More children hitting puberty too soon, say NUH doctors
Published on 4 November 2025
Cases of early puberty have quadrupled at NUH over the past decade, with doctors studying possible lifestyle and environmental causes.
At a glance
- Early puberty cases at NUH have quadrupled, from 35 in 2014 to 143 in 2024.
- Puberty before age 8 in girls or age 9 in boys is considered early.
- Often has no clear cause, but may be linked to diet, sleep or environmental chemicals.
A growing concern among parents
Parents are noticing something unusual – children showing signs of puberty years earlier than expected.
At the National University Hospital (NUH), specialists say they are seeing a sharp rise in such cases and are investigating possible triggers.
At NUH’s paediatric endocrine clinics, new cases rose from 35 in 2014 to 143 in 2024 – a fourfold increase in 10 years.
While these figures reflect one hospital’s own caseload rather than national data, doctors say the pattern is consistent with global observations, especially since the COVID-19 pandemic.
Dr Yvonne Lim, Senior Consultant at the Division of Paediatric Endocrinology, Department of Paediatrics, Khoo Teck Puat – National University Children’s Medical Institute (KTP-NUCMI), NUH, said more parents have noticed children maturing earlier.
“Some are as young as Primary 4,” she said. “The trend mirrors what is being reported in other developed countries.”
Why early puberty matters
Early puberty can have long-term consequences beyond physical change.
“One major concern is compromised final adult height, because early puberty shortens the growth window,” said Dr Lim.
Girls may also begin menstruating before they are emotionally ready to manage it. Research has linked early puberty in girls to higher risks of obesity, cardiovascular disease and breast cancer later in life. It can also affect mental health.
“Girls who develop early can feel self-conscious or experience low mood,” Dr Lim added.
When is puberty considered too early?
Doctors say puberty is considered unusually early when it starts before age eight in girls or nine in boys.
In medical terms, precocious puberty refers to the onset of breast or pubic hair development before eight years old in girls, or testicular enlargement (measuring about 4ml with an orchidometer) or pubic hair before nine years old in boys. For girls, getting their first period before 10 is also regarded as early.
Treatment depends on how early puberty begins and how fast it progresses. At NUH, doctors may prescribe GnRH-analogue injections to temporarily block puberty. Given every 12 weeks, the medication halts hormonal changes until a more appropriate age. Some families, however, choose to monitor their child without intervention.
“What matters,” said Dr Lim, “is regular medical follow-up and open communication with doctors.”
Dr Lim recalled two contrasting cases. One was a 15-month-old girl who developed breasts and even began menstruating. Scans revealed a hypothalamic hamartoma, a small congenital brain tumour that triggered central precocious puberty. She remains on treatment.
Another case involved a seven-and-a-half-year-old girl who developed breasts but had no identifiable cause.
“More than 95 per cent of girls seen at NUH have idiopathic precocious puberty – cases where no underlying disease is found,” Dr Lim said.
The child was started on a pubertal blocker to pause further development until an appropriate age.
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Parents should seek medical advice if they notice:
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What could be causing it
Only a small number of cases are due to brain or ovarian abnormalities. Most are idiopathic, thought to result from a mix of genetic and environmental influences.
“These can include endocrine-disrupting chemicals – substances in the environment such as air, soil or water supply – food, personal care products and manufactured products that interfere with the normal function of your body’s endocrine system,” said Dr Lim.
Studies have examined compounds such as musk ambrette (a perfume ingredient) and phthalates, chemicals found in plastics and some processed foods.
Lifestyle factors may also play a role. Research has linked frequent intake of fried foods and snacks, sleeping with lights on, high poultry consumption and early exposure to sexualised media with earlier puberty onset.
“High vegetable and protein dietary patterns appear to be protective, while diets high in animal foods and fruits correlate with earlier puberty in some studies,” Dr Lim said.
However, she cautioned that evidence linking specific foods, such as frozen chicken raised with growth hormones, remains inconclusive.
“The role of diet in precocious puberty is still being studied,” she said.
What parents can do
- Watch for early changes. Seek medical advice if girls show breast buds before 8 or boys show pubic hair or a growth spurt before 9.
- Encourage balanced meals. Focus on fresh, minimally processed foods; eat red meat and eggs in moderation; and increase vegetable intake.
- Reduce chemical exposure. Avoid perfumes or cosmetics for children.
- Promote quality sleep. Let children sleep in the dark, without a night light.
- Keep them active. Daily exercise helps maintain a healthy weight and supports hormonal balance.
If a child begins showing signs of puberty earlier than expected, parents should not panic but seek timely evaluation.
“When puberty starts early but still within the normal range – after eight years old for girls and after nine for boys – treatment may not be needed,” said Dr Lim. “But if parents are keen for an evaluation, they can get a referral to see a paediatric endocrinologist.”
The bigger picture
In consultation with Dr Yvonne Lim, Senior Consultant, Division of Paediatric Endocrinology, Department of Paediatrics, Khoo Teck Puat-National University Children’s Medical Institute, NUH.
