Ten years ago the odds against multiple births were still much the same, but they began shrinking in 1985 and by 1995 the odds had fallen to only 75-1 and are still declining.
No one quite knows why. From a position of complete scientific ignorance I blame the hormones in battery chickens.
More prosaically, the Twins and Multiple Births Association (Tamba) thinks it might be partly due to infertility treatments. A trend towards older mothers may also play a part because the "risk" of twins peaks in the mother's late thirties and recedes again after 40.
Whatever the reason, in 1994 there were 745,000 maternities in the UK, of which 9,518 produced twins, 282 triplets and nine quads.
The incidence was 13.17 per 1,000 maternities in the UK as a whole and 13.22 in England and Wales, compared with 10.10 in 1984. There are marginally more multiple births in England and Wales than Scotland and Northern Ireland.
"On the whole parents don't plan to have twins. The arrival of an instant family means instant expense - double the joys, but double the cost too," says Tamba.
There was a time when quads and even triplets would be showered with manufacturers' gifts, from baby milk to prams, but that also seems to have gone out of fashion.
The increase in the number of multiple births, partly a consequence of infertility treatment, is the most likely cause. It certainly seems as if the public's interest in the subject has waned. Perhaps octuplets or nonuplets would help to revive it.
Insuring against multiple births is not new, but the growing possibility of having a multiple birth might well revive interest in insuring against the event. Eagle Star has brought back a policy to meet demand.
A typical premium for a mother aged 24 to 29 with no twins in the family would be a one-off pounds 41 for a pay-out of pounds 1,000. If there is a history of twins in the mother's family the premium rises to pounds 58 and with twins even on the father's side it is pounds 51.
If the mother is 30 the basic premium with no history of multiple births rises to pounds 45. At 35 it rises to pounds 57 and at 40 it dips to pounds 50. The maximum benefit is pounds 3,000. The policy has to be in place by the 11th week of pregnancy and before any scan is done.
Parents subject to fertility treatment are excluded. Payouts are doubled if triplets or quads are born, although it does not take an Einstein to work out that the extra money will be swallowed up just as quickly by the extra cost of nappies, clothes and baby foods.
As for the amount paid out, it is hardly likely to make anything but the smallest dent in the cost of bringing up a single child, never mind twins or triplets.Reuse content