Increased time to pregnancy is associated with less optimal neurological condition in 4-year-old singletons, in vitro fertilization itself is not.

STUDY QUESTION: Does ovarian hyperstimulation, the in vitro procedures required for in vitro fertilization (IVF)/ intracytoplasmic sperm injection or the combination of both, affect the neurological outcome of 4-year-old singletons? SUMMARY ANSWER: Ovarian hyperstimulation, the in vitro procedure and the combination of both, were not associated with the worse neurological outcome in 4-year-old singletons. WHAT IS KNOWN ALREADY: Assisted reproduction techniques (ARTs) are not associated with neurological dysfunction during the first post-natal years; however, effects on the long-term neurological outcome are still inconclusive. An increased time to pregnancy (TTP, a proxy for the severity of subfertility) has been associated with a less optimal neurological condition at age 2. The present study focuses on the neurodevelopmental outcome of 4-year-old ART-offspring. STUDY DESIGN, SIZE, DURATION: Longitudinal, prospective follow-up study. PARTICIPANTS, SETTING, METHODS: Four-year-old singletons born to subfertile parents (subfertile group, n = 195), including singletons born after controlled ovarian hyperstimulation IVF (COH-IVF, n = 63), modified natural cycle IVF (MNC-IVF, n = 53) and natural conception (Sub-NC, n = 79). Data on underlying cause of subfertility and TTP were present. In addition, we assessed newly recruited 4-year-old singletons born to fertile parents after natural conception (reference group, n = 98). Neurological development was evaluated with the neurological examination according to Hempel, resulting in a neurological optimality score (NOS), a fluency score and the occurrence of the clinically relevant form of minor neurological dysfunction (complex MND). The primary outcome was the fluency score, as fluency of movements is easily reduced by subtle brain dysfunction. Data were analysed with univariable and multivariable regression analyses, in which special attention was paid to sex differences in the neurological outcome. MAIN RESULTS AND THE ROLE OF CHANCE: The fluency score, NOS and the prevalence of complex MND were similar in COH-IVF, MNC-IVF and Sub-NC children. The neurological condition of children born to subfertile parents was similar to that of children of fertile parents and was independent of the underlying cause of subfertility. No statistically significant associations were found between TTP and the fluency score and NOS. However, a positive correlation was found between TTP and the prevalence of complex MND (TTP in years, adjusted odds ratio [OR] [95% confidence interval, CI]: 1.207 [1.038 to 1.404], P = 0.014); a correlation which could be attributed to girls, in whom an evident positive correlation was present (adjusted OR [95% CI]: 1.542 [1.161 to 2.047], P = 0.003). A similar association was absent in boys. LIMITATIONS, REASONS FOR CAUTION: The prospective design of our study and small post-natal attrition rate (9.3%) reduced potential selection bias based on the child's development or health. The assessors were blind to the mode of conception, except for the group of children born to fertile parents, which was newly recruited. The study lacks sufficient power to conclude firmly that increased TTP is associated with a higher prevalence of complex MND. WIDER IMPLICATIONS OF THE FINDINGS: Our study suggests that the severity of subfertility, rather than its simple presence or components of IVF treatment, affects the neurological outcome. Moreover, girls may be neurologically more vulnerable for the effect of severity of subfertility. The finding that the severity of subfertility may be the decisive factor rather than the presence of a history of subfertility per se corroborates previous reports. Our results cannot be generalized to multiples, as we studied singletons only. STUDY FUNDING/COMPETING INTERESTS: The study was financially supported by the University Medical Center Groningen, grant number: 754510, the Junior Scientific Masterclass, the Postgraduate School Behavioural and Cognitive Neurosciences and the Cornelia Foundation, Groningen, The Netherlands. The authors have no conflicts of interest to declare.

The effect of preimplantation genetic screening on neurological, cognitive and behavioural development in 4-year-old children: follow-up of a RCT.

