Movement variation in infants born following IVF/ICSI with and without ovarian hyperstimulation

Background. The effect of in vitro fertilisation (IVF) on neurodevelopment is not fully understood. Probably, IVF does not affect traditional measures of neurodevelopment in infancy. Recently, an instrument, the Infant Motor Profile (IMP), was developed that evaluates the quality of motor behaviour. It includes the evaluation of movement variation (i.e. movement repertoire size), a parameter reflecting the integrity of cortical connectivity. Aim. To evaluate the effect of ovarian hyperstimulation and the in vitro procedure on movement variation during infancy. Study design. Prospective cohort study. Subjects. Singletons born following IVF or intracytoplasmic sperm injection (ICSI) with conventional controlled ovarian hyperstimulation (COH-IVF/ICSI, n = 68), in a modified natural cycle (MNC-IVF/ICSI, n = 57) and natural conception born to subfertile couples (Sub-NC, n = 90). Outcome measures. Children were assessed with the IMP at 4, 10 and 18 months, resulting in a total IMP score and five domain scores: variation, variability, symmetry, fluency and performance. Primary outcome was the domain score variation. Results. A significant effect of study group was observed for the variation score up until 18 months of age (p = 0.039). COH-IVF/ICSI children had a significantly lower mean variation score than MNC-IVF/ICSI children (mean difference [95% confidence interval] - 1.010 [- 1.766; - 0.254]). Mean variation scores of COH-IVF/ICSI and Sub-NC children were similar; the same held true for the comparison between MNC-IVF/ICSI and Sub-NC. Total IMP scores and other domain scores of the three groups were similar. Conclusion. The present study did not demonstrate a clear effect of ovarian hyperstimulation and the in vitro procedure on movement variation throughout infancy. Keywords: In vitro fertilisation; Ovarian hyperstimulation; Neurodevelopmental outcome; Variation; Follow-u