A heterotopic pregnancy is a

complication of pregnancy Complications of pregnancy are health problems that are related to pregnancy. Complications that occur primarily during childbirth are termed obstetric labor complications, and problems that occur primarily after childbirth are termed puerperal di ...

in which both extrauterine ( ectopic) pregnancy and

intrauterine 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 uter ...

pregnancy Pregnancy is the time during which one or more offspring develops (gestation, gestates) inside a woman, woman's uterus (womb). A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occur ...

occur simultaneously. It may also be referred to as a combined ectopic pregnancy, multiple‑sited pregnancy, or coincident pregnancy. The most common site of the extrauterine pregnancy is the fallopian tube. However, other sites of implantation include the cervix, ovary, and abdomen. Although heterotopic pregnancies were once thought to be a rare phenomenon, the incidence has increased due to the increasing use of assisted reproductive technologies.

Cause

In a heterotopic pregnancy there is one fertilized ovum which implants normally in the uterus, and one fertilized ovum which implants abnormally, outside of the uterus.

Pathogenesis

In the general population, the major risk factors for heterotopic pregnancy are the same as those for ectopic pregnancy: * Previous history of ectopic pregnancy * Tubal surgery * Pelvic inflammatory disease * Use of an intrauterine device * In utero diethylstilbestrol exposure * Smoking Women participating in an assisted reproductive program have an increased risk of heterotopic pregnancy for several reasons including: * Higher incidence of ovulation due to treatment * Multiple embryo transfers * Technical factors in embryo transfer which may increase the risk for ectopic and heterotopic pregnancy * Higher incidence of tubal malformation and/or tubal damage in this group * Higher levels of estradiol and progesterone due to hormonal treatment

Diagnosis

Signs and symptoms

Heterotopic pregnancies present with unspecific clinical symptoms. This means the symptoms of a heterotopic pregnancy can be the same symptoms found in several other medical conditions. The most common clinical symptoms are

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 ...

vaginal bleeding Vaginal bleeding is any expulsion of blood from the vagina. This bleeding may originate from the uterus, vaginal wall, or cervix. Generally, it is either part of a normal menstrual cycle or is caused by hormonal or other problems of the reproductiv ...

, enlarged uterus, and/or an

adnexal mass In anatomy, adnexa (plural) refers to the appendage An appendage (or outgrowth) is an external body part, or natural prolongation, that protrudes from an organism's body. In arthropods, an appendage refers to any of the homologous body parts ...

. The vague symptoms found in heterotopic pregnancies can contribute to the delayed diagnosis of this condition, which can lead to devastating consequences, including a ruptured ectopic pregnancy.

Differential diagnosis

The signs and symptoms of a heterotopic pregnancy can be found in many other gynecological and non-gynecological conditions, including: *

Ovarian torsion Ovarian torsion (OT) or adnexal torsion is an abnormal condition where an ovary twists on its attachment to other structures, such that blood flow is decreased. Symptoms typically include pelvic pain on one side. While classically the pain is sud ...

Ovarian cyst An ovarian cyst is a fluid-filled sac within the ovary. Often they cause no symptoms. Occasionally they may produce bloating, lower abdominal pain, or lower back pain. The majority of cysts are harmless. If the cyst either breaks open or causes ...

* Threatened abortion *

Urinary tract infection A urinary tract infection (UTI) is an infection that affects part of the urinary tract. When it affects the lower urinary tract it is known as a bladder infection (cystitis) and when it affects the upper urinary tract it is known as a kidne ...

Kidney stones Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a calculus (medicine), solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the ...

Constipation Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement ...

* Diverticulitis * Pelvic inflammatory disease * Bowel obstruction * Inflammatory bowel disease

Ultrasound

The gold standard for diagnosing a heterotopic pregnancy is the

transvaginal ultrasound 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 ''a ...

. However, the sensitivity of the transvaginal ultrasound for diagnosing a heterotopic pregnancy has been found to range from 26.3% to 92.4%. Therefore, both clinical symptoms and ultrasound imaging are used to make the diagnosis.

Management

The goal of treatment is to preserve the viable intrauterine pregnancy and to remove the nonviable ectopic pregnancy. The standard surgical approach for removal of the nonviable ectopic pregnancy is by

salpingectomy 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 salpingostomy. In the case of an unruptured ectopic pregnancy, local feticidal injection can be used to remove the ectopic pregnancy. For this method, ultrasound is used to guide a needle to the ectopic pregnancy and substances such as potassium chloride and hyperosmolar glucose are injected directly into the gestational sac. The use of this method can be limited due the location of the ectopic pregnancy and the experience of the physician with this technique. Treatment of heterotopic pregnancy will depend on the specific location of the ectopic pregnancy, as well as the pregnant person's clinical presentation and stability.

Prognosis

Extrauterine pregnancies are non-viable and can be fatal to the mother if left untreated. However, successfully continuing the intrauterine pregnancy following removal of the extrauterine is possible and has a success rate of about 50 to 66%.

Epidemiology

The

prevalence In epidemiology, prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seatbelt use) at a specific time. It is derived by comparing the number o ...

of heterotopic pregnancy is estimated at 0.6‑2.5:10,000 pregnancies. There is a significant increase in the incidence of heterotopic pregnancy in women undergoing

ovulation induction Ovulation induction is the stimulation of ovulation by medication. It is usually used in the sense of stimulation of the development of ovarian follicles Ovulation Induction Retrieved on Mars 7, 2010 to reverse anovulation or oligoovulation. S ...

. An even greater incidence of heterotopic pregnancy is reported in pregnancies following

assisted reproduction 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 gametes ...

techniques such as

In vitro fertilization In vitro fertilisation (IVF) is a process of fertilisation where an egg is combined with sperm in vitro ("in glass"). The process involves monitoring and stimulating an individual's ovulatory process, removing an ovum or ova (egg or eggs) f ...

(IVF) and gamete intrafallopian transfer (GIFT), with an estimated incidence at between 1 and 3 in 100 pregnancies. If there is

embryo transfer Embryo transfer refers to a step in the process of assisted reproduction in which embryos are placed into the uterus of a female with the intent to establish a pregnancy. This technique (which is often used in connection with in vitro fertilizati ...

of more than 4 embryos, the risk has been quoted as 1 in 45. In natural conceptions, the incidence of heterotopic pregnancy has been estimated to be 1 in 30,000 pregnancies. However, due to the increasing use of assisted reproduction technology, the overall incidence is 1 in 3900 pregnancies.

References

External links

{{Authority control Health issues in pregnancy Ectopic pregnancy