Predictors of human gestational length.

Abstract

Our objective was to identify statistically significant variables that determine the length of human gestation. Multiple linear regression was used to analyze 9355 observations from the Delivery Interview Program, a cross-sectional study conducted from 1977 through 1980 at the Boston Hospital for Women (now called the Brigham and Women's Hospital). Maternal parity, age, and race were found to be the most important variables determining the length of human gestation. Multiparous women, women aged < 19 or > 34 years, and black women were found to have shorter gestations than primiparous women, women aged 19 to 34 years, or white women. By means of our linear model the length of pregnancy for women with different risk factors can be estimated more precisely than Naegele's rule allows.