A new study suggests that the age at which a woman has her first baby may be linked to her risk of developing rheumatoid arthritis later in life.
Researchers found that women who had their first child before the age of 26 or after the age of 35 were more likely to develop the disease than women who became mothers between the ages of 30 and 32. The findings were published in the journal PLOS ONE.
Rheumatoid arthritis is a long-term autoimmune disease. In an autoimmune disease, the body’s immune system mistakenly attacks healthy tissues instead of protecting them from infections. In rheumatoid arthritis, this attack mainly affects the joints, causing pain, swelling, stiffness, and warmth.
Over time, the disease can damage joints and make everyday activities such as walking, dressing, or holding objects much more difficult. Some people also develop tiredness, fever, and inflammation in other parts of the body.
Although scientists know that genes, smoking, hormones, and environmental factors all play a role in rheumatoid arthritis, the exact cause is still not fully understood. Researchers have also become interested in whether pregnancy and childbirth may influence a woman’s future risk because pregnancy causes major changes in hormone levels and the immune system.
To explore this question, researchers from the First Teaching Hospital of Tianjin University of Traditional Chinese Medicine in China analyzed information collected through the U.S. National Health and Nutrition Examination Survey. Their study included 7,449 women whose health information was gathered between 2011 and 2020.
The scientists focused on each woman’s age at first birth, often called AFB, and compared it with whether she later developed rheumatoid arthritis. After analyzing the data, they found that the relationship was not a straight line. Instead, the lowest risk appeared among women who had their first child between the ages of 30 and 32.
Compared with this group, women who had their first baby before the age of 18 had about four times the risk of rheumatoid arthritis. Women who first gave birth between 18 and 20 years of age had about 2.9 times the risk. Those aged 21 to 23 had about three times the risk, while women aged 24 to 26 had about 3.18 times the risk.
Women who had their first child after the age of 35 also had a higher risk, about 3.36 times greater than the reference group. However, women who had their first baby between the ages of 27 and 29 or between 33 and 35 did not show a meaningful increase in risk.
The researchers do not know exactly why these differences exist. One possible explanation is that pregnancy affects hormone levels and immune function differently at different ages.
The body’s inflammatory response may also change over time. It is also possible that lifestyle, overall health, genetics, or other factors contribute to the relationship. Because this was an observational study, it cannot prove that the age of first childbirth directly causes rheumatoid arthritis.
The findings do not mean that women should choose when to have children based on arthritis risk alone. Decisions about pregnancy depend on many personal, medical, family, and social factors. Instead, the study helps scientists better understand which groups of women may benefit from closer monitoring for early signs of joint disease.
Early diagnosis of rheumatoid arthritis is important because treatment works best before severe joint damage develops. People should speak with their doctor if they notice ongoing joint pain, swelling, stiffness that lasts for weeks, or morning stiffness that improves slowly during the day.
Maintaining a healthy lifestyle may also support overall joint health. Regular physical activity, not smoking, eating a balanced diet, maintaining a healthy weight, and following medical advice can all help reduce the risk of many chronic diseases.
Some research has also explored whether nutrients such as vitamin K, krill oil, and foods like yogurt may support bone or muscle health, although more studies are needed to confirm their effects.
The researchers believe larger studies will help explain why the age at first birth appears to influence rheumatoid arthritis risk. Understanding these biological changes could eventually lead to better prevention strategies and earlier treatment for women who may face a higher risk later in life.
If you care about arthritis, please read studies about extra virgin olive oil for arthritis, and pomegranate: A natural treatment for rheumatoid arthritis.
For more information about arthritis, please see recent studies about how to live pain-free with arthritis, and results showing medical cannabis may help reduce arthritis pain, back pain.
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