A quarter to half of all pregnancies end in miscarriage - but usually in the first 12 weeks. After that, mums-to-be hope to be in the safe zone. Each celebrity loss to hit the headlines is a reminder that this is not always the case.
It's particularly devastating as mothers have to go through the trauma of giving birth.
Ruth Bender Atik of The Miscarriage Association stresses that late miscarriages are very unusual, with figures showing only one to two per cent of women lose babies in the second trimester.
'We have what appears to be a cluster of late-term losses, and it's easy to assume this might be a problem, but it's not,' she says.
'It's just awful coincidence that three pregnant celebrities have suffered the same tragedy over such a short period of time.'
While Britain has the third highest rate of stillbirths in developed countries (ranking 33 out of 35), figures for miscarriage are not systematically recorded, according to Ruth.
'But the growing number of older mums is a good reason to assume that miscarriage - at any stage of pregnancy - is on the increase,' she says.
In the past 20 years, the number of new mums over the age of 40 has nearly tripled, from 9,336 in 1989 to 26,976 in 2009.
'Just as older women find it harder to conceive, they will also find it harder to hold on to a pregnancy,' Ruth explains.
Poor-quality eggs can lead to miscarriage at any time in pregnancy, and we now think an older man's sperm also makes a more vulnerable foetus. Chromosomal problems (e.g., Down's syndrome or Edwards syndrome) are also more common in older women, and these make a pregnancy more susceptible to miscarriage.
'Other things that affect your risk of late miscarriage include infections and a weak cervix, while miscarriage at any stage can be triggered by conditions like antiphospholipid syndrome (APS), which makes blood clot too easily, or even stress.
'In a study by The Miscarriage Association, women who were subjected to long-term stress at work were more likely to miscarry. But often there is no known cause.'
'Late miscarriages (at 14-23 weeks) are more likely to be investigated than early ones, because they're far less common and a cause is more likely to be found. But if your miscarriages are all in the first trimester, you may have to suffer three in a row before you and your partner are referred for tests.
'Even then, only half of couples tested will find a cause, and only some of those problems are treatable, such as APS,' says Ruth.