- Habitual abortion
Habitual abortion, recurrent miscarriage or recurrent pregnancy loss (RPL) is the occurrence of repeated (three or more consecutive) pregnancies that end in
miscarriageof the fetus, usually before 20 weeks of gestation. RPL affects about 0.34%cite web |url=http://www.rcog.org.uk/resources/Public/pdf/Recurrent_Miscarriage_No17.pdf |title=The Investigation and Treatment of Couples with Recurrent Miscarriage: Guideline No 17 |format=PDF |publisher=Royal College of Obstetricians and Gynaecologists |accessdate=] of women who conceive.
The majority (85%) of women who have had two miscarriages will conceive and carry normally afterwards, so statistically the occurrence of three abortions at 0.34% is regarded as "habitual".
There are various causes for habitual abortions, and some are treatable. Some couples never have a cause identified, often after extensive investigations.
uterine malformationis considered to cause about 15% of recurrent miscarriages. The most common abnormality is a uterine septum, a partition of the uterine cavity. The diagnosis is made by MRI or a combined laparoscopy hysteroscopy of the uterus. Also uterine leiomyomata could result in pregnancy loss.
In the second trimester a weak
cervixcan become a recurrent problem. Such cervical incompetenceleads to premature pregnancy loss resulting in miscarriages or preterm deliveries.
A balanced translocation or
Robertsonian translocationin one of the partners leads to unviable fetuses that are aborted spontaneously. This explains why a karyogramis often performed in both partners if a woman has suffered repeated abortions. About 3% of the time a chromosomal problem of one or both partners can lead to recurrent pregnancy loss. Although patients which such a chromosomal problem are more likely to miscarriage, they can also deliver normal or abnormal babies.
Aneuploidymay be a cause of a random spontaneous as well as recurrent pregnancy loss.cite journal |author= |title=Management of Early Pregnancy Loss |journal=ACOG Practice Bulletin |volume=24 |issue=February |pages= |year=2001 |publisher= American College of Obstetricians and Gynecologists] Aneuploidy is more common with advanced reproductive age reflecting decreased germ cellquality.
thyroiddisorders, both hypo- or hyperactivity, have are at increased risk for pregnancy losses. Unrecognized or poorly treated diabetes mellitusleads to increased miscarriages. Women with polycystic ovary syndromealso have higher loss rates possibly related to hyperinsulinemia or excess androgens. Inadequate production of progesteronein the luteal phase may set the stage for RPL (see below).
An important example is the increased risk of abortion in women with
thrombophilia(propensity for blood clots). The most common problem is the factor V Leidenand prothrombin G20210A mutation. Recent studies confirm that anticoagulantmedication may improve the chances of carrying pregnancy to term. It explains about 15% of recurrent miscarriages.
antiphospholipid syndromeis a generally accepted cause of recurrent pregnancy loss.
Increased uterine NK cells
A controversial area is the presence of increased
natural killer cells in the uterus. It is poorly understood whether these cells actually inhibit the formation of a placenta, and it has been noted that they might be essential for this process. A 2004 paper (Moffett "et al") warned that determination of NK cells in peripheral blood does not predict uterine NK cell numbers, because they are a different class of lymphocytes, and state that immunosuppressive treatments are not warranted.
Parental HLA sharing
Earlier studies that perhaps paternal sharing of HLA genes would be associated with increased pregnancy loss have not been confirmed.
Reduced ovarian reserve
The risk for miscarriage increases with age, and women in the advanced reproductive age who have a reduced
ovarian reserveare prone to higher risk of repeated miscarriages. Such miscarriages are due to decreased egg quality .
Luteal phase defect
The issue of a
luteal phase defectis complex. The theory behind the concept suggests that an inadequate amount of progesteroneis produced by the corpus luteumto maintain the early pregnancy. Assessment of this situation was traditionally carried out by an endometrial biopsy, however recent studies have not confirmed that such assessment is valid. Studies about the value of progesterone supplementation remain deficient, however, such supplementation is commonly carried out on an empirical basis.
