Placental transfer of tetanus-specific immunoglobulin G in Iranian mothers.
OBJECTIVE
To investigate placental transfer of anti-tetanus immunoglobulin (Ig)G antibodies in Iranian mothers.


METHODS
Sera collected from 209 pregnant women and their paired infants were evaluated for tetanus-specific antibodies by a commercial enzyme-linked immunosorbent assay.


RESULTS
In total, 15 (7.2%) out of 209 mothers and 12 (5.7%) out of 209 newborns were negative for anti-tetanus IgG. A highly significant correlation was observed between maternal and fetal anti-tetanus IgG (r = 0.80). The mean cord/maternal blood ratio of anti-tetanus IgG was 1.22 +/- 0.97. The mean cord/maternal blood ratio of anti-tetanus IgG in mothers with blood groups B+ and AB+ was lower than in mothers with other blood groups (p = 0.027). In addition, among mothers who had more than 0.5 IU/ml anti-tetanus IgG, a higher percentage of cases with cord/maternal blood ratio of < 1 was observed in carriers of blood groups B+ and AB+ compared to those with other blood groups (45.2% vs. 41.8%). Parity of more than 4 had a significant negative effect on both frequency of high positive sera and the mean of anti-tetanus IgG level in maternal and neonatal sera.


CONCLUSIONS
A relatively high percentage of pregnant women were not immune against tetanus. It was also found that the main factors that affect infants' tetanus-specific IgG are maternal concentration of this immunoglobulin, parity and maternal blood group.
Samsami Dehaghani
A
A
Department of Obstetrics and Gynecology, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran.
Doroudchi
M
M
Ghaderi
A
A
D000017:ABO Blood-Group System / Q000276:immunology; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D000918:Antibody Specificity; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007231:Infant, Newborn; D007492:Iran; D008431:Maternal-Fetal Exchange; D010298:Parity; D011247:Pregnancy; D013742:Tetanus / Q000276:immunology*
D000017:ABO Blood-Group System; D000907:Antibodies, Bacterial; D007074:Immunoglobulin G