Birthweight standards in the live-born population in Israel

Background: Lacking curves of "intrauterine" growth, most birthing centers in Israel use United States or Canadian based curves as standards. Objective: To establish population-based standards of birth weight of live-born infants in Israel. Methods: Data on birth weight and gestational age were obtained from the registries of the Israel Ministry of Health and Ministry of the Interior. During the 9 year study period there were 1,074,122 infants delivered in Israel; 787,710 (73%) were included in this analysis. Results: In this study we provide data of birth weight by gestational age of live infants born in Israel between 1993 and 2001. Ranges of birth weight by gestational age are also depicted for singleton and multiple pregnancies. Fetuses in multiple pregnancies grow in a similar manner to singletons until 30 weeks of gestation, after which their growth slows down. Conclusions: Use of these data as a standard for "intrauterine" growth better represents the Israeli neonatal population than the North American standards. In addition, curves of multiple pregnancies are significantly different from those of singleton pregnancies and might be more appropriate in these pregnancies.