Challenges of neurodevelopmental follow-up for extremely preterm infants at two years

This study examined the rates of follow-up for a cohort of extremely preterm (EP -<28weeks gestation) and/or extremely low birthweight (ELBW -<1000g) children at two years with related perinatal and geographical factors. The secondary aim was to determine the rates of developmental delay and disability.

A retrospective review of two year follow-up data for all EP and/or ELBW infants born in a large tertiary neonatal hospital over a two year period was undertaken. Neurodevelopmental outcome was assessed using the Bayley Scales of Infant and Toddler Development Scale - 3rd edition (Bayley-III) and neurosensory disability was assessed by a paediatrician using a standard proforma. Rates of delay (composite score≥1SD below mean) were determined using the Bayley-III test norms and a local cohort normative group. Attrition rates and reasons for loss to follow-up were determined.

Only 50% (109/219) of eligible children participated in the follow-up. The follow-up rate for children engaged in an ongoing research project was excellent at 98% (58/59), however it was only 32% (51/160) for children following the clinical pathway. The main reason for not attending the follow-up was loss of contact. Factors associated with attendance included a lower gestation, sepsis and living in the metropolitan areas. The rates of delay in this cohort were greater with reference to local cohort normative data compared to Bayley-III test norms with an overall rate of delay of 72% (95%CI, 63% to 81%) compared to 38% (95%CI, 29% to 50%).

Follow-up of EP/ELBW infants to two years is an important part of clinical care, however the high rate of attrition in routine clinical follow-up and consequent difficulty in accurately determining rates of delay highlight challenges for centres providing ongoing care.