Habitual abortion 1166093 210340836 2008-05-05T15:23:26Z Janet1983 2645165 /* Treatment */ {{DiseaseDisorder infobox | Name = Habitual abortion | ICD10 = {{ICD10|N|96||n|80}} | ICD9 = {{ICD9|629.9}} | }} '''Habitual abortion''' or '''recurrent pregnancy loss''' (RPL) is the occurrence of repeated [[pregnancy|pregnancies]] that end in [[miscarriage]] of the [[fetus]], usually before 20 weeks of gestation. RPL affects about 0.34%{{ref|RCOG2003}} of women who conceive. ==Definition== ''Habitual abortion'' (''recurrent pregnancy loss'' or ''recurrent miscarriage'') is the occurrence of 3 consecutive spontaneous miscarriages (spontaneous abortions). 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%{{ref|RCOG2003}} is regarded as "habitual". ==Causes== There are various causes for habitual abortions, and some are treatable. Some couples never have a cause identified, often after extensive investigations.{{ref|RCOG2003}} ===Anatomical conditions=== ====Uterine conditions==== An [[uterine malformation]] is 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 [[leiomyoma]]ta could result in pregnancy loss. ====Cervical conditions==== In the second trimester a weak [[cervix]] can become a recurrent problem. Such [[cervical incompetence]] leads to premature pregnancy loss resulting in miscarriages or preterm deliveries. ===Chromosomal disorders=== ====Translocations==== A [[Chromosomal translocation|balanced translocation]] or [[Robertsonian translocation]] in one of the partners leads to unviable fetuses that are aborted spontaneously. This explains why a [[karyogram]] is 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. ====Aneuploidy==== [[Aneuploidy]] may be a cause of a random spontaneous as well as recurrent pregnancy loss.{{ref|ACOG2001}} Aneuploidy is more common with advanced reproductive age reflecting decreased [[germ cell]] quality. ===Endocrine disorders=== Women with [[thyroid]] disorders, both hypo- or hyperactivity, have are at increased risk for pregnancy losses. Unrecognized or poorly treated [[diabetes mellitus]] leads to increased miscarriages. Women with [[polycystic ovary syndrome]] also have higher loss rates possibly related to hyperinsulinemia or excess androgens. Inadequate production of [[progesterone]] in the luteal phase may set the stage for RPL (see below). ===Thrombophilia=== An important example is the increased risk of abortion in women with [[thrombophilia]] (propensity for [[thrombosis|blood clots]]). The most common problem is the [[factor V Leiden]] and [[prothrombin G20210A]] [[mutation]].{{ref|ACOG2001}} Recent studies confirm that [[anticoagulant]] medication may improve the chances of carrying pregnancy to term. It explains about 15% of recurrent miscarriages. ===Immune factors=== ====Antiphospholipid syndrome==== The [[antiphospholipid syndrome]] is a generally accepted cause of recurrent pregnancy loss.{{ref|ACOG2001}} ====Increased uterine NK cells==== A controversial area is the presence of increased [[natural killer cell]]s 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 [[lymphocyte]]s, and state that [[immunosuppression|immunosuppressive]] treatments are not warranted.{{ref|ACOG2001}} ====Parental HLA sharing==== Earlier studies that perhaps paternal sharing of [[Human leukocyte antigen|HLA]] genes would be associated with increased pregnancy loss have not been confirmed. ===Ovarian factors=== ====Reduced ovarian reserve==== The risk for miscarriage increases with age, and women in the advanced reproductive age who have a reduced [[ovarian reserve]] are prone to higher risk of repeated miscarriages. Such miscarriages are due to decreased egg quality . ====Luteal phase defect==== The issue of a [[luteal phase defect]] is complex. The theory behind the concept suggests that an inadequate amount of [[progesterone]] is produced by the [[corpus luteum]] to 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.{{ref|ACOG2001}} Studies about the value of progesterone supplementation remain deficient, however, such supplementation is commonly carried out on an empirical basis. ===Lifestyle factors=== 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 [[tobacco smoking|smoking]], [[ethanol|alcohol]], and [[drugs]].{{ref|ACOG2001}} ===Infection=== A number of maternal infections can lead to a single pregnancy loss, including [[listeriosis]], [[toxoplasmosis]], and certain viral infections ([[rubella]], [[herpes simplex]], [[measles]], [[cytomegalo]] virus, [[coxsackie]] virus). However, there are no confirmed studies to suggest that specific infections will lead to recurrent pregnancy loss in humans.{{ref|ACOG2001}} ==Assessment== Transvaginal [[ultrasonography]] has 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 test]]s for [[thrombophilia]], ovarian function, [[thyroid]] function and diabetes are performed. ==Treatment== 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.{{ref|ACOG2001}} In certain chromosomal situations, while treatment may not be available, IVF with [[preimplantation genetic diagnosis]] may be able to identify embryos with a reduced risk of another pregnancy loss which then would be [[embryo transfer|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. ==References== <references/> * Christiansen OB, et al: Evidence-based investigations and treatments of recurrent pregnancy loss. Fertil Steril 2005;83:821-9. * Moffett A, Regan L, Braude P. ''Natural killer cells, miscarriage, and infertility.'' [[British Medical Journal|BMJ]] 2004;329:1283-5. PMID 15564263. * {{note|RCOG2003}} Royal College of Obstetricians and Gynaecologists - The Investigation and Treatment of Couple with Recurrent Miscarriage Guideline No 17 [http://www.rcog.org.uk/resources/Public/pdf/Recurrent_Miscarriage_No17.pdf PDF document] * {{note|ACOG2001}} [[American College of Obstetricians and Gynecologists|ACOG]] Practice Bulletin: Management of Early Pregnancy Loss. Number 24, February 2001. ==Links== * [http://www.uchospitals.edu/specialties/obgyn/pregnancy-loss/faq.html Frequently Asked Questions About Recurrent Pregnancy Loss] {{Diseases of the pelvis, genitals and breasts}} [[Category:Fertility medicine]] [[Category:Obstetrics]] [[de:habitueller Abort]] [[pt:Aborto habitual]]