The relationship of maternal attitude toward weight gain to weight gain during pregnancy and low birth weight.

OBJECTIVE: To evaluate the relationships between maternal attitude toward weight gain, actual weight gain, and infant birth weight.

METHODS: Maternal attitude toward weight gain during pregnancy was assessed in 1000 women, using an 18-item questionnaire administered at a mean of 20 weeks' gestation. Composite scores were compared with pregnancy weight gain, maternal body mass index (BMI), and infant birth weight.

RESULTS: In the total population, the attitude score was not significantly related to pregnancy weight gain (r = -0.05, P = .08) and was negatively associated with birth weight (r = -0.09, P < .004). Maternal body size as measured by BMI was strongly associated with both weight gain and birth weight. Obese women (BMI greater than 26.6) tended to have negative attitudes and had the lowest mean weight gain (10.2 kg), but had the heaviest babies (3400 g). Thin women (BMI less than 19.6) had significantly higher attitude scores and a higher mean weight gain (14.1 kg) than did obese women. A significantly larger proportion of thin women achieved recommended gains when compared with larger women, but had the lightest babies (3114 g). Within the group of thin women, after adjustment for smoking, race, and gestational age at delivery, attitude scores were not significantly associated with either weight gain or birth weight.

CONCLUSION: Maternal attitude regarding weight gain is strongly influenced by pre-pregnancy body size; thin women tend to have positive attitudes and obese women tend to have negative attitudes about weight gain. Within BMI groups, a positive attitude does not predict appropriate weight gain or birth weight. These findings may explain in part why nutritional counseling programs tend to be associated with only minimal increases in birth weight.