Recurrent pregnancy loss (RPL) is defined as the miscarriage of three or more pregnancies prior to 20 weeks of gestation. The risk of a single miscarriage ranges from 15% to 50% or more per pregnancy, depending on the woman’s age. In contrast, approximately 1% of couples suffer from RPL. RPL is an emotionally challenging experience.
At the Family Fertility Center, we offer you an evidence-based approach toward understanding miscarriage as well as towards preventing future miscarriages. In addition, we offer on-going close monitoring of all subsequent pregnancies to provide support during a generally anxiety-provoking time. We recognize the emotional toll that miscarriage can take on a couple and referral to psychologists and counselors in our community is available to provide additional emotional support to all couples with RPL. After a thorough fertility evaluation, 50% of couples with RPL will have a cause identified. Potential diagnostic testing includes the following:
Luteal Phase Defect
The classic definition of luteal phase defect requires two endometrial biopsies in two consecutive cycles. Recently there is dispute among experts on the reliability and methodology of endometrial dating. There is, however, general agreement that insufficient progesterone after ovulation, and to a much lesser extent estrogen level as well, can lead to either failure to implant successfully or early miscarriage. Treatment of luteal phase defect is primarily supplementation of progesterone which can be given by different routes of administration: oral, vaginal or intramuscular. In the alternative, luteal phase defect can be corrected through correction of minor ovulatory dysfunction with ovulation induction agents such as clomiphene citrate or gonadotropin injections.
Parental Chromosome Testing
In up to 4% of couples who experience RPL, one or both partners will have an abnormality of chromosome structure. In such cases, one possible therapy is in vitro fertilization (IVF) with biopsy and chromosomal evaluation of each embryo, called pre-implantation genetic diagnosis (PGD).
Abnormalities of the uterine cavity account for approximately 15% of cases of RPL. Abnormalities may include a uterine septum (an abnormally-shaped cavity), intra-uterine scar tissue, polyps or fibroids. Diagnostic tests such as hysterosalpingograms (HSG), saline sonohysterograms, and hysteroscopy can be used to evaluate the uterine cavity. Many abnormalities within the uterine cavity can be corrected with minimally invasive surgical interventions.
In approximately 15% of couples with RPL, the cause may be related to circulating antibodies that interfere with the proper functioning of the tissue that supports the pregnancy (the placenta). Blood tests are performed to identify a set of these antibodies and, if found, the diagnosis of anti-phospholipid antibody syndrome (APS) can be made. APS has been shown to respond to treatment with blood thinning medications.
Blood Clotting Disorders (Thrombophilias)
Some women with RPL have been shown to have inherited disorders that cause clots in the blood vessels to occur more easily than in other women. The link between thrombophilas and miscarriage is strongest for women experiencing losses in the second and third trimesters. Evidence regarding the benefits of blood thinning medications to prevent miscarriage is currently lacking, though studies in this area are on-going.
Women with uncontrolled diabetes mellitus and uncorrected thyroid-gland dysfunction are at an elevated risk of miscarriage. Correction of hormonal imbalances is recommended in these cases.
Fetal Chromosomal Anomalies
As many as 70% of all miscarriages are due to chromosomal abnormalities in the fetus. Although this problem arises in increasing frequency as women age, it is a phenomenon that occurs across all age groups. This type of miscarriage is often referred to as “random miscarriage.”
Unproven Tests and Treatments
The search for a solution for RPL has led to the use of several tests and therapies not proven to be useful. These include:
- Maternal antibodies directed against paternal cells
- Chemicals toxic to embryo development (embryotoxic factors)
- Intravenous immunoglobulin (IVIG)
- White blood cell (leukocyte) immunization
As many as 50% of women with RPL will have no specific cause identified despite a diligent evaluation. Many couples find it quite frustrating to have no clearly identified cause for their losses. Many studies, however, have shown that with continued attempts at conception and no additional interventions, the prognosis for a future live birth remains quite good for couples with unexplained recurrent pregnancy loss. Depending on age, chances for a live-birth in subsequent pregnancies for these couples range from 50%-80%.