Meeting NewsPerspective

Fetal overgrowth present weeks before gestational diabetes diagnosis

Ultrasound measurements suggest that fetal abdominal overgrowth is present weeks before pregnant women receive a diagnosis of gestational diabetes, according to study data presented at the European Association for the Study of Diabetes annual meeting.

Yoo-Lee Kim

“We previously reported that fetal abdominal overgrowth was detected at the time of a gestational diabetes diagnosis at 24 to 28 weeks’ gestation, especially among older women or women with obesity, and was persistent until delivery despite appropriate gestational diabetes management,” Yoo-Lee Kim, MD, PhD, professor in the department of endocrinology and metabolism at CHA Gangnam Medical Center and CHA University in Seoul, South Korea, told Endocrine Today. “In this study, we investigated whether fetal abdominal overgrowth is already present at 20 to 24 weeks’ gestation, more than 4 weeks earlier than the time of gestational diabetes screening and diagnosis.”

Kim and colleagues analyzed data from 7,820 pregnant women with (n = 384) and without gestational diabetes (n = 6,919) attending the outpatient clinic of CHA Gangnam Medical Center in Seoul, South Korea. Researchers used ultrasound to measure fetal abdominal circumference, head size and femur length at least 4 weeks before screening for gestational diabetes (mean, 22 weeks’ gestation; 7,297 scans), at the same time as the screening test (mean, 26 weeks; 5,388 scans), and at near term (mean, 35 weeks; 5,404 scans).

At 22 weeks’ gestation, researchers found that abdominal growth of the fetuses of mothers with gestational diabetes was already accelerated compared with fetuses of mothers with normal glucose tolerance, and larger measurements persisted through 35 weeks’ gestation. However, there were no between-group differences in head size or femur length.

Gestational diabetes 2019 
Ultrasound measurements suggest that fetal abdominal overgrowth is present weeks before pregnant women receive a diagnosis of gestational diabetes.
Source: Adobe Stock

“Even among women without diabetes, the babies of mothers who were older or obese were at far greater risk of being abnormally large in abdominal circumference at the 22-week scan, but not in younger and nonobese women,” Kim said. “Overgrowth of the fetal abdomen relative to the head and femur is thought to mean fetal obesity, not simply a big baby.”

Kim said the findings suggest that a current diagnosis of gestational diabetes at 24 to 28 weeks’ gestation and subsequent management are appropriate for women with gestational diabetes who are young and do not have obesity; however, a diagnosis and active intervention for gestational diabetes during early or even before pregnancy might be necessary to prevent fetal obesity, especially among older women or women with excess weight. – by Regina Schaffer

Reference:

Kim YL, et al. Abstract 926. Presented at: European Association for the Study of Diabetes Annual Meeting; Sept. 16-20, 2019; Barcelona, Spain.

Disclosures: The authors report no relevant financial disclosures.

Ultrasound measurements suggest that fetal abdominal overgrowth is present weeks before pregnant women receive a diagnosis of gestational diabetes, according to study data presented at the European Association for the Study of Diabetes annual meeting.

Yoo-Lee Kim

“We previously reported that fetal abdominal overgrowth was detected at the time of a gestational diabetes diagnosis at 24 to 28 weeks’ gestation, especially among older women or women with obesity, and was persistent until delivery despite appropriate gestational diabetes management,” Yoo-Lee Kim, MD, PhD, professor in the department of endocrinology and metabolism at CHA Gangnam Medical Center and CHA University in Seoul, South Korea, told Endocrine Today. “In this study, we investigated whether fetal abdominal overgrowth is already present at 20 to 24 weeks’ gestation, more than 4 weeks earlier than the time of gestational diabetes screening and diagnosis.”

Kim and colleagues analyzed data from 7,820 pregnant women with (n = 384) and without gestational diabetes (n = 6,919) attending the outpatient clinic of CHA Gangnam Medical Center in Seoul, South Korea. Researchers used ultrasound to measure fetal abdominal circumference, head size and femur length at least 4 weeks before screening for gestational diabetes (mean, 22 weeks’ gestation; 7,297 scans), at the same time as the screening test (mean, 26 weeks; 5,388 scans), and at near term (mean, 35 weeks; 5,404 scans).

At 22 weeks’ gestation, researchers found that abdominal growth of the fetuses of mothers with gestational diabetes was already accelerated compared with fetuses of mothers with normal glucose tolerance, and larger measurements persisted through 35 weeks’ gestation. However, there were no between-group differences in head size or femur length.

Gestational diabetes 2019 
Ultrasound measurements suggest that fetal abdominal overgrowth is present weeks before pregnant women receive a diagnosis of gestational diabetes.
Source: Adobe Stock

“Even among women without diabetes, the babies of mothers who were older or obese were at far greater risk of being abnormally large in abdominal circumference at the 22-week scan, but not in younger and nonobese women,” Kim said. “Overgrowth of the fetal abdomen relative to the head and femur is thought to mean fetal obesity, not simply a big baby.”

Kim said the findings suggest that a current diagnosis of gestational diabetes at 24 to 28 weeks’ gestation and subsequent management are appropriate for women with gestational diabetes who are young and do not have obesity; however, a diagnosis and active intervention for gestational diabetes during early or even before pregnancy might be necessary to prevent fetal obesity, especially among older women or women with excess weight. – by Regina Schaffer

Reference:

Kim YL, et al. Abstract 926. Presented at: European Association for the Study of Diabetes Annual Meeting; Sept. 16-20, 2019; Barcelona, Spain.

Disclosures: The authors report no relevant financial disclosures.

    Perspective
    Ravi Retnakaran

    Ravi Retnakaran

    The idea that the metabolic abnormalities associated with gestational diabetes precede the diagnosis is now very much an emerging concept that is recognized in the field. Clinicians can identify women at risk for gestational diabetes in the first trimester and can even identify women at risk before pregnancy. Women at risk for gestational diabetes have metabolic differences when compared with women who do not develop the condition. Secondly, the intrauterine environment in women who develop gestational diabetes has been shown to be different from that of their peers, even prior to the diagnosis of gestational diabetes.

    In that sense, the findings in this abstract and poster very much fit with current thinking. There is one caveat that needs to be recognized with this data: It is often hard to dissect out the contribution of maternal adiposity with respect to any differences observed in fetal growth. If one looks at the four groups stratified by age and prepregnancy BMI, group one — women with gestational diabetes who were lean and young — did not have different fetal abdominal growth measures when compared with women with normal glucose tolerance. Understandably, it would be more difficult to demonstrate such findings in that group, but it highlights the point that we cannot conclude from this study that the observed differences are entirely due to future risk for gestational diabetes, because we have that potential confounding of maternal BMI.

    The findings are consistent with the notion that, among women who are going to develop gestational diabetes, their offspring are likely at risk for overgrowth prior to the diagnosis of gestational diabetes, potentially related to the metabolic differences of the mother and the intrauterine environment. However, the caveat to recognize is that these data do not definitively establish that gestational diabetes is the sole driver of this risk differential for fetal overgrowth.

    • Ravi Retnakaran, MD, MSc, FRCPC
    • Professor of Medicine
      University of Toronto
      Endocrinologist, Leadership Sinai Centre for Diabetes
      Mount Sinai Hospital, Toronto

    Disclosures: Retnakaran reports no relevant financial disclosures.

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