous resolution of PUL, but is not as good as progesterone for this purpose.


Mathematical models

There are various mathematical models, such as logistic regression models and Bayesian networks, for the prediction of PUL outcome based on multiple parameters. Mathematical models also aim to identify PULs that are ''low risk'', that is, failing PULs and IUPs.


Dilation and curettage

Dilation and curettage Dilation (or dilatation) and curettage (D&C) refers to the dilation (widening/opening) of the cervix and surgical removal of part of the lining of the uterus and/or contents of the uterus by scraping and scooping ( curettage). It is a gynecologi ...
(D&C) is sometimes used to diagnose pregnancy location with the aim of differentiating between an EP and a non-viable IUP in situations where a viable IUP can be ruled out. Specific indications for this procedure include either of the following: * No visible IUP on transvaginal ultrasonography with a serum hCG of more than 2000 mIU/mL. * An abnormal rise in hCG level. A rise of 35% over 48 hours is proposed as the minimal rise consistent with a viable intrauterine pregnancy. * An abnormal fall in hCG level, such as defined as one of less than 20% in two days.


Classification


Tubal pregnancy

The vast majority of ectopic pregnancies implant in the fallopian tube. Pregnancies can grow in the fimbrial end (5% of all ectopic pregnancies), the ampullary section (80%), the isthmus (12%), and the cornual and interstitial part of the tube (2%). Mortality of a tubal pregnancy at the isthmus or within the uterus (interstitial pregnancy) is higher as there is increased vascularity that may result more likely in sudden major internal bleeding. A review published in 2010 supports the hypothesis that tubal ectopic pregnancy is caused by a combination of retention of the embryo within the fallopian tube due to impaired embryo-tubal transport and alterations in the tubal environment allowing early implantation to occur.


Nontubal ectopic pregnancy

Two percent of ectopic pregnancies occur in the ovary, cervix, or are intra-abdominal. Transvaginal ultrasound examination is usually able to detect a cervical pregnancy. An ovarian pregnancy is differentiated from a tubal pregnancy by the Spiegelberg criteria. While a fetus of ectopic pregnancy is typically not viable, very rarely, a live baby has been delivered from an abdominal pregnancy. In such a situation the
placenta The placenta is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas and waste exchange between the physically separate mate ...
sits on the intra-abdominal organs or the
peritoneum The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mes ...
and has found sufficient blood supply. This is generally bowel or mesentery, but other sites, such as the renal (kidney), liver or hepatic (liver) artery or even aorta have been described. Support to near viability has occasionally been described, but even in
Third World The term "Third World" arose during the Cold War to define countries that remained non-aligned with either NATO or the Warsaw Pact. The United States, Canada, Japan, South Korea, Western European nations and their allies represented the " First ...
countries, the diagnosis is most commonly made at 16 to 20 weeks' gestation. Such a fetus would have to be delivered by laparotomy. Maternal morbidity and mortality from extrauterine pregnancy are high as attempts to remove the placenta from the organs to which it is attached usually lead to uncontrollable bleeding from the attachment site. If the organ to which the placenta is attached is removable, such as a section of bowel, then the placenta should be removed together with that organ. This is such a rare occurrence that true data is unavailable and reliance must be made on anecdotal reports. However, the vast majority of abdominal pregnancies require intervention well before
fetal viability Fetal viability is the ability of a human fetus to survive outside the uterus. Medical viability is generally considered to be between 23 and 24 weeks gestational age. Viability depends upon factors such as birth weight, gestational age, and the ...
because of the risk of bleeding. With the increase in Cesarean sections performed worldwide, Cesarean section ectopic pregnancies (CSP) are rare, but becoming more common. The incidence of CSP is not well known, however there have been estimates based on different populations of 1:1800–1:2216. CSP are characterized by abnormal implantation into the scar from a previous cesarean section, and allowed to continue can cause serious complications such as uterine rupture and hemorrhage. Patients with CSP generally present without symptoms, however symptoms can include vaginal bleeding that may or may not be associated with pain. The diagnosis of CSP is made by ultrasound and four characteristics are noted: (1) Empty uterine cavity with bright hyperechoic endometrial stripe (2) Empty cervical canal (3) Intrauterine mass in the anterior part of the uterine isthmus, and (4) Absence of the anterior uterine muscle layer, and/or absence or thinning between the bladder and gestational sac, measuring less than 5 mm. Given the rarity of the diagnosis, treatment options tend to be described in case reports and series, ranging from medical with methotrexate or KCl to surgical with dilation and curettage, uterine wedge resection, or hysterectomy. A double-balloon catheter technique has also been described, allowing for uterine preservation. Recurrence risk for CSP is unknown, and early ultrasound in the next pregnancy is recommended.


