In vitro fertilisation has been around long enough that researchers can now compare developmental and academic achievements between these children and their peers at school age – and a recent study did just that, finding little difference in these milestones between 11 059 IVF-conceived children and 401 654 spontaneously conceived children.
Findings of the research, led by Amber Kennedy, lead author and obstetrician/ gynaecologist at Mercy Hospital for Women at the University of Melbourne, Australia, and colleagues, were published in the journal PLOS Medicine.
“Parents considering IVF and health care professionals can be reassured that the school age developmental and educational outcomes of IVF-conceived children are equivalent to their peers,” said Kennedy.
Some previous researchers linked conception via IVF to an increased risk of congenital abnormalities, autism spectrum disorder, developmental delay and intellectual disability, reports Medscape.
Asked why the current study did not find increased risks, Kennedy said: “Our population included a relatively recent birth cohort, which may explain some differences from previous studies as IVF practices have evolved over time.”
An estimated 8m people worldwide have been conceived through IVF since the first birth in 1978, the researchers says.
Along with senior author Anthea Lindquist, MBBS, Kennedy and colleagues studied 585 659 single births in Victoria, Australia, between 2005 and 2014. They did not include multiple births like twins or triplets.
The investigators compared 4 697 children conceived via IVF and 168 503 others conceived spontaneously using a standard developmental measure, the Australian Early Developmental Census (AEDC).
They also assessed 8 976 children in the IVF group and 333 335 other children on a standard educational measure, the National Assessment Programme–Literacy and Numeracy (NAPLAN).
For example, the developmental census measures developmental vulnerability. Kennedy and colleagues found a 0.3% difference in favour of IVF-conceived children, which statistically was no different than zero.
Similarly, the researchers report that IVF conception had essentially no effect on the overall literacy score, with an adjusted average difference of 0.03.
Not all IVF techniques are the same, and the researches want to take a deeper dive to evaluate any distinctions among them. For example, Kennedy said: “We plan to investigate the same school-aged outcomes after specific IVF-associated techniques.”
Study details
School-age outcomes among IVF-conceived children: A population-wide cohort study
Amber Kennedy, Beverley Vollenhoven, Richard Hiscock, Catharyn Stern, Susan Walker, Jeanie Cheong, Jon Quach, Roxanne Hastie, David Wilkinson, John McBain, Lyle Gurrin, Vivien MacLachlan, Franca Agresta, Anthea Lindquist.
Published in PLOS Medicine on 24 Januar 2023
Abstract
Background
In vitro fertilisation (IVF) is a common mode of conception. Understanding the long-term implications for these children is important. The aim of this study was to determine the causal effect of IVF conception on primary school-age childhood developmental and educational outcomes, compared with outcomes following spontaneous conception.
Methods and findings
Causal inference methods were used to analyse observational data in a way that emulates a target randomised clinical trial. The study cohort comprised statewide linked maternal and childhood administrative data. Participants included singleton infants conceived spontaneously or via IVF, born in Victoria, Australia between 2005 and 2014 and who had school-age developmental and educational outcomes assessed. The exposure examined was conception via IVF, with spontaneous conception the control condition. Two outcome measures were assessed. The first, childhood developmental vulnerability at school entry (age 4 to 6), was assessed using the Australian Early Developmental Census (AEDC) (n = 173,200) and defined as scoring <10th percentile in ≥2/5 developmental domains (physical health and wellbeing, social competence, emotional maturity, language and cognitive skills, communication skills, and general knowledge). The second, educational outcome at age 7 to 9, was assessed using National Assessment Program–Literacy and Numeracy (NAPLAN) data (n = 342,311) and defined by overall z-score across 5 domains (grammar and punctuation, reading, writing, spelling, and numeracy). Inverse probability weighting with regression adjustment was used to estimate population average causal effects.
The study included 412,713 children across the 2 outcome cohorts. Linked records were available for 4,697 IVF-conceived cases and 168,503 controls for AEDC, and 8,976 cases and 333,335 controls for NAPLAN. There was no causal effect of IVF-conception on the risk of developmental vulnerability at school-entry compared with spontaneously conceived children (AEDC metrics), with an adjusted risk difference of −0.3% (95% CI −3.7% to 3.1%) and an adjusted risk ratio of 0.97 (95% CI 0.77 to 1.25). At age 7 to 9 years, there was no causal effect of IVF-conception on the NAPLAN overall z-score, with an adjusted mean difference of 0.030 (95% CI −0.018 to 0.077) between IVF- and spontaneously conceived children. The models were adjusted for sex at birth, age at assessment, language background other than English, socioeconomic status, maternal age, parity, and education. Study limitations included the use of observational data, the potential for unmeasured confounding, the presence of missing data, and the necessary restriction of the cohort to children attending school.
Conclusions
In this analysis, under the given causal assumptions, the school-age developmental and educational outcomes for children conceived by IVF are equivalent to those of spontaneously conceived children. These findings provide important reassurance for current and prospective parents and for clinicians.
Medscape article – IVF-Conceived Children Show Strong Developmental Performance (Open access)
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