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The Incidence of Histological Chorioamnionitis in IVF/GIFT Preterm Births
Author(s) -
Williams Heather,
Jeffery Heather
Publication year - 1994
Publication title -
australian and new zealand journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.734
H-Index - 65
eISSN - 1479-828X
pISSN - 0004-8666
DOI - 10.1111/j.1479-828x.1994.tb01277.x
Subject(s) - chorioamnionitis , medicine , incidence (geometry) , obstetrics , subclinical infection , gestation , gestational age , pregnancy , population , gynecology , biology , genetics , physics , environmental health , optics
EDITORIAL COMMENT: We have accepted this paper for publication to inform readers of the high prevalence of chorioamnionitis in both IVF and GIFT pregnancies, and in normal singleton pregnancies that deliver before 37 weeks' gestation. It could be advantageous to analyse the incidence of chorioamnionitis in IVF pregnancies and GIFT pregnancies separately since the women treated by GIFT have patent tubes and presumably a different past history in terms of chorioamnionitis. It is also important to know the incidence of chorioamnionitis in term singleton pregnancies and in IVF and GIFT term pregnancies before one can make deductions regarding chorioamnionitis being a cause of preterm birth. Readers are referred to the other paper in this issue of chorioamnionitis associated with Ureaplasma urealyticum. Authors' response to editorial comment : We believe that the data presented suggests that subclinical infection/inflammation although it does not explain the 4‐fold increase in preterm births in the IVF/GIFT population may contribute to between one quarter and one third of the preterm births in both the IVF/GIFT and the control groups of less than 35 weeks gestational age. We were unable to study the incidence of chorioamnionitis in IVF/GIFT pregnancies that were not delivered prematurely but consider that from the literature and Russell's paper (8) the incidence of chorioamnionitis in term infants is less than 10% and probably less than 5 %. Accordingly chorioamnionitis is likely to be an important cause of preterm birth. Summary: A retrospective case control study was designed to investigate the role of subclinical infection as a risk factor for the high rate of preterm deliveries in IVF/GIFT pregnancies. The cases and the controls were identified from the records of consecutive livebirths of <35 weeks' gestational age (GA), at King George V Hospital from 1987–1993. Fifty one singleton and 58 twin IVF/GIFT preterm births were matched for GA, year of birth, plurality, maternal age, parity, preclampsia and antepartum haemorrhage. As a marker of subclinical infection, the incidence of histological chorioamnionitis (HCA) in the 2 groups (as defined by the standardized, semiquantitative method of Benirschke) was compared. The matched variables did not differ significantly between the IVF/GIFT group and the control group. No significant difference in the incidence of HCA was detected between IVF/GIFT and control groups for singletons or twins. Overall 24% of IVF/GIFT and 30% of controls showed evidence of HCA, odds ratio (95% confidence intervals), 0.72 (0.40‐1.31). This study showed no evidence that the incidence of HCA, is significantly increased in IVF/GIFT preterm births compared with other matched, preterm births. Therefore, we conclude that subclinical infection/inflammation cannot explain the 4‐fold increase in preterm births in the IVF/GIFT population.