Heterotopic pregnancy

In rare cases of ectopic pregnancy, there may be two fertilized eggs, one outside the uterus and the other inside. This is called a heterotopic pregnancy. Often the intrauterine pregnancy is discovered later than the ectopic, mainly because of the painful emergency nature of ectopic pregnancies. Since ectopic pregnancies are normally discovered and removed very early in the pregnancy, an ultrasound may not find the additional pregnancy inside the uterus. When hCG levels continue to rise after the removal of the ectopic pregnancy, there is the chance that a pregnancy inside the uterus is still viable. This is normally discovered through an ultrasound. Although rare, heterotopic pregnancies are becoming more common, likely due to increased use of IVF. The survival rate of the uterine fetus of a heterotopic pregnancy is around 70%.


Persistent ectopic pregnancy

A persistent ectopic pregnancy refers to the continuation of trophoblastic growth after a surgical intervention to remove an ectopic pregnancy. After a conservative procedure that attempts to preserve the affected fallopian tube such as a salpingotomy, in about 15–20% the major portion of the ectopic growth may have been removed, but some trophoblastic tissue, perhaps deeply embedded, has escaped removal and continues to grow, generating a new rise in hCG levels. After weeks this may lead to new clinical symptoms including bleeding. For this reason hCG levels may have to be monitored after removal of an ectopic pregnancy to assure their decline, also methotrexate can be given at the time of surgery prophylactically.


Pregnancy of unknown location

Pregnancy of unknown location (PUL) is the term used for a pregnancy where there is a positive pregnancy test but no pregnancy has been visualized using transvaginal ultrasonography. Specialized early pregnancy departments have estimated that between 8% and 10% of women attending for an ultrasound assessment in early pregnancy will be classified as having a PUL. The true nature of the pregnancy can be an ongoing viable intrauterine pregnancy, a failed pregnancy, an ectopic pregnancy or rarely a persisting PUL. Because of frequent ambiguity on ultrasonography examinations, the following classification is proposed: In women with a pregnancy of unknown location, between 6% and 20% have an ectopic pregnancy. In cases of pregnancy of unknown location and a history of heavy bleeding, it has been estimated that approximately 6% have an underlying ectopic pregnancy. Between 30% and 47% of women with pregnancy of unknown location are ultimately diagnosed with an ongoing intrauterine pregnancy, whereof the majority (50–70%) will be found to have failing pregnancies where the location is never confirmed. is where the hCG level does not spontaneously decline and no intrauterine or ectopic pregnancy is identified on follow-up transvaginal ultrasonography. A persisting PUL is likely either a small ectopic pregnancy that has not been visualized, or a retained trophoblast in the endometrial cavity. Treatment should only be considered when a potentially viable intrauterine pregnancy has been definitively excluded. A ''treated persistent PUL'' is defined as one managed medically (generally with methotrexate) without confirmation of the location of the pregnancy such as by ultrasound, laparoscopy or uterine evacuation. A ''resolved persistent PUL'' is defined as serum hCG reaching a non-pregnant value (generally less than 5 IU/L) after expectant management, or after uterine evacuation without evidence of chorionic villi on histopathological examination. In contrast, a relatively low and unresolving level of serum hCG indicates the possibility of an hCG-secreting tumour.


Differential diagnosis

Other conditions that cause similar symptoms include: miscarriage, ovarian torsion, and acute appendicitis, ruptured ovarian cyst, kidney stone, and pelvic inflammatory disease, among others.


Treatment


Expectant management

Most women with a PUL are followed up with serum hCG measurements and repeat TVS examinations until a final diagnosis is confirmed. Low-risk cases of PUL that appear to be failing pregnancies may be followed up with a urinary pregnancy test after two weeks and get subsequent telephone advice. Low-risk cases of PUL that are likely intrauterine pregnancies may have another TVS in two weeks to access viability. High-risk cases of PUL require further assessment, either with a TVS within 48 h or additional hCG measurement.


