Allergen specific immunoglobulins during pregnancy.

In this study the serum concentration of IgE and IgG4 (total and allergen specific taking Timothy grass pollen as the model allergen) have been investigated prospectively during and after pregnancy in healthy women and women suffering from allergic rhinitis. The results show that the total serum IgG concentration remained unchanged in both groups during pregnancy. There was no significant difference in the serum concentration of IgG 4 between pregnant allergic women and non-pregnant allergic women. Levels of IgG4 were approximately twice as high (p< 0.01) in non-allergic pregnant women compared to the non-allergic nonpregnant control group. Total IgG4 concentrations were similar in allergic and non-allergic women during pregnancy; however, in the non-pregnant state allergic women had significantly (p = 0.017) higher levels of IgG4 than non-allergic women.The results show that both during pregnancy and in the non-pregnant state there was a highly significantly (p< 0.001) greater serum concentration of total IgE in allergic than non-allergic subjects. Although the level of IgE was significantly (p=0.004) lower in pregnancy, the differences are relatively small and seem unlikely to be of great physiological significance. Allergic symptomatology did not correspond to IgE levels during pregnancy. In both the pregnant and non-pregnant women the serum concentration of antigen-specific IgE was highly significantly greater in the allergic than the non-allergic subjects. However, in allergic women, the concentration of antigen-specific IgE was very much lower during pregnancy, at about 6% of the non-pregnant level (p< 0.001). The concentration of antigen-specific IgG4 was also reduced in pregnancy in allergy sufferers, being about half of the level found in the non-pregnant individuals (p< 0.001). There appeared to be an increase in spontaneous first trimester abortion in women who suffered symptoms of allergy. From the case histories of all 418 pregnancies at the Langold Health Centre ante-natal clinic attending between September 1976 and December 1990, 192 were to allergy sufferers and 226 were to normal women. The abortion rate was 16.7% in the allergic group and 5.3% in the normal pregnant women (p< 0.001).