PHYSICAL GROWTH OF LOW-BIRTH-WEIGHT INFANTS IN THE FIRST YEAR OF LIFE- IMPACT OF MATERNAL BEHAVIORS

Physical growth of preterm infants relates to many medical factors, su ch as birthweight, severity of medical illnesses, and nutritional stat us. We previously reported that maternal behaviors influence developme ntal outcomes in low birthweight infants (birthweight < 1600 g); we no w hypothesize that maternal behaviors also influence physical somatic growth in low birthweight (LBW) infants. We serially followed 218 moth er-infant pairs from birth through 12 months of age. One-hundred thirt een LBW infants were categorized based on severity of early medical co mplications. Low Risk infants (LR, n = 71) had acute respiratory distr ess and/or grade 1-2 intraventricular hemorrhage (IVH), or grade 3 IVH without hydrocephalus. High Risk infants (HR, pi = 42) had chronic lu ng disease, grade 3 IVH with hydrocephalus or grade 4 IVH, and/or peri ventricular leukomalacia. We also studied 105 socioeconomic (SES) matc hed Pull Term (FT) controls. Maternal behaviors were assessed during h ome visits with global ratings of Warm Sensitivity and Punitiveness. I nfant weight was measured at birth and at 38 weeks, 6 months and 12 mo nths corrected gestational age. We examined alternative expressions of weight growth across the three groups by developing the Weight Quotie nt (WQ), which is the ratio of actual measured weight to the median we ight for age. For each infant the regression of the WQ ratio against c orrect gestational age was analyzed. We used a General Linear Model to compare the relation of the maternal variables to the weight quotient s for the three groups. We determined the catch up growth as the slope of each regression. Results indicated that higher levels of maternal Punitiveness were related to slower rates of growth for High Risk (R-2 = 0.36), but not Low Risk or Full Term. For maternal Warm Sensitivity (R-2 = 0.36), there were significant (P < 0.05) inverse relations wit h weight gain growth for the Full Term infants. These data suggest tha t some maternal behaviors are related to the growth of term and premat ure infants, although the mechanisms through which this occurs is uncl ear.