Health of children born to subfertile couples: aetiological pathways and neurodevelopmental correlates

More than 1 out of 10 couples is confronted with fertility problems: they fail to conceive within one year. The number of couples seeking medical help to conceive is increasing; already over 5 million children have been born following in vitro fertilisation (IVF, also known as ‘test-tube conception’). It is therefore of utmost importance to examine whether IVF children are just as healthy as children born to fertile parents and children born to parents that also had fertility problems but eventually conceived naturally. This thesis studied the effects of the hormones used in IVF, the laboratory procedures and the underlying fertility problems of the parents on the health of the resulting offspring. We demonstrated that it is not the IVF-treatment, but the underlying fertility problems of the parents that increase the risk for birth defects, worse outcomes around birth (such as a lower birthweight) and a suboptimal neurological development at the age of 2 years. This is reassuring for couples who underwent, or who will undergo IVF-treatment. In addition, we demonstrated that preimplantation genetic screening (PGS), a procedure that was applied to screen embryo’s for chromosome abnormalities, did not affect blood pressure levels in the offspring. The results, however, also suggested that the use of hormones in IVF-treatments may slightly increase blood pressure levels in 4-year-old children. It is therefore important to closely monitor blood pressure in IVF offspring, especially as differences in blood pressure may become more pronounced when the children grow older.