Pregnancy Outcome According To Elapsing Time After An Immediate Administration Of Antibiotics In A Rabbit Model For The Intrauterine Infection

Moon, Shin Yong; Yoon, Bo Hyun; Syn, Hee Chul; Park, Gyo Hoon

Abstract

OBJECTIVE
In a pregnant rabbit model using hysteroscopy-guided inoculation of E. coli, we investigated pregnancy outcome according to elapsing time with immediate antibiotic treatment after E. coli inoculation, and in turn determined which of the maintenance of pregnancy with antibiotic and tocolytic administration or prompt delivery in the management of preterm labor complicated with intrauterine infection offered the improvement of pregnancy outcome.
METHODS
Timed-pregnant rabbits underwent hysteroscopy at 20-21 days of gestation(70%). Animals were inoculated with either E. coli(0.2 ml containing 10' cfu/ml) or saline, and administered ampicillin-sulbactam(100 mg/kg/day; Unasyn; Pfizer) in divided doses every 8 hours beginning 30 minutes after microbial inoculation until euthanasia with one of the following; 3 days(n 10), 5 days(n 8), or 7 days(n-8) after hysteroscopy. In the first study, which performed in animals with inoculation of E. coli, pregnancy outcome including fetal survival rate and results of microbial studies and placental pathology were compared among three groups. In second study, which performed in animals with inoculation with saline, pregnancy outcome were compared among three groups for the purpose of elucidating effects of antibiotic administration during inoculation-to-euthanasia interval on pregnancy outcome.
RESULTS
Of rabbits inoculated with E. coli and receiving antibiotics immediately, the rate of fetal survival and positive intrauterine cultures in total and live fetuses decreased significantly, and the rate of placental inflammation in total and live fetuses increased significantly with time from intracervical inoculation with E. coli to euthanasia(p<0.05, respectively). Of rabbits inoculated with saline and receiving antibiotics immediately, the rates of fetal survival, positive intrauterine cultures in total and live fetuses, and placental inflammation in total and live fetuses have no difference with time from intracervical inoculation with saline to euthanasia.
CONCLUSION
Fetal complications including fetal death could be induced in utero if persistent subclinical intrauterine infection was present in spite of earlier antibiotics administration initiated after inoculation of E, coli. Therefore, when treating with antibiotics in intrauterine infection, it is needed to observe and monitor the presence of persistent intrauterine infection, and if it is persistent, prompt delivery may be better than maintenance of pregnancy with antibiotic and tocolytic administration for the improvement of pregnancy outcome.