Incidence of infants born small- and large-for-gestational-age in an Italian cohort over a 20-year period and associated risk factors

BACKGROUND: We assessed the incidence of infants born small-for-gestational-age (SGA) and large-for-gestational-age (LGA) in an Italian cohort over 20 years (1993-2013). Furthermore, we investigated maternal factors associated with SGA and LGA births. METHODS: A retrospective review of obstetric records was performed on infants born in Chieti (Italy) covering every 5(th) year over a 20-year period, specifically examining data for 1993, 1998, 2003, 2008, and 2013. Infants with birthweight <10(th) percentile were defined as SGA, and those with birthweight >90(th) percentile as LGA. Data collected included newborn anthropometry, birth (multiple vs singleton), maternal anthropometry, previous miscarriage, gestational diabetes, hypertension, and smoking during pregnancy. RESULTS: There were a pooled total of 5896 live births recorded across the 5 selected years. The number of SGA (+60.6 %) and LGA (+90.2 %) births increased considerably between 1993 and 2013. However, there were no marked changes in the incidence of SGA or LGA births (8.3 % and 10.8 % in 1993 versus 7.6 % and 11.7 % in 2013, respectively). Maternal factors associated with increased risk of SGA infants included hypertension, smoking, and previous miscarriage (all p < 0.05), while greater pre-pregnancy BMI and gestational diabetes were risk factors for LGA births (all p < 0.05).