STRIDER NZAus childhood outcomes study

STRIDER stands for Sildenafil TheRapy In Dismal prognosis Early onset intrauterine growth Restriction.The Childhood Outcome Study is an early childhood follow-up study to STRIDER NZAus, a placebo-controlled randomised trial of antenatal sildenafil therapy for severe, early-onset growth restriction.

The STRIDER NZAus Childhood Outcome Study follows up the cohort of surviving children born to mothers who took part in the STRIDER NZAus trial. We aim to determine whether any benefit (or harm) seen in the newborn as a consequence of antenatal sildenafil therapy is sustained, or develops, through childhood.

What is this study trying to find out?

Children will be assessed at 2-3 years of age to provide critical information on their neurosensory, cognitive, and emotional-behavioural development; their cardio-metabolic and respiratory well-being; and information on their general health. We will compare the children born to mothers treated with sildenafil to the children born to mothers treated with placebo.
Our primary hypothesis is that at 2.5 years corrected age, children whose mothers received antenatal sildenafil therapy compared with those who received placebo will have improved survival and neurodevelopmental outcome.

How will children be assessed?

Children in the study will be assessed at 2 to 3 years’ corrected age by a paediatrician and psychologist:

  • The paediatric review will include measurement of growth, blood pressure, movement and reflexes, a hearing and vision assessment, and questions about general health and medication use.
  • A psychologist or developmental assessor will conduct a Bayley III exam (where this has not been conducted as part of the child’s routine follow up).
  • Parents will be asked to complete a number of questionnaires about the child’s behaviour, health and home life (including the BRIEF-P, CBCL and ITQOL questionnaires).

Potential study outcomes

If sildenafil is shown to be effective for the treatment of early onset IUGR (the most severe form), its use could be extended to the later stages of pregnancy, when although associated with less severe effects for each baby, the condition is more common and so the potential overall effect is greater. This study will generate important Australasian data on neuro-developmental and health outcomes of children born with severe preterm IUGR.

The results are also relevant to other areas of perinatal care as sildenafil is increasingly used in pregnancy and in the management of newborn babies with very little knowledge on fetal, neonatal and long–term health. Follow-up of STRIDER NZAus children through childhood will provide essential and reliable safety and outcome data which can be considered before any extension of the use of this drug in pregnancy and to allow further investigation into its therapeutic potential.


Follow up of the last children born to mothers who participated in STRIDER NZAus is expected to be complete by late 2019.