Recurrent Miscarriage

Recurrent pregnancy loss is defined as having two or more unsuccessful pregnancies. Roughly 25 percent of all pregnancies result in a miscarriage, but only five percent of women will experience two consecutive miscarriages and one percent of women will experience tree or more losses.  After three or more miscarriage, your physician will probably recommend a thorough evaluation to try and determine a causative factor.

Many different causes can exist for why a woman to is experiencing recurrent loss.  Your doctor will evaluate the possible genetic and chromosomal causes by drawing blood to determine if you and your partner are carriers of an inherited genetic abnormality.  Only about five percent of all couples who are tested have genetic issues.  

The most common genetic abnormality is translocation, which happens when an embryo receives too much or too little genetic information because one part of the chromosome is attached to another chromosome.  Many times, this condition is unknown to a couple because the partner carries the translocation is normal.  Couples who have a known genetic disorder should consider doing in-vitro fertilization (IVF) with preimplantation genetic screening (PGS) so that your doctor and the embryologist can select healthy embryos for transfer.

Most early miscarriages are due to random chromosomal abnormalities in the embryo. These abnormalities, include a missing or duplicate chromosome, occur in approximately 60 percent of reported early miscarriages.

A woman’s age can also play an important role in the occurrence of miscarriage.  After age 40, 33 percent of all pregnancies result in miscarriage, probably due to chromosomal abnormalities in the egg as a woman ages.  Many women choose to use donor eggs as it optimizes their chances of delivering a healthy baby and minimizes the chance chromosomally abnormalities in the pregnancy.

Hormones also play an important role in a successful pregnancy. Progesterone is a hormone that helps to support and maintain a pregnancy.  Low levels of progesterone, called a luteal phase defect, may contribute to recurrent pregnancy loss.  Treatment with progesterone supplementation may improve the chances of a successful pregnancy outcome, although no conclusive evidence exists to support this theory.

Poorly controlled diabetes can also have a negative affect on pregnancy and can contribute to recurrent loss. Obese patients and those who have PCOS are also at a higher risk for recurrent loss due to insulin resistance.  Controlling blood sugar levels, even before pregnancy, is important because it optimizes the chances for a successful outcome.

Uterine abnormalities account for 10 to 15 percent of recurrent pregnancy losses. Certain uterine issues are present from birth, such as a uterine septum, unicornuate uterus, and a double uterus; these conditions can cause recurrent loss because the endometrium is unable to adequately nourish the pregnancy due to a compromised blood supply. Uterine fibroids and polyps can develop over time and may result in recurrent pregnancy loss depending on their location.  Your doctor can identify any of these issues by performing a hysterosalpingogram (HSG) or saline infused sonogram (SIS). Some uterine abnormalities may be repaired through surgical intervention, which can improve the pregnancy outcomes.

About 3 to 15 percent of recurrent pregnancy losses occur because of antiphospholipid syndrome, a condition in which blood clots can develop and compromise blood flow to the fetus.  Blood tests for anticardiolipin antibodies and lupus anticoagulant can identify if antiphospholipid syndrome is present and may be a contributing factor to recurrent pregnancy loss. Treatment with blood thinners such as aspirin and heparin has shown improved pregnancy outcomes.

In 50 to 75 percent of couples, no explanation is found to explain why the recurrent pregnancy losses have occurred, but 60 to 70 percent of couples go on to have a successful outcome. When you start trying to conceive after a loss, take time to make sure that you take good care of yourself and that you are physically and emotionally ready.