Association of very high Hungarian rate of preterm births with cervical incompetence in pregnant women.

BACKGROUND Maternal cervical incompetence in pregnancy (CIP) showed an association with a higher rate of preterm births. The objective of this study was to determine the prevalence of CIP in Hungarian pregnant women, to determine the rate of preterm birth, and to check the preventive efficacy of preterm births due to CIP by therapeutic cerclage or bed rest alone. METHODS Analysis of the population-based large data set of 38,151 newborns (without any defects) of the Hungarian Case-Control Surveillance System of Congenital Abnormalities (HCCSCA), born during 1980-1996, i.e. 1.8% of Hungarian newborns. Prospective cohort analysis based on medically recorded variables of CIP, birth weight and gestational age. RESULTS A total of 2,795 (7.33%) newborns born to mothers with CIP. The newborns of mothers with CIP had a shorter gestational age at delivery (39.0 wk) and higher rate of preterm birth (11.1%) than the Hungarian reference sample without CIP (39.4 wk and 9.0%). Of 2,795 pregnant women with CIP 1,112 were treated by cerclage, while 1,683 with bed rest alone. The mean gestational age was shorter both after therapeutic cerclage (39.2 wk) and particularly bed rest alone (38.9 wk). The rate of preterm births was 9.1% and 12.7% after therapeutic cerclage and bed rest alone. CONCLUSIONS CIP is very frequent in Hungary probably due the extremely high number of previous induced abortion performed by dilatation and curettage method. CIP associates with an increased risk for preterm births; however, this increased risk was reduced by bed rest alone and mainly by therapeutic cerclage.