but medically, it's not advisable.

A quick Google brings this up straight away:
The risks associated with being over 35 and pregnant tend to be exaggerated. If you're in this age group, and are healthy, you can generally expect to have a successful pregnancy, so try not to worry.
In addition to this, medical professionals are aware of the risks and they are therefore managed. For example, screening tests, checks on the wellbeing of the mother and the baby, managed delivery if need be, and so on. Where I live, higher risk mothers (including those at higher risk due to age) have a consultant appointment at 12wks to plan what care they'll need. Some of them won't need to see the consultant again, some of them will need to be seen again, and usually a scan is offered at around 34wks to check all is well.
Statistically, even when you're 35 and therefore old and decrepit, you are still far more likely to have a healthy pregnancy and a healthy baby than not.