Do tall women beget larger babies?

Abstract

Objective: To evaluate the possible relationship between maternal height and fetal size.

Patients and methods: We used a population-based cohort of apparently healthy mothers of singletons to evaluate quartiles of the maternal height distribution for parity, being overweight or obese, and for gestational age and birth weight parameters. We also generated birth weight by gestational age curves for each quartile.

Results: We analyzed data of 198,745 mothers. Mother from the four quartiles had similar parity, pre-gravid BMI, and gestational age at birth. Short mothers had a significantly higher rate of VLBW and LBW and 2501-4000 g infants, for an OR = 1.38 (95% CI: 1.17-1.62), OR = 2.2 (95% CI: 2.05-2.37) and OR = 1.82 (95% CI: 1.73-1.87) between the shortest and tallest mothers, respectively. By contrast, the opposite trend was noticed for birth weights >4000 g, for an OR = 2.77 (95% CI: 2.65-2.89) between the tallest and shortest mothers. A very similar "growth curve" was apparent until 33 weeks, when a slower growth velocity was observed for shorter compared with taller women.

Conclusions: Maternal stature does not appear to be associated with gestational age but significantly influences birth weight. Height-related differences between mothers appears to begin after 33 weeks' gestation.

Keywords: Birth weight; maternal height; pre-gravid BMI.