Serotypes of Ureaplasma urealyticum isolated from normal pregnant women and patients with pregnancy complications.

To compare the distribution of Ureaplasma urealyticum serotypes 1 to 10 in different patient populations, the serotypes of 240 U. urealyticum strains from 207 patients were determined by the indirect immunofluorescence test by using U. urealyticum antisera 1 to 10. Strains were obtained from the following four patient groups: group 1, 24 couples in which the women had a history of recurrent spontaneous abortion; group 2, 25 patients who had their first spontaneous abortion; group 3, 14 pregnant patients with pregnancy complications (premature delivery, intrauterine death); and group 4, 138 patients with uneventful pregnancies. The serotypes most often found in these 207 patients were as follows: serotype 3, 52.2%; serotype 6, 30.3%; serotype 10, 11.4%; serotype 1, 9.5%; serotype 4, 6.5%; serotype 8, 6.5%. Serotypes 2, 5, 7, and 9 were found in less than 1% of the patients. More than one serotype was found in 16.9% of the patients. The overall distribution of the 10 serotypes in the different groups was similar, except for that of serotype 4. Serotype 4 was isolated from 20.8% of the patients in group 1 and from 5.1% of the patients in group 4 (P less than 0.01). Results of this study indicate that U. urealyticum serotype 4 can be isolated more frequently from patients with a history of recurrent miscarriages than from normal pregnant women.