Recurrent Miscarriage

Recurrent Miscarriage & Recurrent Pregnancy Loss

Recurrent miscarriage, also known as recurrent pregnancy loss (RPL), is defined as two or more consecutive miscarriages. A miscarriage is defined as the spontaneous loss of a clinically-recognized pregnancy before the 20th week, meaning the fetus has been identified with ultrasound or through tissue after the pregnancy loss.

At the Reproductive Science Center of New Jersey (RSCNJ), we’re committed to getting to the root cause of recurrent miscarriage and pregnancy loss and providing our patients with personalized treatment plans to increase their chances of pregnancy success. If you’ve experienced RPL, you aren’t alone, and we’re here to support you through each step of your fertility journey.

Recurrent Miscarriage & Recurrent Pregnancy Loss at a Glance

• While normal miscarriages happen in about 25% of pregnancies, recurrent miscarriage occurs in about 2% of pregnancies.
• According to the American Society for Reproductive Medicine, the most common causes of recurrent miscarriage are the age of the mother and genetic defects
• Treatment for recurrent miscarriage may involve medications, surgery, or the use of in vitro fertilization (IVF) to achieve pregnancy.
• About two-thirds of women who have suffered recurrent miscarriage have a successful pregnancy in subsequent efforts.

Understanding Recurrent Miscarriage

The U.S. Department of Health and Human Services estimates that less than 5% of pregnant women experience two consecutive miscarriages. About 1% experience three or more consecutive miscarriages. After three or more consecutive losses, there is a 40% chance for a fourth loss.

Before week 20, women may have a chemical pregnancy, when hormone levels indicating pregnancy are present but an ultrasound does not confirm the fetus. This may mean it is an ectopic pregnancy, in which the embryo implants outside the uterus, and the pregnancy must be ended.

About two-thirds of women who have suffered recurrent pregnancy loss have a successful pregnancy in subsequent efforts. A healthy lifestyle can help improve those odds: getting moderate exercise, controlling weight, quitting smoking, and reducing alcohol and caffeine intake may be beneficial in avoiding RPL.

Even though the percentage rate is in favor of a successful pregnancy after recurrent miscarriage, the psychological impact on the woman and couple can be significant. Therefore, we conduct a recurrent pregnancy loss evaluation after two losses to help avoid a third if possible.

Symptoms of recurrent miscarriage

Symptoms for recurrent miscarriage are not more severe than those for a single miscarriage. If a woman experiences any of the following symptoms while pregnant, she should seek medical attention immediately:

• Vaginal bleeding
• Passing of fetal tissue
• Cramping and pain in the abdomen
• Fever

Causes of recurrent miscarriage

Pinpointing the cause of repeated miscarriages can be difficult. In more than half of couples with recurrent pregnancy losses, doctors are unable to find a specific reason. However, there are a number of factors at play, including:

Age

Age increases the chance of a miscarriage. Age-related pregnancy loss is associated with poor egg quality, which leads to genetic abnormalities. More than one-third of all pregnancies after age 40 end in miscarriage.

The best available technique for assessing the quality of a woman’s eggs is measuring what’s known as ovarian reserve, determined by levels of follicle stimulating hormone (FSH) and estradiol. In some cases, a clomiphene challenge test is performed in women over the age of 38 who have a solitary ovary or have had a prior poor response with fertility medications. These tests can help us determine the chances of pregnancy success using a woman’s own eggs.

Genetic factors

Recurrent pregnancy loss due to chromosomal abnormalities affects approximately 3-8% of all pregnancies. For both natural and assisted conception, chromosomally abnormal embryos have a low rate of implantation in the uterus. The most common genetic cause of RPL is aneuploidy, the presence of an extra chromosome or the absence of one in the normal pair of chromosomes. Down syndrome, also known as trisomy 21, is the presence of an additional 21st chromosome and is a common form of aneuploidy. Chromosomes also play a factor in such cases of advanced maternal age, as most embryos that end in miscarriage for these women carry an abnormal number of chromosomes.

Environmental factors

Environmental exposures could affect the outcome of a pregnancy. Some anesthetic agents and tetrachloroethylene used in dry cleaning have been associated with miscarriages. If proper precautions are used, including a mask respirator and specialized clothing, then the exposure is minimal and should not cause a problem.

Additionally, several reports have shown a strong association between smoking and pregnancy losses. The risk increases with the number of cigarettes smoked per day. Exposure to aspartame (an artificial sweetener found in a variety of beverages and used as a sugar substitute in brand-name products such as Equal and NutraSweet), heavy caffeine, and alcohol intake have all been associated with pregnancy loss, but scientists have not defined the exact amount. Therefore, we recommend limiting the intake of these substances while trying to conceive and avoiding them during pregnancy.

Endocrine problems

An endocrine problem is found in 15 percent of women who have RPL. Any hormonal imbalance tthat affects ovulation could impair normal uterine lining development and ultimately, implantation. Thyroid disease or pituitary dysfunctions are the most common findings associated with RPL due to endocrine issues. Women with an elevated luteinizing hormone (LH) level, as with polycystic ovary syndrome (PCOS), may be at increased risk of miscarriage due to an increased amount of male hormones that adversely affect the uterine lining.

Anatomical causes

Uterine anomalies are found in 12-15% of women with pregnancy losses and also contribute to RPL. These abnormalities include fibroid tumors, derived from the muscle wall of the uterus, or polyps, overgrowths of the uterine lining.

Congenital uterine malformations, such as a uterine septum, are associated with a 60% pregnancy loss rate. Surgical correction by operative hysteroscopy has been reported to provide an 80% delivery rate.

Incompetent cervix is a condition in which the cervix opens prior to 20 weeks of gestation without detectable contractions. In these women, the use of cervical cerclage, a suture placed in the cervix, at the end of the first trimester, may reduce the risk of a pregnancy loss.

Uterine anomaly percent risk for a pregnancy loss is as follows:

• Septate – 60 percent
• Unicornuate – 35 percent
• Bicornuate – 33 percent
• Didelphic – 29 percent
• DES exposure – 28 percent

Blood clotting abnormalities

Abnormalities in blood clotting function resulting from chromosomal anomalies are also a potential cause of pregnancy losses and RPL.

Thrombophilia is the tendency for increased blood clotting and may be treated with baby aspirin, heparin anticoagulant injections, or an increased amount of folic acid.

Antiphospholipid syndrome (APS or APLS) may cause 3-15% of RPL in women. APS is also a coagulation disorder that causes thrombosis in both arteries and veins and can lead to miscarriages, pre-term delivery, or severe preeclampsia, a serious threat to both maternal and infant health.

Immunologic factors

Blood clots in the small placental blood vessels may be due to the antibodies lupus anticoagulant and anticardiolipin that attach to the wall of the blood vessel and attract clotting factors that can impede blood flow, resulting in placental insufficiency and possible miscarriage. Treatment with aspirin or heparin anticoagulant injections does not guarantee improvement, but studies have reported success rates around 85% for most women.