The ponderal index in triplets: IV. Relationship with maternal height.

The purpose of the study was to further evaluate the relationship between maternal height and neonatal ponderal index and length. A total of 774 triplet sets with matched maternal stature was available for analyses. We found a significant correlation between maternal height and infant length for both nulliparas (R2=0.70, p=0.04) and multiparas (R2=0.99, p=0.00005). The slopes of the regressions were different than zero, but the difference between the respective regressions was not significant (p=0.83). The analysis revealed a significant correlation between infant ponderal index and maternal stature for nulliparas (R2=0.68, p=0.04) but not for the multiparas (R2=0.08, p=0.6). The slope of the regression for nulliparas was different than zero, but that for the nulliparas was not. The difference between the respective regressions was significant (p=0.03). We conclude that taller mothers deliver longer infants, irrespective of parity, whereas the effect of maternal height on the ponderal index is parity-dependent.