Like thousands of twins each year, many triplets are born to mothers who have delayed having children until they are older and less fertile. They then need help in becoming pregnant, and are given ovulation-inducing drugs or IVF treatment, which can lead to multiple births. Last year some 300 sets of triplets were born in Britain and 8,749 sets of twins - an enormous financial, physical and emotional strain on their families.
The cost of baby clothes and equipment, the sleepless nights and the juggling required to deal with two or three children at once is considerable.
There is also concern among doctors that use of the drugs, which do not come under the auspices of the Human Fertilisation and Embryology Act, is not being monitored properly.
For Shree Merriman, 37, and her husband Brendan, from East Molesey, Surrey, the triplets, born after a fifth and final attempt at IVF, were everything they wanted.
Mrs Merriman said: "I am not able to have children naturally and we have been trying for over seven years. The only course open was IVF.
"When this attempt was successful I was originally meant to have two babies, but two became three when one of the eggs split. I now have identical girls and one boy, all born 10 weeks premature.
"We knew they were triplets about eight weeks into the pregnancy, when the hospital did a scan. It was a surprise, but we were pleased and happy and grateful to King's College Hospital because we had waited for so long and tried so hard."
The financial costs of triplets for the Merrimans is high. Equipment alone is likely to cost around pounds 3,000. Estimates for the annual bill run to about pounds 9,000.
Dr Carol Cooper, author of Twins and Multiple Births, herself the mother of 10-year-old twins, says that mothers of triplets need to spend up to 197.5 hours a week on baby care and household chores. "Since there are only 168 hours in a week, extra help has to be enlisted and funded," she says. "Then there is the possible loss of one income and often the need for a larger home, at a time when finances are very tight."
Breast feeding can be difficult, shopping or visiting friends with a triple-seater buggy is a nightmare, and sleeping through the night is a distant memory.
Dr Cooper warns that the perinatal death rate among twins is five times higher than in singletons and that cerebral palsy is more common.
She says there is a strong argument for better controls over ovulation- inducing drugs.
"Although it is a much quicker way of achieving a pregnancy than waiting for a specialist clinic, it is becoming clear that induced ovulation with drugs can do women a disservice unless carefully monitored.
"A woman may not know until it is too late that she had produced two, three or even more eggs in one cycle instead of the required one. There must be a strong argument for controlling the use of ovulation induction."
Tamba, the Twins and Multiple Birth Foundation, has a helpline: 0151- 348 0020.Reuse content