Maternal weight status and term birth weight in first and second adolescent pregnancies.

The relationship of maternal weight status to birth weight was evaluated retrospectively for the first and second pregnancies of 72 younger (age 12-15 years at first conception) and 80 older (age 16-19 years at first conception) low-income adolescents (76% black, 24% white). Mean birth weight increased during the second pregnancies of both groups (277 g and 132 g, respectively). Multiple regression analysis (controlling for potentially confounding variables) indicated a positive relationship between second and third trimester rate of maternal weight gain (kg/week) and birth weight for younger adolescents during their second pregnancy (p = 0.014), and for older adolescents during their first pregnancy (p = 0.047). Mean birth weight increased with each increase in maternal weight-for-height (W/H) category near term from the lowest (< 100% of standard) to the highest (> or = 140% of standard), for both age groups during both pregnancies. Multiple regression analysis indicated that among older adolescents birth weight increased 4.2 +/- 2.0 g (X +/- SE) for each 1% increase in maternal W/H near term in their first pregnancy (p = 0.038) and 7.1 +/- 1.8 g for each 1% increase in maternal W/H near term in their second pregnancy (p = 0.0003). Among younger adolescents these relationships, while in the same direction, were not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)