Tag: premature delivery

Categories : Environmental Effects Obstetrics & GynaecologyTags :

Excess Heat Linked to Preterm Delivery in Study of over a Million Births

On By ModernMedia
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As global temperatures continue to rise, a new study of 1.2 million births in Sydney over two decades has shown a strong association between the risk of pre-term birth and exposure to extreme hot temperatures in the third trimester of pregnancy. The data suggested that this association with extreme temperature might be reduced by greenery.

The findings suggest health services should consider preparing for an increase in preterm births as our climate warms.

The Monash University-led study, published in JAMA Pediatrics, looked at the relationship between preterm birth, exposure to high temperatures as well as the mitigating factor of exposure to trees and overall greenness. Excess heat was defined as trimester temperatures higher than the 95th percentile of trimester distributions over the 20-year period.

The study, led by A/Prof Shanshan (Shandy) Li from the Monash School of Public Health and Preventive Medicine, looked at 1.2 million births – including 63 144 preterm births – occurring in Sydney, between 2000 and 2020, using the New South Wales Midwives Data Collection.

The research team cross-referenced this data with historical temperature data, as well as tree cover and overall greenness levels derived from satellite images.

The research concluded that exposure to both daytime and night-time extreme heat in the third trimester was strongly associated with increased preterm birth risks, unlike the same exposure in either the first or second trimesters.

This association existed for all levels of area-level greenness, although the strength of the association was slightly diminished for women living in areas with more trees and other greenery, raising the intriguing possibility that greenness might ameliorate some of the excess risk from extreme heat exposure in the third trimester that deserves further study.

First author A/Prof Li is an expert in environmental impacts on children’s health.

She says, “The presence of greenery, especially trees, has the potential to mitigate heat levels and lower the risks of preterm birth associated with heat. Greenery also has positive physical and mental health impacts beyond just pregnancy and birth outcomes. We should be integrating heat mitigation strategies such as increasing green spaces into urban planning, to improve public health.”

According to Professor Yuming Guo, senior author on the study, and also from Monash University, there has been increasing but still limited epidemiological evidence linking prenatal environmental temperatures with birth outcomes.

“Emerging evidence suggests that night-time air temperature, particularly extreme night-time heat, significantly impacts health, including sleep and rest. Sleep quality and duration affects various aspects of health, and disturbances in these factors may have consequences for pregnancy outcomes,” he said.

“High night-time temperatures can disrupt circadian rhythms and potentially influence blood pressure, which may be an issue for pregnant individuals. Given the projected increase in extreme temperatures as our planet warms, understanding its impacts on birth outcomes and developing strategies to mitigate the risks becomes crucial.”

Source: Monash University

Categories : Lab Tests and Imaging Obstetrics & GynaecologyTags :

New Ultrasound Method can Predict Risk of Preterm Delivery

On By ModernMedia
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Researchers have developed a way to use ultrasound to estimate the risk of delivering a baby preterm. The new method measures microstructural changes in a woman’s cervix using quantitative ultrasound. The method works as early as 23 weeks into a pregnancy, according to the research, which is published in the American Journal of Obstetrics & Gynecology Maternal Fetal Medicine.

The current method for assessing a woman’s risk of preterm birth is based solely on whether she has previously given birth prematurely. This means there has been no way to assess risk in a first-time pregnancy.

“Today, clinicians wait for signs and symptoms of a preterm birth,” such as a ruptured membrane, explained lead author Barbara McFarlin, a professor emeritus of nursing at University of Illinois Chicago.

“Our technique would be helpful in making decisions based on the tissue and not just on symptoms.”

The new method is the result of more than 20 years of collaboration between researchers in nursing and engineering at UIC and University of Illinois Urbana-Champaign. In a study of 429 women who gave birth without induction at the University of Illinois Hospital, the new method was effective at predicting the risk of preterm births during first-time pregnancies.

And for women who were having a subsequent pregnancy, combing the data from quantitative ultrasound with the woman’s delivery history was more effective at assessing risk than just using her history.

The new approach differs from a traditional ultrasound where a picture is produced from the data received.

In quantitative ultrasound, a traditional ultrasound is performed but the radio frequency data itself is read and analysed to determine tissue characteristics.

The study is the culmination of a research partnership that began in 2001 when McFarlin was a nursing PhD student at UIC. Having previously worked as a nurse midwife and sonographer, she had noticed that there were differences in the appearance of the cervix in women who went on to deliver preterm.

She was interested in quantifying this and discovered that “no one was looking at it.”

She was put in touch with Bill O’Brien, a UIUC professor of electrical and computer engineering, who was studying ways to use quantitative ultrasound data in health research.

Together, over the past 22 years, they established that quantitative ultrasound could detect changes in the cervix and, as McFarlin had suspected long ago, that those changes help predict the risk of preterm delivery.

The preterm birth rate hovers around 10-15% of pregnancies, O’Brien said.

“That’s a very, very high percentage to not know what is happening,” he said.

If a clinician could know at 23 weeks that there was a risk of preterm birth, they would likely conduct extra appointments to keep an eye on the foetus, the researchers said.

But since there had previously been no routine way to assess preterm birth risk this early, there have been no studies to show what sort of interventions would be helpful in delaying labour.

This study, O’Brien explains, will allow other researchers to “start studying processes by which you might be able to prevent or delay preterm birth.”

Source: University of Illinois Chicago