Pre and post-natal growth canalisation: Does prenatal growth predict the pattern of postnatal growth?

Publication authors

Norris T.; Cameron N.; Johnson W.; Wright J.


Introduction: Identify any evidence of weight growth tracking between intra & extra-uterine life and determine whether patterns of prenatal growth predict patterns of postnatal growth.

Methods: Multilevel models were used to model fetal and postnatal growth from the Born in Bradford (BiB) cohort. Fitted values and Z-scores were produced at 20, 30, 40 prenatal weeks & 1, 3, 6, 9, 12, 24 postnatal months. Restricted and rapid growth were defined as a change in conditional Z-score in the fetal period of <-0.67 and >0.67, respectively. Catchdown and catch-up growth were defined in the same way, except in the postnatal period. ANOVAs were used to test for differences in size and growth by type of prenatal growth. Log regression and a sensitivity and specificity analysis were employed to examine the predictive ability of the type of prenatal growth.

Results: Infants experiencing restricted fetal growth remained significantly lighter than those who had not, for the duration of infancy. In this group however, there was a pattern of greater growth than expected during infancy. This was opposite to the pattern observed in infants who had experienced rapid fetal growth, who exhibited less growth than expected during infancy. However, the ability of the type of prenatal growth to predict the pattern of postnatal growth was minimal, with only rapid fetal growth being significantly associated with increased odds of catchdown growth in infancy.

Conclusion: That neither restricted nor rapid fetal growth predicted postnatal catch-up growth may suggest that the timing of canalisation is outside of the fetal period. If infant catch-up and down growth are not associated with periods of restricted or rapid fetal growth, definitions of these growth patterns may need reconsidering.