Dr. Rhona Mahony:

I would make one brief comment relating to the 12 weeks and miscarriage. The first trimester, the first 14 weeks of pregnancy, is when the risk of miscarriage is highest. It is about one in five pregnancies and the vast majority of those cases, about 80% or 85%, are related to chromosomal abnormality. Miscarriage is much less common in the second trimester, which is between 14 weeks and 24 weeks, but we can have issues like antiphospholipid syndrome or sticky blood syndromes, infection and cervical incompetence, but it is much rarer. Stillbirth after 24 weeks is very rare. We are looking at instances of about two to three per 1,000. The 12 week issue comes from the fact that at least one in five pregnancies will end in miscarriage in the first trimester.