50,000 Chinese Babies to be Recruited for Health Study by 2020
The “Born in Guangzhou Cohort Study” is looking to recruit 50,000 baby-mother sets by 2020. The study so far has recruited around 33,000 babies and their mothers since 2012, collecting biological, environmental and social data. This year, the study has begun to recruit 5,000 maternal grandmothers, too, enabling studies across multiple generations.
Over the six years, an accumulation of over 1.6 million biological samples have been collected, including specimens of stools, blood, placental tissue and umbilical cords. Metadata. Extensive surveys have also recorded participants’ eating habits, mental health, and other lifestyle factors, such as the amount of mould in their house, reports Nature.
“The data is vast, and there is space for many different groups globally to mine this information,” says Maria Gloria Dominguez-Bello, a microbiologist at Rutgers, The State University of New Jersey, in New Brunswick, who is not involved in the study. “I really admire this effort from the Chinese team. Very few countries can achieve this scale.”
The richness of the data and the collection of microbiome data is setting the project apart from previous large birth cohort studies such as those carried out in Norway and Denmark. Two other large birth-cohort studies, in the United States and United Kingdom, had planned to include microbiome data, but both were cancelled because of trouble recruiting participants. The US study also struggled with excessive costs and management issues.
What have they found out so far?
Some of the first results published suggest that exposure to fumes from burning incense increases the risk of hypertension in expectant mothers. Another study found that 40% of pregnant women were prescribed progesterone too early during pregnancy. Progesterone is a drug used around the world to reduce the risk of preterm birth, but when given too early during pregnancy, does not reduce the chance of preterm birth, but instead puts mothers at risk of needing a caesarean section and developing post-partum depression. These findings were considered by the researchers as “an urgent public-health concern.”
Studies in progress
A team from the University of Birmingham in the UK and BGI, one of China’s largest genome-sequencing institutes, in Shenzhen, is currently looking at how the microbiomes of babies differ in babies born through the vagina and those born through caesarean section. Although similar, smaller studies have been done before, Dominguez-Bello says the Guangzhou cohort will offer the statistical power to separate out other variables that could influence an infant’s microbiome. These include pre- and postnatal medications, including antibiotics, and environmental pollutants.
Xiu Qiu, an epidemiologist at Guangzhou Women and Children’s Medical Center and the director of the Guangzhou project, is using the cohort data to test her surprising, but tentative, finding that older mothers having a second child have a lower risk of depression during pregnancy than do women pregnant with their first child. She had expected the opposite to be true because women who already have a baby when they are pregnant would be under more stress and face a higher financial burden, and so would be more depressed. The end of China’s one-child policy in 2016 means the birth-cohort study offers a fresh opportunity to study the mental health of an increasing number of women, many of them older, who are having a second child, she says.
Sing Sing Way, a paediatrician at the Cincinnati Children’s Hospital in Ohio, meanwhile, will be looking at the data provided by the addition of grandmothers to the study to understand why cells from mothers can live on indefinitely in their offspring. Studies in mice suggest that these cells play a protective role when the offspring are pregnant, says Way, who will use the grandmother data to test this hypothesis in people.