Autism spectrum disorders in IVF children: a national case-control study in Finland.
Department of Child Psychiatry, University of Turku, Itäinen Pitkäkatu 1/Varia, Turku 20014, Finland.
Does IVF increase the risk of autism spectrum disorders (ASDs)?
No association between IVF and ASDs or any of its subtypes was found in this sample.
WHAT IS KNOWN ALREADY:
Certain prenatal factors may increase the risk of ASDs. Studies on the association between IVF and ASDs have shown inconsistent results. IVF is known to increase the risk of perinatal problems but many of them are related to multiple pregnancies.
STUDY DESIGN, SIZE, DURATION:
This case-control study included 4164 autistic cases and 16 582 matched controls born in Finland in 1991-2005. The cases were diagnosed with ASDs by the year 2007. The maximum age at diagnosis was 16 years.
PARTICIPANTS/MATERIALS, SETTING, METHODS:
Four controls were matched to each case. For singletons the matching criteria were date of birth, place of birth, sex and residency in Finland. For twins the birth order within a twin pair was included as well. In the whole sample, there were 63 cases (1.51%) and 229 controls (1.38%) born after IVF.
MAIN RESULTS AND THE ROLE OF CHANCE:
No significant association was found between IVF and ASDs (adjusted odds ratio (OR):0.9, 95% confidence interval (CI): 0.7-1.3) or
its subtypes childhood autism (OR: 0.8, 95% CI: 0.4-1.5),
Asperger’s syndrome (OR: 0.9, 95% CI: 0.5-1.6) or
other pervasive developmental disorder (OR: 1.0, 95% CI: 0.6-1.6).
When only singletons were included, there was an association between IVF and Asperger’s syndrome in an unadjusted analysis (OR: 2.0, 95% CI: 1.1-3.5) but this was not significant when adjusted for mother’s socioeconomic status or parity.
When the analyses were conducted separately for boys and girls, there was a significant association between IVF and Asperger’s syndrome for boys in an unadjusted analysis (OR: 2.1, 95% CI: 1.2-3.7) but this was not significant in the final adjusted model.
LIMITATIONS, REASONS FOR CAUTION:
Information both on IVF and on ASDs was based on registers and it is possible that there is some misclassification. No information on different subtypes of IVF or other assisted reproduction techniques was available. Statistical power may have been insufficient.
WIDER IMPLICATIONS OF THE FINDINGS:
This study showed no increased risk of ASDs in children born after IVF but studies with larger sample sizes and information on different subtypes of IVF are needed to confirm the finding.
STUDY FUNDING/COMPETING INTEREST(S):
The study was supported by Autism Speaks, NIMH 1K02-MH65422 and NIEHS 1R01ES019004. There are no competing interests.
Further Readings of Interest
Fertility and Autism
A study presented Wednesday at the International Meeting for Autism Research in Philadelphia provides some of strongest evidence to date that Landes might be onto something. The study, conducted by a team at the Harvard School of Public Health, found that autism was nearly twice as common among the children of women who were treated with the ovulation-inducing drug Clomid and other similar drugs than women who did not suffer from infertility, and the link persisted even after researchers accounted for the women’s age.
Moreover, the association between fertility drugs and autism appeared to strengthen with exposure: the longer women reported being treated for infertility, the higher the chances their child had an autism spectrum disorder (ASD
Read more: http://www.time.com/time/health/article/0,8599,1990567,00.html#ixzz2HQeQAxIR
Cerebral palsy, autism spectrum disorders, and developmental delay in children born after assisted conception: a systematic review and meta-analysis.
Nine CP studies showed that children born after IVF had an increased risk of CP associated with preterm delivery. In our meta-analysis including 19 462 children exposed to IVF, we estimated a crude odds ratio of 2.18 (95% confidence interval, 1.71-2.77). Eight ASD studies and 30 studies on developmental delay showed inconsistent results. No studies assessed the risk of CP, ASD, or developmental delay in children born after ovulation induction exclusively.
Methodological problems were revealed in the identified studies, and the gaps in our knowledge about the long-term outcomes of children born after assisted conception are considerable, including a lack of information on the long-term consequences of ovulation induction. Possible associations with ASD and developmental delay need assessment in larger studies. Studies on assisted conception and CP from countries outside of Scandinavia are needed, including detailed information on time to pregnancy, underlying cause of infertility, and type of IVF treatment.