Background and purpose: Sulfur is an essential element used in the amino acids cysteine and methionine. Sulfur toxicity occurs due to its high concentration and volatile compounds in the environment. In various stages of human life, sulfur contaminants cause a variety of disorders in different parts of the body including the immune system. The embryonic period is the most critical stage of life cycle, so, this study investigated the effects of sulfur intoxication in pregnant rats on serum levels of immunoglobulin in their neonates.

Materials and methods: In this experimental study, 36 adult female Wistar rats were divided into three groups: a control, experimental group I with mild poisoning and experimental group II with severe intoxication. Before and during pregnancy the experimental groups I and II received a daily dose of 500mg/kg.bw sodium sulfide dissolved in drinking water for 15 and 30 days, respectively. Blood samples were taken from male and female newborns, 40 days after birth, and the serum levels of IgG and IgM were measured using nephelometric technique. Data was analyzed in SPSS ver. 17.

Results: The results indicated a significant increase in serum levels of immunoglobulin IgG and IgM in male and female neonates with severe maternal toxicity compared to the control group (P < 0.05). On the other hand, there was no significant difference in the concentration of immunoglobulins in female newborns of all groups compared to the corresponding male group. (P>0.05)

Conclusion: Sulfur contaminants or their metabolites can cross the placental barrier during pregnancy and increase serum levels of IgG and IgM in neonates through changes in the function of fetal immune system. Furthermore, these alterations are believed to be gender independent.