Measuring hCG may predict preeclampsia risk in women with high-normal thyroid function
Testing measurements of human chorionic gonadotropin, or hCG, in pregnant women with high-normal thyroid function tests may help improve identification of those who may be at risk for preeclampsia, according to study findings presented at the European Congress of Endocrinology.
“This is the first evidence that suggests that an additional measurement of hCG can improve the interpretation of thyroid function during pregnancy,” Tim Korevaar, MD, MSc, of Erasmus University Medical Center in Rotterdam, the Netherlands, told Endocrine Today. “Moreover, our data on the risk of preeclampsia suggest that already subclinical forms of hyperthyroidism pathology may be a risk factor for preeclampsia.”
Korevaar and colleagues evaluated data from 5,153 women for measurements of thyroid-stimulating hormone, free thyroxine, hCG and thyroid peroxidase (TPO)-antibody during early pregnancy (< 18 weeks’ gestation).
“We hypothesized that women with high-normal thyroid function due to high hCG levels would have a different risk of preeclampsia as compared to women with high-normal thyroid function and low hCG,” the researchers wrote.
Multivariable logistic regression stratified per 20,000 IU/L hCG (up to 60,000 IU/L) was used to analyze the association between high-normal free T4 or low TSH with preeclampsia.
A combination of high-normal free T4 levels and low hCG (< 20,000 IU/L) yielded an 11.1-fold increased risk for preeclampsia (P < .05). Low TSH and low hCG also increased the risk for preeclampsia: 9.2-fold increased risk for TSH less than 0.1 mU/L; 8.7-fold increased risk for TSH less than the 5th percentile; and a 3.8-fold increased risk for TSH less than 0.4 mU/L (P < .05 for all). There was no increased risk for preeclampsia with a combination of high-normal free T4 and hCG greater than 20,000 IU/L or low TSH and hCG greater than 20,000 IU/L.
“Although more studies are needed to verify our results, our data suggest that hCG measurements can distinguish women with a physiological high thyroid function from women with a more pathological underlying cause of high thyroid function,” Korevaar told Endocrine Today. “Women with the latter are likely to benefit from more thorough follow-up and potentially even treatment. On the other hand, our data confirm that women with high thyroid function due to high hCG are unlikely to benefit from treatment.” – by Amber Cox
Korevaar T, et al. Abstract OC4.1. Presented at: European Congress of Endocrinology; May 28-31, 2016; Munich.
Disclosure: Korevaar reports no relevant financial disclosures.