Recurrent Miscarriage (Pregnancy Loss)

What are Recurrent Miscarriages?

Miscarriages are fairly common, occurring in about 10% of clinically recognized pregnancies.¹ However, the likelihood of recurrent miscarriage is small, occurring only in about 1% of pregnancies according to the American College of Obstetricians and Gynecologists (ACOG).¹ Recurrent pregnancy loss often indicates a fertility issue or another medical condition.

Most miscarriages occur within the first trimester (first 12 weeks of pregnancy). Loss of pregnancy occurring during the second and third trimesters are far less common and are generally not classified as miscarriages. Instead, a pregnancy loss experienced outside the first trimester is called a stillbirth.

Causes of Recurrent Miscarriage

When searching for what causes miscarriage, the first very important answer is that it was likely nothing anyone could have prevented.

Most miscarriages are completely out of the woman’s or couple’s control and are largely caused by random genetic defects preventing a specific fetus from coming to term. These are some common causes that can lead to a miscarriage.

Genetics

According to ACOG, about 60% of miscarriages are due to an abnormal number of chromosomes the embryo receives during fertilization, either from the sperm, the egg or both.¹ Put simply, the embryo is not genetically viable (able to grow). These chromosome issues occur by chance and randomly, and are not generally influenced by anything a woman or couple did or did not do.

In some cases of recurrent miscarriage, the cause is due to a chromosome defect called a translocation. This is when one of the parents has a piece of one chromosome misplaced in another chromosome.

Structural Abnormalities in the Uterus or Cervix

Approximately 10% to 15% of women with a history of recurrent miscarriage have an abnormally shaped uterus. A septate uterus, which involves tissue protruding into the inner cavity of the uterus, causes miscarriage due to inadequate blood supply to the fetus.

Second trimester miscarriages may also occur due to a weakened cervix. After trauma or surgery, cervix muscles may not be able to hold the growing fetus. Uterine fibroids and polyps also can affect the womb’s ability to retain a pregnancy.

In these cases, it’s important to work with our fertility specialists to find treatments that could help.

Hormonal Issues

Hormones play a big part in ovulation and reproduction, so any imbalance can lead to an increased risk for miscarriage. For example, some women may suffer from low levels of progesterone, which can prevent the embryo from implanting in the uterus. After the age of 30, most men will experience a drop in testosterone that can lead to decrease in sperm production and quality.

Infections or illness

Pregnancy loss and its relationship to the immune system is under investigation. In rare cases, an infection or illness could contribute to a miscarriage risk. These may include:

• A sexually-transmitted infection, such as chlamydia or gonorrhea.
• AIDS and HIV.
• Food poisoning during pregnancy.

Ectopic Pregnancy

An ectopic pregnancy occurs when a pregnancy develops outside the womb, typically in a fallopian tube. An ectopic pregnancy may result in miscarriage naturally. However, ectopic pregnancy is very dangerous to a woman’s health and an ectopic embryo cannot survive because it lacks space to grow, so if it does not miscarry naturally, a medical provider must intervene for the patient’s safety.

Risk Factors for Miscarriages

Several conditions and lifestyle factors can increase one’s risk of miscarriage.

Age of Both Partners

One of the biggest factors in miscarriage risk is maternal and paternal age. This is because as we age, the risks for chromosomal abnormalities increase. In general, a woman who is 35 years old has an increased risk of a miscarriage compared with a woman under the age of 35. Chances increase more as individuals enter their 40s.

Smoking, Alcohol and Drug Use

Smoking, drinking alcohol and drug use can increase the risk of miscarriage. Women should always consult their physician before taking any medicine during pregnancy, and they should also alert doctors and dentists before receiving X-rays or prescriptions for medicine.

Underlying Health Conditions

Some maternal health conditions can lead to an increased risk for miscarriage, either due to the condition itself or related symptoms. These conditions include:

• Poorly controlled diabetes
• Heart disease and high blood pressure
• Polycystic ovary syndrome (PCOS)
• Thyroid disease
• Autoimmune disorders, like lupus
• Exposure to harmful chemicals or radiation
• Physical trauma
• Obesity or being underweight

Treatment Options

Treatment depends on the cause of a particular woman’s miscarriages. It can range from lifestyle changes and medication to surgery and assisted reproductive technologies to increase the chance of a successful pregnancy. With certain conditions surrounding recurrent miscarriage, medical or surgical treatments can lower a woman’s risk for future miscarriage.

The most common treatments include:

• Medications to correct hormonal imbalances
• Genetic testing of both partners to identify possible problems
• Surgery to remove uterine fibroids, or to correct uterine structure
• In vitro fertilization (IVF) with preimplantation genetic testing to identify embryos that have a genetic problem
• Use of blood thinners when pregnant, in women with clotting disorders
• Weight management and making other healthy lifestyle choices

If you’re experiencing recurrent miscarriages on your conception journey, you still have a good chance of becoming pregnant. With a diagnosis, we can usually correct the issue or work around it with fertility treatments. Schedule a miscarriage consult at The Fertility Institute to begin today.