Smoking during pregnancy increases risk of Rheumatoid Arthritis.

A study published in the International Journal of Epidemiology has implicated maternal smoking in pregnancy as a determinant of rheumatoid arthritis and other inflammatory polyarthropathies(RA&IP )during the first 7 years of life. Rheumatoid Arthritis (RA) is a chronic inflammatory disorder that leads to the destruction of cartilage and connective tissue, resulting in destruction and deformity of the joints. Several studies have shown that maternal smoking in pregnancy can cause a whole series of adverse reactions on the baby.

The present study included nearly 59000 children born in the year 1987. The births were identified from the Finnish Medical Birth Registry. The children were then followed up for seven years. From the birth registry information was collected about the smoking of the mother during pregnancy. The amount of cigarette smoking in the pregnant mothers was classified as no smoking, low exposure which included those who smoked less than 10 cigarettes a day and high exposure which included those who smoked more than 10 cigarettes a day.

In all 75 cases of rheumatoid arthritis and other inflammatory polyarthropathies were identified. Less than half of them were classified as juvenile rheumatoid arthritis. High exposure to tobacco smoke increased the risks of RA&IP and juvenile rheumatoid arthritis in girls. . If the mother smoked more than ten cigarettes per day during pregnancy, the risk of chronic joint sickness increased significantly for girls.

But this coherence seems to apply only to girls and was not found in boys. The reasons for this gender difference are unclear. This is one more study stressing the ill effects of smoking and in particular smoking during pregnancy.