Grant: CIHR Fellowship

Infants born too small or too large for their length of gestation are known to be at higher risk of neonatal complications and long-term handicaps. Despite the important role that size at birth plays in the health of newborns, commonly used methods to identify abnormal size at birth are solely based on information of the length of gestation and birthweight. However, increasing evidence suggests that this approach results in substantial misclassification, mainly because fetal growth is multifactorial, and not fully addressed by the information provided by length of gestation and birthweight alone. Determinants of fetal growth include numerous maternal and fetal conditions arising during pregnancy that are not taken into account. Failure to consider these influences may result in inaccurate classification of abnormal size at birth. The consequence is that in many cases babies not correctly classified may be subject to underintervention or overintervention, thus translating into suboptimal care and not very efficient use of the available material resources. The objectives of this research program are to develop new methods to identify abnormal newborn size, and to assess the capacity of these new methods to identify infants at high risk of poor health, and/or in greater need of healthcare resources. Linked administrative health care databases in Ontario will be used to bring together a wide array of maternal and fetal factors deemed to affect fetal growth and innovative statistical methods to analyze more than one million infants born since 2002. These new methods could be used to refine perinatal surveillance using linked Canadian administrative and other population -based databases. The findings may alter how we intervene in the care of a newborn when that newborn is incorrectly or correctly classified as too small or too large for gestational age.