Recurrent Abortion

Habitual abortion, recurrent miscarriage or recurrent pregnancy loss (RPL) is the occurrence of three or more pregnancies that end in miscarriage of the fetus, usually before 20 weeks of gestation. RPL affects about 0.34% of women who conceive.
Epidemiology
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".
Causes
There are various causes for habitual abortions, and some are treatable. Some couples never have a cause identified, often after extensive investigations.
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 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 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 experienced repeated abortions. About 3% of the time a chromosomal problem of one or both partners can lead to recurrent pregnancy loss. Although patients with such a chromosomal problem are more likely to miscarry, they may also deliver normal or abnormal babies.
Aneuploidy
Aneuploidy may be a cause of a random spontaneous as well as recurrent pregnancy loss. Aneuploidy is more common with advanced reproductive age reflecting decreased germ cell quality.
Endocrine disorders
Women with hypothyroidism 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.
Thrombophilia
An important example is the possible increased risk of abortion in women with thrombophilia (propensity for blood clots). The most common problem is the factor V Leiden and prothrombin G20210A mutation.  Some preliminary studies suggest that anticoagulant medication may improve the chances of carrying pregnancy to term but these studies need to be confirmed before they are adopted in clinical practice.  Note that many women with thrombophilia go through one or more pregnancies with no difficulties, while others may have pregnancy complications. Thrombophilia may explain up to 15% of recurrent miscarriages.
Immune factors
A common feature of immune factors in causing recurrent pregnancy loss appears to be a decreased maternal immune tolerance towards the fetus.
Antiphospholipid syndrome
The antiphospholipid syndrome is a generally accepted cause of recurrent pregnancy loss. High levels of antiphospholipid antibodies may account for 3–15% of recurrent miscarriages. In these cases, pregnancy outcomes are improved by the use of aspirin or heparin.
Thyroid antibodies
Anti-thyroid autoantibodies are associated with an increased risk of recurrent miscarriage with an odds ratio of 2.3 with a 95% confidence interval of 1.5–3.5.[5]
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.
Male-specific minor histocompatibility
Immunization of mothers against male-specific minor histocompatibility (H-Y) antigens has a pathogenic role in many cases of secondary recurrent miscarriage, that is, recurrent miscarriage in pregnancies succeeding a previous live birth. An example of this effect is that the male:female ratio of children born prior and subsequent to secondary recurrent miscarriage is 1.49 and 0.76 respectively.
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.  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 smoking, alcohol, and drugs.
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. Malaria, syphilis and brucellosis can also cause recurrent abortion.

 

When to Consult a Doctor for Surrogacy IVF

Early diagnosis will only ensure the couple has more time available for treatment before advancing age of female partner becomes an additional problem.



It is recommended that both partners are evaluated together, and finding problem in one partner should not stop the basic investigation of other.



Next step is physical examination, followed by routine infertility investigation, and finally by specific investigations and diagnostic procedures.