Link between parental infertility and risk of autism in children

Summary: A study of 1.3 million children found that children born to parents with fertility problems have a slightly higher risk of autism spectrum disorder (ASD). Research suggests that the risk of ASD is increased in children whose parents have already been diagnosed with infertility, regardless of whether fertility treatments were involved.

The study also highlights the role of obstetric factors such as multiple pregnancies and premature births in mediating this association. Further research is needed to explore the mechanisms behind this link.

Highlights:

1. Children born to parents with infertility problems have a slightly elevated risk of developing autism spectrum disorder (ASD).
2. This increased risk is independent of whether fertility treatments were used or not.
3. Obstetric factors, such as having twins or premature birth, mediate a large extent in the association between parental infertility and ASD.

Source: Queen’s University

One in 50 Canadian children suffer from autism spectrum disorder (ASD), a neurodevelopmental condition that can impact sensory processing, communication, and emotional and behavioral regulation. Yet the causes of this lifelong disorder remain unclear and likely include a combination of genetic and environmental factors.

A new study published today in Open JAMA Network reports on a cohort study of more than 1.3 million children born in Ontario between 2006 and 2018. Results suggest that children born to people diagnosed with fertility problems are at slightly higher risk of TSA.

As infertility diagnoses increase – an estimated one in six couples face this challenge – publicly funded fertility programs have also increased access to fertility treatments in Canada. Along with this growth, there is a need to answer questions about the health outcomes of mothers and children who receive fertility treatment.

The recently published study, led by Maria Velez (obstetrics and gynecology), evaluated pregnancy and infant characteristics in relation to infertility, its treatments, and ASD using existing linked health administrative data .

Children were classified by mode of conception, namely unassisted conception (86.5 percent), infertility without fertility treatment or subfertility (10.3 percent), ovulation induction or l intrauterine insemination (1.5 percent) and in vitro fertilization or intracytoplasmic sperm injection (1.7 percent). .

Starting at 18 months, children were followed for a period of 5 to 11 years, and 22,409 children were diagnosed with ASD, or 1.6% of the total. Because not all children were followed for the same time period, the ASD incidence rate was calculated in person-years – a type of measure that takes into account both the number of people participating in the study and the time each person devotes to it.

For example, a study that follows 1,000 people for a year each would contain 1,000 person-years of data.

In this study, the incidence rate of ASD was 1.9 per 1,000 person-years in children in the first group, and higher in children in the subfertility groups (2.5) and after fertility treatment (2.7).

The results suggest that there is a slightly increased risk of ASD in children born to patients previously diagnosed with infertility, whether or not they received fertility treatment.

“In addition, our results also show that certain obstetric factors, such as having twins or triplets, or giving birth prematurely, mediate a large part of the association between parental infertility and ASD,” explains Dr. Velez.

According to the authors, the findings support continued ongoing efforts to minimize the risks of multiple pregnancy and premature birth following fertility treatments, as well as the importance of providing early care plans to pregnant patients who have received such treatments, with the aim of reducing unwanted pregnancies. results in this population.

Additional studies are needed to understand some of the mechanisms by which a parental diagnosis of infertility, independent of fertility treatment, may be associated with a slightly higher risk of ASD in the child.

“For example, we need more precise details on the basic infertility diagnosis, paternal factors and whether the oocyte (egg) or sperm comes from the parent or a donor, among other factors,” explains the Dr. Velez.

About this autism research news

Author: Catarina Chagas
Source: Queen’s University
Contact: Catarina Chagas – Queen’s University
Picture: Image is credited to Neuroscience News

Original research: Free access.
“Infertility and risk of autism spectrum disorders in children” by Maria Velez et al. Open JAMA Network

Abstract

Infertility and risk of autism spectrum disorders in children

Importance

Previous studies on the risk of childhood autism spectrum disorder (ASD) after fertility treatment did not take into account infertility itself or the mediating effect of obstetric and neonatal factors.

Objective

To evaluate the association between infertility and its treatments on the risk of ASD and the mediating effect of certain adverse pregnancy outcomes on this association.

Design, setting and participants

This was a population-based cohort study conducted in Ontario, Canada. Participants were all singleton and multifetal live births at 24 weeks gestation or greater between 2006 and 2018. Data were analyzed from October 2022 to October 2023.

Exhibitions

The exhibition was about the mode of conception, namely (1) unassisted conception, (2) infertility without fertility treatment (i.e. subfertility), (3) induction of ovulation (OI) or intrauterine insemination (IUI) or (4) in vitro fertilization. (IVF) or intracytoplasmic sperm injection (ICSI).

Main results and measures

The study outcome was a diagnosis of ASD at age 18 months or older. Cox regression models generated hazard ratios (HRs) adjusted for maternal and child characteristics. The mediation analysis further considered the separate effects of (1) preeclampsia, (2) cesarean section, (3) multifetal pregnancy, (4) preterm delivery at less than 37 weeks, and (5 ) severe neonatal morbidity.

Results

In total, 1,370,152 children (703,407 boys (51.3%)) were included: 1,185,024 (86.5%) with unassisted conception, 141,180 (10.3%) with parental subfertility, 20,429 (1.5%) following an IO or IUI. , and 23,519 (1.7%) after IVF or ICSI. People who underwent treatment for subfertility or fertility were older and resided in higher-income areas; the mean (SD) age of each group was as follows: 30.1 (5.2) years in the unassisted conception group, 33.3 (4.7) years in the subfertility group, 33.1 (4.4) years in the OI or IUI group and 35.8 (4.9) years. ) years in the IVF or ICSI group.

The incidence rate of ASD was 1.93 per 1,000 person-years among children in the unassisted conception group. Compared to the latter, the adjusted HR for ASD was 1.20 (95% CI, 1.15-1.25) in the subfertility group, 1.21 (95% CI, 1 .09-1.34) after IO or IUI, and 1.16 (95% CI, 1.04-1.28) after IVF or ICSI. Obstetric and neonatal factors appear to play a significant mediating role in the aforementioned association between mode of conception and ASD risk. For example, after IVF or ICSI, the proportion of cesarean deliveries was 29%, multifetal pregnancies 78%, premature deliveries 50% and severe neonatal morbidity 25%.

Conclusions and relevance

In this cohort study, a slightly higher risk of ASD was observed in children born to infertile individuals, which appears to be partly due to certain obstetric and neonatal factors. To optimize child neurodevelopment, strategies should further explore these other factors in people suffering from infertility, even among those not receiving fertility treatment.