(information provided by William P. Bunnell, M.D, Alfred I duPont Institue, Wilmington Delaware)

Because progressive scoliosis is so much more common in women than in men, doctors at the Alfred I duPont Institute in Wilmington, Delaware studied 355 female patients to determine the effect of pregnancy on curve progression. The doctors also decided to see if there was an increased risk to the child born to a woman with scoliosis.

Each woman in the study had idiopathic scoliosis, was first seen at the Institute prior to 1975, and had an x-ray taken at the time of skeletal maturity. Each woman was asked to fill out a detailed questionnaire and submit to a current x-ray examination. Of the 355 women,178 had never been pregnant and 177 had at least one pregnancy. Both of these groups included patients who were treated either with observation, bracing, or surgery.

With women who were treated by observation, the risk of curve progression was essentially the same for pregnant and nonpregnant groups. In this group, curves increased more than 10 degrees in 9% of the pregnant women and 11 % of the nonpregnant women.

With women who were treated by bracing, there was a greater difference between the two groups. In this group, curves increased more than 10 degrees in 11 % of the pregnant and only 2% of the nonpregnant women.
However, at 11 %, the pregnant group compares exactly with the whole observation group, while at 2%, the nonpregnant patients showed nearly a 50% reduction in risk of curve progression. This difference is statistically significant, but the explanation remains unknown.

With women who were treated by surgery, there was almost no curve progression in either the pregnant or nonpregnant group. Only 2 women out of the 65 in the pregnant group had curve progression of under 10 degrees, in the unfused segment. None of the nonpregnant group had progression in the unfused segment.

The severity of the curvature at the last visit prior to pregnancy was analyzed next. The risk of curve progression is nearly identical in both the pregnant and nonpregnant group. However, as the degree of curvature increases, there is a slight increase in the risk of curve progression for both the pregnant and nonpregnant group.

In analyzing the curve pattern, the researchers discovered that the risk of curve progression of more than 10% is slightly higher for thoracic and double major curves for both groups.

The study was positive in that no significant problems occured during pregnancy that could be specifically attributed to scoliosis. Of the 176 patients who delivered 251 full-term children, a cae- sarean section was necessary in only 7.6%. The national average for caesarean sections is 16%. Only 5.1% of the children had congenital problems; this again is below the national average of 7%.

In conclusion, pregnancy does not increase the risk of curve progression after skeletal maturity. The risk of curve progression during pregnancy is unaffected by the age at first pregnancy, the number of pregnancies, and by the stability of the curve at skeletal maturity. In addition, the pregnancy itself is rarely affected by scoliosis.