Some are experiencing puberty at age six; they are likely to be obese
A TREND that has surfaced in developed countries around the world – more girls reaching puberty at a younger age – is also being seen here, doctors say.
No studies have been done on the phenomenon here, but doctors contacted by The Straits Times say they have noticed an increase in such cases over the past decade.
Most girls reach puberty at the age of 10 or 11, though it is considered normal if this occurs between the ages of eight and 13. However, more girls here are growing breasts and/or pubic hair at age seven.
Associate Professor Lee Yung Seng, a senior consultant in paediatric endocrinology at the National University Hospital (NUH), said the hospital now sees six to eight such cases a month, an increase of about 20 to 30 per cent compared to 10 years ago.
He estimates that the phenomenon occurs in between 3 and 5 per cent of young girls in Singapore.
And while seven is already considered young, KK Women’s and Children’s Hospital (KKH) gets about 100 cases a year where girls six years and younger are experiencing the early onset of puberty, said Associate Professor Fabian Yap, its head of paediatric endocrinology.
The doctors’ experience mirrors the results of a recent study conducted in the United States, which found that girls are more likely today than in the past to start developing breasts by age seven or eight.
American researchers suspect that higher obesity rates are largely responsible. Some also think that environmental chemicals which mimic the effects of oestrogen may be speeding up the clock on puberty, but that link is as yet unproven.
Singapore doctors also see the link between obesity and the early onset of puberty.
Nutrition plays a part in this, theysaid: The body needs a certain amount of fat to reproduce. Once it has enough, it triggers the move towards puberty.
This is possibly why early onset of puberty is more often seen in fat girls.
Dr Vera Oh, a paediatrician at Mount Elizabeth Medical Centre, said more than half of the seven-year-old girls she has seen with early puberty are obese.
The early onset of puberty is of concern for several reasons.
Girls who experience it are likely to grow up shorter, for one, the doctors say. Since they begin their growth spurts at a younger age, they might stop growing by the time they hit 12 or 13, instead of at 16, which is the norm.
Recent reports also said studies suggest that earlier puberty, as measured by the age at first menstruation, can slightly increase the risk of breast cancer, probably because it results in longer lifetime exposure to the hormones oestrogen and progesterone, which can feed some tumours.
Earlier-than-normal puberty also has an emotional impact on girls. Those who experience it are too young to deal with the surge of hormones they experience at that stage of life, and could turn aggressive.
A girl whose mind is not sufficiently developed although her body is might also have trouble fending off unwanted sexual advances.
However, Dr Oh cautioned that not all girls who start showing signs of puberty at an early age would suffer ill-effects.
“Some dawdle along, while others progress at a fast pace,” she said. This is why doctors sometimes monitor the progress of such patients before acting.
Doctors stressed that the most important course of action when encountering early puberty is to rule out sinister reasons, such as a tumour. In boys, early puberty – a rare phenomenon – is usually triggered by a serious illness, such as a brain tumour.
This could be true for some girls too, doctors, said.
There are safe drugs available to delay early puberty, Prof Lee said, but administering them requires monthly injections.
He added that whether to stop the onset of puberty is often merely a matter of preference.
Dr Oh agreed, as the vast majority of girls with early puberty do not face too many problems.
She added that ensuring that children are not obese could help, and is certainly better for their health generally.