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CHORI Study Confirms that Rheumatoid Arthritis May Cause A Delay in Time to Pregnancy

A new study by CHORI scientist Damini Jawaheer, PhD,and her colleagues, showing that women who have rheumatoid arthritis (RA) may take longer to conceive than women without RA, has been causing a stir as it confirms the findings from the only previous study conducted on this topic.

"Until the results from such a study are replicated, you can't really confirm that the findings are accurate. Our study, which indicated a slight association between rheumatoid arthritis and a delayed timed to pregnancy, actually confirms the earlier findings," explains Dr. Jawaheer of the study that Reuters picked up the day the results were made public.

"In addition, we used a national registry system in order to gather a significant amount of data, which provides a model for future research in this field."

“Our study, which indicated a slight association between rheumatoid arthritis and a delayed timed to pregnancy, actually confirms the earlier findings.”

RA is a chronic inflammatory disease that results in the joints in the body being attacked by one's own immune system. It is a significant problem throughout the world, affecting approximately one percent of the adult world population. In the United States alone, at least 1.5 million individuals suffer from the disease.

"RA is one of the worst forms of arthritis and one of the leading causes of chronic impairment worldwide," says Dr. Jawaheer. "The symptoms can range from mild inflammation to severe, crippling arthritis in which the joints are destroyed."

While RA can have a significant impact on quality of life, very few studies have been conducted on how RA might impact the ability to conceive. As Dr. Jawaheer explains, there are a number of reasons for this.

"The reason there are so few studies on this topic there is only one previous study that examined the effect on RA on time to pregnancy is that RA tends to have a late onset. It usually happens in the mid-forties, especially among women, and the incidence goes up with age from there," says Dr. Jawaheer.

Because of the late-onset, finding enough women to participate in such a study who both have RA and are pregnant becomes problematic.

"In the United States, for example, finding enough participants for a study to have meaningful statistical results would be very difficult," says Dr. Jawaheer.

As a result, Dr. Jawaheer partnered with Jorn Olsen, MD, PhD, the Chair of Epidemiology at the University of California, Los Angeles (UCLA), who also has an affiliation with the University of Aarhus, in Denmark.

"By working with Dr. Olsen, who established the Danish National Birth Cohort (DNBC), we were able to also access data from the Danish National Hospital Discharge Registry," says Dr. Jawaheer. "National registries such as these are an invaluable resource because they allow you to look at very large datasets."

The results of the study indicated that the time it takes for women to get pregnant (time to pregnancy) is slightly longer for women with RA than for women without RA.
“When we compared women who already had RA before the pregnancy with women who did not have RA,  those with RA were more likely to take longer to conceive.”
"What this shows is that something associated with the disease or perhaps the disease itself causes a longer time to pregnancy. In general, however, women with RA are able to conceive, even if it takes a little longer," says Dr. Jawaheer.

While questions still remain as to why women with RA may take longer to conceive, Dr. Jawaheer's study confirms the results from the only other existing study to examine similar questions, and provides a model of using national health registries to study time to pregnancy and RA in women.


Friday, June 10, 2011 9:55 AM

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