Recurrent pregnancy loss is defined as the loss (miscarriage) of three or more consecutive pregnancies. Almost 20 percent of all pregnancies (one in five) end in miscarriage. The risk of miscarriage is 9.5 percent for women younger than age 24. This risk rises steadily with age, increasing to 11 percent by age 30 and reaching 33 percent in women age 40. For women over age 44, the incidence of miscarriage increases dramatically to 53 percent. The IHR repeated pregnancy loss experts work closely with couples undergoing the many different types of assisted fertility treatments available. We are renowned for our specialized knowledge and high infertility success rates even in difficult cases. IHR's expertise in repeated pregnancy loss lies in our willingness and ability to individualize our approach to best suit each and every one of our patients.
Pregnancy loss can take a significant emotional toll. However, 60 percent of all women who are diagnosed with unexplained recurrent pregnancy loss achieve a successful pregnancy with minimal treatment. The rate of success improves to over 75 percent for women who suffer recurrent loss as the result of an identifiable cause and undergo appropriate treatment.
Our laboratory workup is designed to identify possible causes for a woman's recurrent pregnancy loss. These factors include: anatomical factors, genetic factors, infection, immune factors, endocrine factors, and unexplained factors.
Anatomical factors: Uterine abnormalities are a possible cause of recurrent pregnancy loss. A saline-ultrasound or an x-ray dye examination can be performed to evaluate the uterus. Surgery to correct uterine abnormalities is an effective and low-risk outpatient procedure.
Genetic factors: Approximately 70 percent of early spontaneous miscarriages are associated with fetal chromosomal abnormalities. In addition, 30 percent of second trimester miscarriages and 3 percent of stillbirths have abnormal chromosomes. In most cases, the couple is chromosomally normal and the fetal chromosomal abnormality is a random event. Preimplantation genetic diagnosis (PGD), can be performed in conjunction with IVF and allows genetic testing to be done on embryos prior to transfer. PGD can benefit women with a history of repeated miscarriages, those at risk for having a child with an inherited genetic disorder (e.g., cystic fibrosis, muscular distrophy), or those who have failed to achieve pregnancy after multiple attempts with IVF.
Infection: Any severe maternal infection that leads to bacteria (or viremia) can cause sporadic miscarriage. However, the role of infection in the cause of recurrent miscarriage is unclear.
Immune factors: There is a well-established association between recurrent miscarriage and antiphospholipid antibodies (aPL) — a class of proteins that in some cases appear to attack an early developing pregnancy. The live birth rate may be as low as 10 percenet in women with recurrent miscarriages attributed to aPL. The live birth rate significantly improves to 70 percent when aPL is treated with low dose aspirin together with low dose heparin.
Endocrine factors: Systemic maternal endocrine disorders such as diabetes mellitus and thyroid disease have been associated with miscarriage. But well-controlled diabetes is not a risk factor for recurrent miscarriage, nor is treated thyroid dysfunction. Inadequate secretion of progesterone during the menstrual cycle and in the early weeks of pregnancy is considered a possible factor in many cases of recurrent miscarriage. Another possible endocrine factor is the prevalence of polycystic ovaries (PCO), a condition of the ovaries where there are many medium-sized follicles around the rim of the ovaries, often seen with the ovulation disorder polycystic ovary syndrome (PCOS).
Unexplained factors: For a number of women, the recurrent episodes of pregnancy loss will remain unexplained despite careful investigation. It is important for these women to know that the prognosis for future pregnancy with counseling alone is approximately 75 percent.