Methotrexate is a first-line treatment for rheumatoid arthritis. If a person takes this drug during pregnancy, it can cause birth abnormalities. Both partners should avoid methotrexate when planning to become pregnant and during pregnancy.

Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes inflammation of the joints. It is 2–3 times more common in females than in males.

Methotrexate can help people manage their RA symptoms. However, it can also cause severe toxicity.

In this article, we provide important information on how methotrexate affects women during pregnancy.

Sex and gender exist on spectrums. For the purposes of this article, we use “male” and “female” to refer to a person’s sex assigned at birth. Learn more.

Methotrexate medication for rheumatoid arthritis during pregnancy.Share on Pinterest
Taking methotrexate for rheumatoid arthritis can cause birth abnormalities.

Methotrexate minimizes the body’s immune response and reduces folic acid in the body. Folic acid plays an essential role in how a fetus develops in the womb.

The Food and Drug Administration (FDA) does not approve the use of methotrexate during pregnancy. They state that people should avoid pregnancy if either partner is taking the drug. People should also avoid methotrexate when nursing.

Taking methotrexate in pregnancy may lead to birth abnormalities that affect a child’s physical and mental development. In some cases, methotrexate can result in fetal death.

Examples of birth abnormalities that methotrexate may cause include:

  • neural tube defects that affect the brain, spine, or spinal cord, including spina bifida and encephalocele (a protrusion at the base of the skull)
  • a cleft palate
  • a condition called cleidocranial dysostosis, which causes abnormalities in the teeth and collarbones
  • hypertelorism, which is a greater distance than normal between two body parts, often the eyes

Methotrexate can affect the fetus if either parent has been taking it. Males should not take methotrexate when trying for a baby.

People can avoid unplanned pregnancies by using an effective form of birth control. These include condoms, the birth control pill, and intrauterine devices (IUDs).

According to the FDA, males should stop taking methotrexate at least 3 months before getting a partner pregnant. Females should wait for at least one cycle of ovulation before trying to become pregnant.

According to 2020 guidelines released by the American College of Rheumatology (ACR), people with RA should consider prepregnancy counseling to encourage conception while RA symptoms are dormant. They should also continually speak with their obstetrics/gynecology doctors for all reproductive health issues.

Doctors may use methotrexate injections to treat an ectopic pregnancy because they interrupt the growth and division of a fertilized egg.

Specifically, methotrexate interrupts the supply of a hormone called human chorionic gonadotropin (hCG) to the fertilized egg. Without hCG, the egg cannot grow.

An ectopic pregnancy occurs when a fertilized egg implants outside of the womb. This serious condition can lead to complications, such as internal bleeding, infertility, and, in some cases, death.

Symptoms of an ectopic pregnancy include:

  • vaginal bleeding or spotting
  • cramping or abdominal pain
  • nausea
  • skin sensitivity

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A woman taking methotrexate can speak with a doctor about alternative medication for RA.

If someone who can become pregnant is taking methotrexate and suspects that they are pregnant, they should take a pregnancy test as soon as possible. If the test is positive, they should stop taking methotrexate and see a doctor as soon as possible.

A doctor can offer advice about alternative RA medications to take during pregnancy.

The authors of a 2016 article suggested the following drugs as suitable alternatives to methotrexate during pregnancy or when trying to conceive:

  • azathioprine
  • hydroxychloroquine
  • sulfasalazine
  • corticosteroids at low doses

People can also take over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) during the first two trimesters to help manage RA symptoms. However, a person should consult their doctor before taking any medication while pregnant.

All medication has the potential to cause side effects. People can discuss their options with a trained healthcare professional.

Methotrexate, a common treatment for RA, can cause birth abnormalities if either partner takes the drug during conception or pregnancy.

People who become pregnant while taking methotrexate should stop taking methotrexate and contact a doctor as soon as possible. Partners should stop taking methotrexate at least 3 months before getting pregnant.

People using methotrexate who are planning on becoming pregnant should speak with their doctor first. A doctor can advise people on their best alternatives for treating RA during pregnancy.