Survey of early preterm singleton live births in Iwate Prefecture as a provincial model of the medical situation in Japan

Abstract

Aim: The aim of this study was to survey early preterm (prior to 32 weeks' gestation) singleton live births in Iwate Prefecture as a provincial model of the medical situation in Japan.

Materials and methods: Data from 177 early preterm singleton live births, and 31,445 total live births (January 2005-December 2007) in Iwate Prefecture Japan were used to analyze the incidence of early preterm singleton live birth in each medical service area.

Results: The incidence of spontaneous early preterm singleton live birth did not differ between the coastal and inland medical service areas (3.35 vs 3.57 per 1000 live births). In the Morioka medical service area (radius about 40 km), the incidence of spontaneous early preterm singleton live birth in municipalities without obstetric care facilities was significantly higher than that in municipalities with obstetric care facilities (6.62 vs 2.65 per 1000 live births, P < 0.005). The incidence of early preterm singleton live birth due to pregnancy-induced hypertension in the coastal medical service areas was higher than that in the inland areas (1.67 vs 0.71 per 1000 live births, P < 0.05).

Conclusions: In Iwate Prefecture, Japan, the incidence of singleton preterm live birth before 32 weeks of pregnancy varies among its constituent medical service areas according to geographic factors as well as the availability of obstetric care facilities.