[Experimental intrauterine growth retardation with indomethacin]

The present study was undertaken to determine the influence of indomethacin, a potent inhibitor of prostaglandin synthetase, on the intrauterine fetal growth of rats. All experimental rats administered indomethacin on various days of gestation were sacrificed on day 22 of gestation. The following results were obtained. The intrauterine fetal growth retardation (IUGR) and maternal weight loss were found following intramuscular administration of indomethacin 2mg on day 19 of gestation. IUGR and maternal weight loss were also found after fasting from day 19 of gestation to day 22. IUGR was induced by the administration of indomethacin on days 15 to 21 of gestation, while not by that on day 10. The mean fetal weight of rats which received indomethacin on day 19 of gestation was 3.57 +/- 0.44g, which was as low as 67.9% of normal fetal weight. There seemed to be a critical period for the occurrence of IUGR in rat due to indomethacin. The possible jeopardy of fetal development due to the administration of indomethacin to pregnant women in the late pregnancy should be warned against.