[A study on ways of intrauterine infection of chlamydia trachomatis]

To study the route of intrauterine infection of chlamydia trachomatis (CT).

Seven hundred and seventy-two cervical samples from in women and 105 matched maternal-labom neonatal samples composed of cervical samples, cord blood, amniotic fluid, conjunctival and nasopharyngeal samples of neonate were detected by PCR-SSCP and DNA sequencing technique.

CT were detected in 87 of 772 (11.3%) cervical samples. In the 81 matched maternal-infant samples from pregnant women with cervical CT-positive, CT were not detected in all of the cord blood samples. In the 30 CT-positive neonatal samples, 26 were from cases of vaginal delivery and 4 from cases of caesarean section. Statistical analysis showed a significant difference between the groups of caesarean section and the vaginal delivery (P < 0.01). Four of 11 amniotic fluid samples with CT-positive were obtained during caesarean section in which 3 were without premature rupture of membranes (PROM), SSCP patients were same between maternal samples and matched neonatal samples. The sequences of amplified DNA fragments also showed the same results between maternal and match neonatal samples. No samples were found CT-positive in 24 matched maternal-infant samples from cervical CT-negative women.

An ascending transmission from cervix to amniotic cavity was the major route for CT intrauterine infection. Transplacental passage of chlamydial infection was not confirmed. Rates of vertical transmission were significantly lower in caesarean section group than that of vaginal delivery group with maternal cervical chlamydial positive.