In a cross-sectional study of 87 large-for-menstrual-age term infants, intrauterine growth was found to be linear, 34 g per day. Differences between diabetic and nondiabetic pregnancies were not evident. Indexing Words: Fetal growth Large for menstrual age Diabetic gravida Most fetal weight gain occurs in the third mass is disproportionally increased, is reported trimester. Extrapolation from tables for live-in diabetic gravidas, classes A, B, and C.' born infants reveals that the fetus, both large Using ultrasound, we determined daily fetal and small, gains 15 to 30 glday between 27 and growth of large-for-menstrual-age fetuses during 39 weeks and 3-9 glday However, the third trimester. Differences between diabetic the use of data for live-born infants to predict in and nondiabetic pregnancies were evaluated. utero growth has been questioned.
Ultrasound has been used extensively to predict fetal weight. Ott and Doyle found that a normal size fetus grew by 28 glday between 30 and 35 weeks and 12 glday thereafter.3 Miller et al. found fetal growth to decrease gradually from 42 glday at 33 weeks to 8 glday at 42 weeks.4 Differences among small-, average-, and large-formenstrual-age fetuses were not appreciated. However, a longitudinal study revealed that above average sized infants grow at 72 glday.5
Reports specific for growth rates of large-formentrual-age fetuses are lacking. However, recent studies suggest that in diabetic pregnancies, accelerated fetal growth is different from that seen in the fetus of a nondiabetic ~a t i e n t . ~" Two forms of accelerated growth, symmetric and asymmetric,6 have been described.' If excessive fetal weight is the result of proportional growth of all variables, the result is symmetric macrosomia, thought to be genetic and repetitive. Asymmetric macrosomia, in which soft tissue From the Departments of