Caesarean births, common in Hong Kong, linked to higher childhood obesity risk

Also in health news: a smartphone app aims to prove the link between weather conditions and chronic pain; and achieving recommended weekly amount of exercise may stave off alcohol-related disease

PUBLISHED : Thursday, 08 September, 2016, 8:05pm
UPDATED : Thursday, 08 September, 2016, 8:05pm

Children born by caesarean appear to be at a higher risk of becoming obese, especially when compared to their siblings born via vaginal birth, according to recent research by the Harvard T.H. Chan School of Public Health in Boston. This finding has particular significance for Hong Kong, which has one of the highest rates of caesarean delivery in the world.

Caesarean sections should only be performed out of medical necessity, World Health Organisation warns

In the study, which appears online in JAMA Pediatrics, 22,068 children born to 15,271 women were followed up until early adulthood through questionnaires. Among the children studied, 4,921 were born by caesarean delivery. Women who had caesarean delivery had a higher BMI before pregnancy and were more likely to have gestational diabetes, pre-eclampsia and pregnancy-induced high blood pressure.

Compared with vaginal birth, caesarean delivery was associated with a 15 per cent increase in the risk of obesity in children after adjusting for mitigating factors, the study found. Within families, children born by caesarean were 64 per cent more likely to be obese than their siblings born by vaginal delivery.

Children born by vaginal birth to women who had had a previous caesarean delivery were 31 per cent less likely to be obese compared with those children born to women with repeated caesarean deliveries.

Hong Kong study seeks to quell fears over condition that leads many to seek caesareans

The study suggests a higher risk of obesity for children associated with caesarean birth may be related to differences in the gastrointestinal microbiota established at birth. Babies born vaginally have greater exposure to their mother’s vaginal and gastrointestinal microbiota.

“These findings suggest that this association may be a true adverse outcome of caesarean delivery that clinicians and patients should weigh up when considering caesarean birth in the absence of a clear medical or obstetric indication,” say the authors.

Nearly one in two Chinese mothers chose to give birth by caesarean

The researchers identified limitations to the study, which include a lack of data on indications for caesarean delivery or other detailed data on aspects of labour and delivery.

Link between weather and chronic pain is emerging through innovative smartphone research

Some people claim the onset of aches and pains means it’s going to rain. There seems to be some truth to it: preliminary findings from a mass participation study in the UK have indicated a link between weather conditions – specifically rain and lack of sunshine – and chronic pain.

At the halfway stage of the 18-month-study “Cloudy with a Chance of Pain” led by the University of Manchester, analysis of daily data input from more than 9,000 participants in Leeds, Norwich and London suggests a correlation between the number of sunny days and rainfall levels and changes in pain levels. Across all three cities, as the number of sunny days increased from February to April, the amount of time spent in severe pain decreased. However, the amount of time spent in severe pain increased again in June when the weather was wetter and there were fewer hours of sunshine.

Professor Will Dixon, who leads the study, reported interim findings at the British Science Festival on September 7. He said early results were encouraging but more participants were needed to allow robust conclusions at the end of the study. “Once the link is proven, people will have the confidence to plan their activities in accordance with the weather. In addition, understanding how weather influences pain will allow medical researchers to explore new pain interventions and treatments.”

Members of the public who suffer long-term pain record their daily pain symptoms on a special app. The app also independently captures hourly weather conditions using the smartphone GPS, thus joining pain data with real-time local weather events.

Find out more about the study at

Recommended weekly physical activity level may offset some of alcohol’s lethal harms

If you drink, don’t drive. Better yet, go for a run. Clocking up the recommended weekly amount of physical activity may offset the heightened risks of death from all causes – including cancer – that are associated with drinking alcohol, according to new study published online in the British Journal of Sports Medicine.

The team of researchers from four countries analysed responses to nationally representative health surveys carried out in England and Scotland for the years 1994, 1998, 1999, 2003, 2004 and 2006. These surveys included questions about the frequency and type of alcohol intake and physical activity levels among those aged 40+. The participants were monitored up to the end of 2009 in Scotland and the end of 2011 in England.

After taking account of potentially influential factors, a direct association emerged between drinking alcohol and death from all causes and from cancer. Compared with lifelong abstinence, drinking in the past and drinking at hazardous levels (up to 35 weekly units of alcohol for women and 49 for men) were associated with a clearly defined heightened risk of death from all causes. And the higher the tally of weekly units, the greater the risk of death from cancer, even if total alcohol intake fell within the weekly recommended maximum (a maximum of 14 units for women and 21 for men).

This risk of death was reduced or cancelled out among those who were physically active, from the minimum recommended level upwards, while the association between alcohol and heightened risk of death from all causes was slightly lower up to hazardous drinking.

This is an observational study so no firm conclusions can be drawn about cause and effect, and the researchers acknowledge that they didn’t measure drinking patterns or dietary factors, both of which could have affected the results.