While lifestyle factors have been associated with increased risk for miscarriage in general, and are usually not listed as specific causes for RPL, every effort should be made to address these issues in patients with RPL. Of specific concern are chronic exposures to toxins including smoking, alcohol, and
A number of maternal infections can lead to a single pregnancy loss, including
listeriosis, toxoplasmosis, and certain viral infections ( rubella, herpes simplex, measles, cytomegalovirus, coxsackievirus). However, there are no confirmed studies to suggest that specific infections will lead to recurrent pregnancy loss in humans. Malaria, syphilis and brucellosis can also cause recurrent abortion.
ultrasonographyhas become the primary method of assessment of the health of an early pregnancy.
In non-pregnant patients who are evaluated for RPL the following tests are usually performed. Parental chromosome testing (
karyogram) is generally recommended after 2 or 3 pregnancy losses. Blood tests for thrombophilia, ovarian function, thyroidfunction and diabetes are performed.
If the likely cause of recurrent pregnancy loss can be determined treatment is to be directed accordingly. In patients with unexplained RPL chances are about 60-70% that the next pregnancy is successful without treatment. In certain chromosomal situations, while treatment may not be available, IVF with
preimplantation genetic diagnosismay be able to identify embryos with a reduced risk of another pregnancy loss which then would be transferred. Close surveillance during pregnancy is generally recommended for pregnant patients with a history of recurrent pregnancy loss. Even with appropriate and correct treatment another pregnancy loss may occur as each pregnancy develops its own risks and problems.
* [http://www.uchospitals.edu/specialties/obgyn/pregnancy-loss/faq.html Frequently Asked Questions About Recurrent Pregnancy Loss]
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Look at other dictionaries:
Habitual abortion — The miscarriage of 3 or more consecutive pregnancies. The abortion of 3 or more miscarriages (spontaneous abortions) with no intervening pregnancies is also termed recurrent abortion. Habitual or recurrent abortion is a form of infertility. It is … Medical dictionary
habitual abortion — noun repeated spontaneous abortion (often for no known reason) • Hypernyms: ↑spontaneous abortion, ↑miscarriage, ↑stillbirth * * * noun : recurrent abortion in successive pregnancies … Useful english dictionary
Аборт Привычный (Habitual Abortion) — см. Аборт. Источник: Медицинский словарь … Медицинские термины
Abortion — In medicine, an abortion is the premature exit of the products of conception (the fetus, fetal membranes, and placenta) from the uterus. It is the loss of a pregnancy and does not refer to why that pregnancy was lost. A spontaneous abortion is… … Medical dictionary
Abortion, recurrent — The occurrence of 3 or more miscarriages (which are medically termed spontaneous abortions ) with no intervening pregnancies. Recurrent abortion (or, as it is sometimes called, habitual abortion) is a form of infertility. It may be due to… … Medical dictionary
Abortion, habitual — The miscarriage of 3 or more consecutive pregnancies. The abortion of 3 or more miscarriages (spontaneous abortions) with no intervening pregnancies is also termed recurrent abortion. Habitual or recurrent abortion is a form of infertility. It is … Medical dictionary
spontaneous abortion — noun a natural loss of the products of conception • Syn: ↑miscarriage, ↑stillbirth • Ant: ↑live birth (for: ↑stillbirth) • Derivationally related forms: ↑miscarry … Useful english dictionary
Recurrent abortion — The occurrence of 3 or more miscarriages (which are medically termed spontaneous abortions ) with no intervening pregnancies. Recurrent abortion (or, as it is sometimes called, habitual abortion) is a form of infertility. It may be due to… … Medical dictionary
АБОРТ ПРИВЫЧНЫЙ — (habitual abortion) см. Аборт … Толковый словарь по медицине
Miscarriage — Classification and external resources A complete spontaneous abortion at about six weeks from conception, i.e. eight weeks from the last menstrual period (LMP) … Wikipedia