Medical

Early treatment of an ectopic pregnancy with methotrexate is a viable alternative to surgical treatment which was developed in the 1980s. If administered early in the pregnancy, methotrexate terminates the growth of the developing embryo; this may cause an abortion, or the developing embryo may then be either resorbed by the woman's body or pass with a menstrual period. Contraindications include liver, kidney, or blood disease, as well as an ectopic embryonic mass > 3.5 cm. Also, it may lead to the inadvertent termination of an undetected intrauterine pregnancy, or severe abnormality in any surviving pregnancy. Therefore, it is recommended that methotrexate should only be administered when hCG has been serially monitored with a rise less than 35% over 48 hours, which practically excludes a viable intrauterine pregnancy. For nontubal ectopic pregnancy, evidence from randomised clinical trials in women with CSP is uncertain regarding treatment success, complications and side effects of methotrexate compared with surgery ( uterine arterial embolization or uterine arterial chemoembolization). The United States uses a multi dose protocol of methotrexate (MTX) which involves four doses of intramuscular along with an intramuscular injection of folinic acid to protect cells from the effects of the drugs and to reduce side effects. In France, the single dose protocol is followed, but a single dose has a greater chance of failure.


Surgery

If bleeding has already occurred, surgical intervention may be necessary. However, whether to pursue surgical intervention is an often difficult decision in a stable patient with minimal evidence of blood clot on ultrasound. Surgeons use laparoscopy or laparotomy to gain access to the pelvis and can either incise the affected Fallopian tube and remove only the pregnancy (
salpingostomy Salpingectomy refers to the surgical removal of a Fallopian tube. This may be done to treat an ectopic pregnancy or cancer, to prevent cancer, or as a form of contraception. This procedure is now sometimes preferred over its ovarian tube-sparin ...
) or remove the affected tube with the pregnancy ( salpingectomy). The first successful surgery for an ectopic pregnancy was performed by Robert Lawson Tait in 1883. It is estimated that an acceptable rate of PULs that eventually undergo surgery is between 0.5 and 11%. People that undergo salpingectomy and salpingostomy have a similar recurrent ectopic pregnancy rate of 5% and 8% respectively. Additionally, their intrauterine pregnancy rates are also similar, 56% and 61%. Autotransfusion of a woman's own blood as drained during surgery may be useful in those who have a lot of bleeding into their abdomen. Published reports that a re-implanted embryo survived to birth were debunked as false.


Prognosis

When ectopic pregnancies are treated, the prognosis for the mother is very good in Western countries; maternal death is rare, but all fetuses die or are aborted. For instance, in the UK, between 2003 and 2005 there were 32,100 ectopic pregnancies resulting in 10 maternal deaths (meaning that 1 in 3,210 women with an ectopic pregnancy died). In 2006–2008 the UK Confidential Enquiry into Maternal Deaths found that ectopic pregnancy is the cause of 6 maternal deaths (0.26/100,000 pregnancies). In the developing world, however, especially in Africa, the death rate is very high, and ectopic pregnancies are a major cause of death among women of childbearing age. In women having had an ectopic pregnancy, the risk of another one in the next pregnancy is around 10%.


Future fertility

Fertility following ectopic pregnancy depends upon several factors, the most important of which is a prior history of infertility. The treatment choice does not play a major role; a randomized study in 2013 concluded that the rates of intrauterine pregnancy two years after treatment of ectopic pregnancy are approximately 64% with radical surgery, 67% with medication, and 70% with conservative surgery. In comparison, the cumulative pregnancy rate of women under 40 years of age in the general population over two years is over 90%.Fertility: assessment and treatment for people with fertility problems
. NICE clinical guideline CG156 – Issued: February 2013
Methotrexate does not affect future fertility treatments. The number of oocytes that were retrieved before and after treatment with methotrexate does not change. In case of ovarian ectopic pregnancy, the risk of subsequent ectopic pregnancy or infertility is low. There is no evidence that massage improves fertility after ectopic pregnancy.


