9 October 2020

More bronchitis, allergies in donor-conceived adults

Allergies Asthma Genetics

Higher rates of environmental allergies and acute bronchitis have been reported by adults conceived with donor sperm in an Australian study, though there was no difference in most physical health outcomes.

More than 270 adults conceived with donor sperm, aged 18 years or older, were surveyed in a recent study about their physical health, along with 870 naturally conceived people from Australia, the US, UK, Belgium and 32 other countries.

It is well known that people conceived by IVF and other assisted reproductive technologies (ART) have poorer health outcomes at birth: more likely to be born early and with low birth weight. Using donated eggs and sperm can also vary that risk.

But with the scarcity of data on the long-term health outcomes among people born by assisted reproduction and more specifically, donor sperm, it remains unclear whether poor health outcomes associated with ART at birth extend into adulthood.

“Many of these perinatal complications associated with ART may be markers of disturbed early development, which could predispose to chronic disease risk in later life,” said Dr Michele Hansen, an epidemiologist at Telethon Kids Institute in Perth studying health outcomes in ART conceived children.

The study, conducted by researchers at Flinders University in Adelaide and published in the Journal of Developmental Origins of Health and Disease, is the first to examine physical health outcomes in adults conceived with donated sperm. This subset of the ART community has been difficult to reach because non-disclosure was the norm when they were conceived.

Participants were recruited via support groups for the donor-conceived community and social media, and asked to report on physical health conditions for which they had been diagnosed by a doctor. No clinical assessments were involved.

For most of the roughly 100 health outcomes, no difference was found between the two groups.

However, adults conceived with donor sperm reported a higher incidence of acute bronchitis than those conceived naturally (22.4% compared to 13.2%), but no differences were observed for other respiratory conditions, such as asthma and COPD.

The donor-conceived group also had almost double the reported incidence of environmental allergies (29.4%) compared to adults conceived naturally (16.7%), but food and medication allergies were no different.

In the process of assisted reproduction, the authors wrote, donor sperm and eggs would be frozen, handled and manipulated, which could damage DNA. But it was difficult to disentangle the effect of this from other factors simultaneously affecting the child’s health, such as the parents’ underlying subfertility or pre-existing medical conditions.

Pregnancies conceived using donated sperm (or eggs) are associated with a higher risk of pre-eclampsia, which has been linked to a range of adverse perinatal and later health outcomes, including cardiovascular disease in adulthood, Dr Hansen said. ART-conceived pregnancies are also more likely to be delivered by caesarean section, which may be associated with higher rates of asthma.

The study did not report on the participants’ perinatal health outcomes, method of delivery or if their mothers had specifically experienced pre-eclampsia during pregnancy.

Dr Hansen also noted that donor-conceived people who responded to the survey might have had poorer health and been concerned about potential reasons why, introducing self-selection bias.

Nevertheless, “Adults conceived using donor sperm were not at an increased risk of any of the conditions that have been associated with poor perinatal outcomes, such as cardiovascular disease, type II diabetes and obesity,” said Dr Hansen, who was not involved in the study. “And they were not more likely to have asthma, nasal allergies or hay fever.”

“Overall, there was not a lot of difference between these two groups.”

When the analysis was restricted to just Australian-born participants, the largest country of birth cohort in the study, there was no difference in any physical health outcomes.

Dr Hansen noted some limitations. The adults recruited to the study had an average age of 33 ­– probably too young to allow adequate assessment of some chronic diseases that develop in later life.

Secondly, the group of naturally conceived adults might not have been an ideal comparison sample. The group appeared to be healthier than the general population when compared to reference data from the ABS and US CDC (national datasets that include more people under 18, and more older, poorer people, respectively).

As for assessing the risk of asthma, results from others studies of people born by ART have been mixed. Studies from the UK and Australia have previously reported slightly higher rates of asthma among children and young adults conceived by ART.

But a 2019 study of Victorian adults, aged 22-35 years old, conceived by ART found no evidence of respiratory problems in the group, compared to other Victorians conceived naturally.

Although the ART-conceived adults in the Victorian study did self-report a higher prevalence of ever having asthma, on physical assessment their rates of asthma were much the same as their naturally conceived peers, leading the authors to conclude that any risk of asthma could be age-dependent and might not persist into chronic adult asthma.

J Dev Orig Health Dis 2020, 28 Aug

 

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