STUDY QUESTION: Does embryo biopsy inherent to preimplantation genetic screening (PGS) affect neurological, cognitive and behavioural development of 4-year-old children? SUMMARY ANSWER: PGS does not seem to affect neurological, cognitive and behavioural development of 4-year-old singletons; however, our data suggest that it may be associated with altered neurodevelopment in twins. WHAT IS KNOWN ALREADY: Evidence concerning the safety of PGS on neurodevelopmental outcome in offspring is scarce. The present study provides information on neurodevelopmental, cognitive and behavioural outcome of 4-year-old PGS offspring. STUDY DESIGN, SIZE, DURATION: A prospective, assessor-blinded follow-up study of children born to women who participated in a multi-centre RCT on the effect of IVF with or without PGS. PARTICIPANTS/MATERIALS, SETTING, METHODS: At 4 years, 49 children (31 singletons, 9 sets of twins) born following IVF with PGS and 64 children (42 singletons, 11 sets of twins) born following IVF without PGS (controls) were assessed (post-natal attrition 18%). Neurological development was evaluated with the standardized, age-specific and sensitive neurological examination according to Hempel, resulting in a neurological optimality score (NOS), a fluency score and the rate of adverse neurological outcome. Primary outcome was the fluency score, as fluency of movements is easily reduced by subtle dysfunction of the brain. Cognitive development was evaluated with the Kaufman Assessment Battery for Children; behavioural development was evaluated with the Child Behavior Checklist. The effect of PGS was analysed with a mixed effects model. MAIN RESULTS AND THE ROLE OF CHANCE: Based on the intention to treat analysis, neurodevelopmental outcome of PGS children was similar to that of controls. However, additional analyses indicated that PGS affected neurodevelopmental outcome of twins in a different way than that of singletons. The fluency score of singletons born following PGS was similar to that of control singletons [mean values, 95% confidence intervals (CIs): 12.2 (11.5;12.8) and 12.2 (11.6;12.8)], respectively, P = 0.977) that was also true for the other neurodevelopmental parameters. The fluency score of PGS twins was significantly lower than that of control twins [mean values, 95% CIs: 10.6 (9.8;11.3) and 12.3 (11.5;13.1)], respectively, P = 0.001); the same was true for the NOS. In addition, PGS in twins was associated with a higher sequential intelligence quotient score. On the other hand, other neurodevelopmental parameters were similar for PGS twins and control twins. Post hoc sample size calculation for the primary outcome parameter, the fluency score, indicated that the study groups, including the subgroups of singletons and twins, were adequately powered. LIMITATIONS, REASONS FOR CAUTION: We assessed singletons and twins who contributed to the generalizability of the study. A limitation of our study is the relative small size of our study groups and the selective dropout in both groups (dropouts PGS group: higher gestational age; control group: less well-educated parents). These preclude the conclusion that PGS per se is not associated with neurodevelopmental, cognitive and behavioural problems in singletons and the conclusion that PGS is associated with altered neurodevelopmental outcome in twins. WIDER IMPLICATIONS OF THE FINDINGS: The need for careful long-term monitoring of children born following embryo biopsy remains, as it is still applied in the form of PGD and it is still unknown whether embryo biopsy affects long-term neurodevelopmental outcome.

The Groningen ART cohort study: the effects of ovarian hyperstimulation and the IVF laboratory procedures on neurological condition at 2 years.

BACKGROUND: Up to 4% of children are born following assisted reproduction techniques (ART) yet relatively little is known on neurodevelopmental outcome of these children after 18 months of age. Only a limited number of long-term follow-up studies with adequate methodological quality have been reported. Our aim was to evaluate the effects of ovarian hyperstimulation, IVF laboratory procedures and a history of subfertility on neurological condition at 2 years. METHODS: Singletons born after controlled ovarian hyperstimulation IVF (COH-IVF, n = 66), modified natural cycle IVF (MNC-IVF, n = 56), natural conception in subfertile couples (Sub-NC, n = 87) and in fertile couples (reference group, n = 101) were assessed (using Hempel approach) by neurological examination at 2 years of age. This resulted in a neurological optimality score (NOS), a fluency score and the prevalence of minor neurological dysfunction (MND). Primary outcome was the fluency score, as fluency of movements is easily affected by subtle dysfunction of the nervous system. RESULTS: Fluency score, NOS and prevalence of MND were similar in COH-IVF, MNC-IVF and Sub-NC children. However, the fluency score (P < 0.01) and NOS (P < 0.001) of the three subfertile groups were higher, and the prevalence of MND was lower (P = 0.045), than those in the reference group. CONCLUSIONS: Neurological condition of 2 year olds born after ART is similar to that of children of subfertile couples conceived naturally. Moreover, subfertility does not seem to be associated with a worse neurological outcome. These findings are reassuring, but we have to keep in mind that subtle neurodevelopmental disorders may emerge as children grow older.