Epidemiology

The rate of ectopic pregnancy is about 1% and 2% of that of live births in developed countries, though it is as high as 4% in pregnancies involving assisted reproductive technology. Between 93% and 97% of ectopic pregnancies are located in a fallopian tube. Of these, in turn, 13% are located in the isthmus, 75% are located in the ampulla, and 12% in the fimbriae. Ectopic pregnancy is responsible for 6% of maternal deaths during the first trimester of pregnancy making it the leading cause of maternal death during this stage of pregnancy. Between 5% and 42% of women seen for ultrasound assessment with a positive pregnancy test have a pregnancy of unknown location, that is a positive pregnancy test but no pregnancy visualized at transvaginal ultrasonography. Between 6% and 20% of pregnancy of unknown location are subsequently diagnosed with actual ectopic pregnancy.


Society and culture

Salpingectomy as a treatment for ectopic pregnancy is one of the common cases when the principle of double effect can be used to justify accelerating the death of the embryo by doctors and patients opposed to outright abortions. In the
Catholic Church The Catholic Church, also known as the Roman Catholic Church, is the List of Christian denominations by number of members, largest Christian church, with 1.3 billion baptized Catholics Catholic Church by country, worldwide . It is am ...
, there are moral debates on certain treatments. A significant number of Catholic moralists consider use of methotrexate and the salpingostomy procedure to be not "morally permissible" because they destroy the embryo; however, situations are considered differently in which the mother's health is endangered, and the whole fallopian tube with the developing embryo inside is removed. Organisations exist that provide information and support to help those who experience ectopic pregnancy. Studies show that people can experience post-traumatic stress, depression, and anxiety for which they would need specialist therapies. Partners can also experience post-traumatic stress.


Live birth

There have been cases where ectopic pregnancy lasted many months and ended in a live baby delivered by laparotomy. In July 1999, Lori Dalton gave birth by caesarean section in Ogden, Utah, United States, to a healthy baby girl, Saige, who had developed outside of the uterus. Previous ultrasounds had not discovered the problem. " altons delivery was slated as a routine Caesarean birth at Ogden Regional Medical Center in Utah. When Dr. Naisbitt performed Lori's Caesarean, he was astonished to find Saige within the amniotic membrane outside the womb ... ." "But what makes this case so rare is that not only did mother and baby survive—they're both in perfect health. The father, John Dalton took home video inside the delivery room. Saige came out doing extremely well because even though she had been implanted outside the womb, a rich blood supply from a uterine fibroid along the outer uterus wall had nourished her with a rich source of blood." In September 1999 an English woman, Jane Ingram (age 32) gave birth to triplets: Olivia, Mary and Ronan, with an extrauterine fetus (Ronan) below the womb and twins in the womb. All three survived. The twins in the womb were taken out first. On May 29, 2008, an Australian woman, Meera Thangarajah (age 34), who had an ectopic pregnancy in the
ovary The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. ...
, gave birth to a healthy full term 6 pound 3 ounce (2.8 kg) baby girl, Durga, via Caesarean section. She had no problems or complications during the 38‑week pregnancy.


Animals

Ectopic gestation exists in
mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur ...
s other than humans. In
sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticate ...
, it can go to term, with mammary preparation to parturition, and expulsion efforts. The fetus can be removed by caesarean section. Pictures of caesarian section of a euthanized ewe, five days after parturition signs. File:Poirtêye foû matrice pate.JPG, Leg of fetal lamb appearing out of the uterus during caesarean section File:Poirtêye foû matrice saetch1.JPG, External view of fetal sac, necrotic distal part File:Poirtêye foû matrice saetch2.JPG, Internal view of fetal sac, before resection of distal necrotic part File:Poirtêye foû matrice saetch3.JPG, Internal view of fetal sac. The necrotic distal part is to the left. File:Poirtêye foû matrice saetch&coine.JPG, External side of fetal sac, proximal end, with ovary and uterine horn File:Poirtêye foû matrice saetch ådfoû pwels.JPG, Resected distal part of fetal sac, with attached placenta


See also

* Indirect abortion


References


External links


CT of the abdomen showing abdominal ectopic pregnancy
{{Authority control Wikipedia articles with sections published in WikiJournal of Medicine Medical emergencies Health issues in pregnancy Wikipedia medicine articles ready to translate Acute pain