Most Read Articles
Tristan Manalac, 05 Nov 2019
Vaping nontraditional e-cigarette flavours, such as fruit and candy, supports the habit and may promote more frequent use, according to a new study.
Stephen Padilla, 31 Oct 2019
Intraoperative epidural analgesia, perioperative opioid and total dose of volatile agent appear to show some “clinically meaningful associations” with relapse-free survival (RFS) in children with solid organ tumour, particularly in paediatric sarcoma patients, according to a Singapore study. However, no statistically significant association exists between epidural use and an improved RFS.

Maternal heavy metal exposure may lead to reduced birthweight

30 Sep 2019
Harmful substances such as heavy metals are found in a broad spectrum of counterfeit and home-grown brands of cosmetics and skincare products.

Maternal exposures to heavy metals vanadium (V), arsenic (As) and lead (Pb) at early pregnancy appear to result in lower maternal free T3 (FT3) and FT3/free T4 (FT4) ratio, which may contribute to reduced birthweight, suggests a recent study.

“Mediation analyses indicated that maternal thyroid hormone was a possible mediator of the association between urinary heavy metals and birth size,” the authors said.

Maternal urinary V was inversely associated with FT3 and FT3/FT4 ratio levels, while urinary As and Pb were inversely associated with FT3. Moreover, maternal FT3 and FT3/FT4 ratio were positively associated with birthweight.

In mediation analyses, maternal FT3 or FT3/FT4 ratio appeared to facilitate 5.33–30.57 percent of the associations among V, As and Pb levels and birth size.

“Maternal thyroid hormones during pregnancy play a critical role in foetal development,” according to the authors.

In an earlier study involving Chinese pregnant women, an inverse association was also found between thyroid hormone concentrations and levels of heavy metals (ie, As, manganese and antimony). [Environ Int 2018;121:1185-1192]

The current cohort study conducted in China measured the concentrations of heavy metals in urine samples and thyroid hormones in blood samples of 675 pregnant women during early pregnancy. Multivariable linear regressions were used to examine the associations of maternal urinary heavy metal levels with both maternal thyroid hormones and birth outcomes.

In addition, the authors performed mediation analyses to evaluate the mediation role of thyroid hormones in these associations.

Digital Edition
Asia's trusted medical magazine for healthcare professionals. Get your MIMS JPOG - Malaysia digital copy today!
Sign In To Download
Editor's Recommendations
Most Read Articles
Tristan Manalac, 05 Nov 2019
Vaping nontraditional e-cigarette flavours, such as fruit and candy, supports the habit and may promote more frequent use, according to a new study.
Stephen Padilla, 31 Oct 2019
Intraoperative epidural analgesia, perioperative opioid and total dose of volatile agent appear to show some “clinically meaningful associations” with relapse-free survival (RFS) in children with solid organ tumour, particularly in paediatric sarcoma patients, according to a Singapore study. However, no statistically significant association exists between epidural use and an improved RFS.