In vitro fertilization and late preterm preschoolers' neuropsychological outcomes: the PETIT study

In vitro fertilization (IVF) is considered a generally safe procedure, although associated with a higher incidence of preterm birth. The literature is inconsistent about the psychological impact of IVF, and we found no reports about outcome in late preterm (LPT) children. Our objective was to study neuropsychological and behavioral outcomes in a cohort of preschoolers born LPT between 2004 and 2007.

Participants were 397 LPT children (mean age, 3.8 years) conceived assisted by IVF (n = 105) or non-IVF (n = 292). Standardized performance-based tests of general conceptual ability (intelligence quotient), executive function, focused/selective attention, visual-spatial perception, visual-motor skill, manual dexterity, learning, and memory were administered. Parents completed behavioral and executive function questionnaires.

IVF group characteristics included older maternal age (P < .001), lower birthweight (P < .001), and higher maternal education (P < .001). No main-effect significant group differences were found for any variable after controlling for these variables. However, sex differences were demonstrated for the neuropsychological variables in copying (P > .001), nonverbal reasoning (P = .001), manual dexterity (P = .001), and inhibitory capacity (P = .006), all favoring girls.

Birth following IVF-assisted conception did not increase the risk of intellectual, neuropsychological, or behavioral deficit in LPT preschoolers. As shown in earlier gestational-age participants, girls have selective advantages. These findings should be reassuring for parents who conceive through IVF and deliver infants 1-3 weeks before term gestational age. Future study of these children at elementary school age may detect subtle impairments not yet apparent at age 3 years.