The problem that ART-HEALT is addressing:
Infertility is common. It affects 1 in 6 people who are trying to get pregnant. Assisted reproductive technologies (ART), which include vitro fertilisation (IVF), and intracytoplasmic sperm injection (ICSI), are used to enable pregnancy in those with infertility. ART is increasingly used worldwide,. Since the first ART birth in 1978, research has largely focused on methods to improve live-birth rates, with the result that 25-40% of ART now result in a live-birth. Now-a-days ART is considered to be a routine effective treatment for infertility. With the widespread use of ART, concerns have been raised about its potential effect on future health. Some evidence suggests that that people conceived and born by ART are more likely to be obese and have high blood pressure, cholesterol levels, type 2 diabetes and heart disease.
Why is this important?:
We need to know if ART is causing these health problems and if it is whether there are specific types of ART that cause the problems. For example if some ways of stimulating a woman’s hormones to produce an egg are part of the problem or if any type of ART might cause these problems. If any or some types of ART cause these problems it is then we might be able reduce the problem with existing treatments for e.g. reducing blood pressure.. If, on the other hand we show that ART does not cause theses problems, then we can reassure people considering ART and those who have already been born with it that they are not at increased risk.
It is difficult to determine if ART causes health problems. This is because it is difficult to be able to tell whether an association of ART conception with such problems is because the ART causes these adverse outcomes or because the association is due to bias giving us the wrong answer, or is explained by confounding. Confounding occurs when we assume something is causal but we are in fact being fooled (confounded) into thinking that, by other things that produce the association. For example, most couples who need ART are likely to be infertile, and it might be the cause of their infertility (which is more likely in older people, those who smoke and those who are obese) that causes the offspring obesity ad heart disease than the ART.
Objectives of ART-HEALTH.
Our overall goal is to used state-of-the-art methods to determine whether conception by ART results in increased risk of adverse pregnancy and later life health problems. We are doing this through the following objectives
1. We are brining together three types of studies and applying different novel analysis methods to these different study times. One type of study brings birth cohorts from across the world together. These studies follow people from when they were in the womb during their mothers pregnancy, through birth, childhood and into adulthood. The strengths f this collaboration of birth cohorts is that we do not select on whether someone is conceived by ART or not. This means that those conceived by ART or natural conception are treated the same, with all the same measures on both groups. We can also look at whether any effect of ART changes over time as people get older. : The down side of the birth cohorts they often do not have detailed information on exactly how the ART was done. The second type of study is large electronic health record studies of whole populations. These have the advantages that they are very large, cover the whole population, such as the whole of the UK over many years, and are less likely to suffer from selection bias. They will have more details on the types of ART that were used compared to the birth cohorts. The down side of these is that they have less information on confounders than the birth cohorts. Lastly we are suing data from clinical cohort that has collected very detailed information on the whole ART process on 500 couples and for those who become pregnant comparing their pregnancy health and offspring later life health with a cohort of people from the same city who have the same measures from birth onwards. This will enable us to look at different aspects of the ART treatment, with much more detail than either of the first two. Across all three types of study we will use different types of analyses that have different biases. If se see similar results across the different study types and analysis types this gives us greater confidence that those results are the correct causal answer.
2. We are using the above data and methods to determine the effect of ART on pregnancy health and cardiovascular health.
3. We are using the above data and methods to explore biological mechanisms for any effects on pregnancy and cardiovascular health.
