This article is more than 5 years old. Information may no longer be current.
Iron deficiency seen with thyroid disorders during pregnancy
Click Here to Manage Email Alerts
Iron deficiency during the first trimester of pregnancy is common and associated with a higher prevalence of thyroid autoimmunity and higher thyroid-stimulating hormone and lower free thyroxine levels, recent published data show.
Iron deficiency can increase the risk for thyroid disorders and puts women at risk for miscarriages and preterm birth, according to the researchers.
Kris Poppe, MD, PhD, of the department of endocrinology, University Hospital CHU-St-Pierre in Brussels, and colleagues evaluated data on 1,900 women who attended the obstetrical clinic of the University Hospital CHU St-Pierre from 2013 to 2014 to compare the prevalence of thyroid autoimmunity and dysfunction during the first trimester of pregnancy in women with and without iron deficiency.
Kris Poppe
Ferritin, thyroid peroxidase antibodies (TPO-Ab), TSH and free T4 were measured, and age and BMI were recorded at the first antenatal visit. Ferritin less than 15 µg/L was defined as iron deficient, TPO-Ab greater than 60 kIU/L as thyroid autoimmunity and TSH greater than 2.5 mIU/L as subclinical hypothyroidism.
Among all participants, 3.1% had suppressed TSH levels and 35% had iron deficiency. The group with iron deficiency had lower serum ferritin levels (10 µg/L) compared with the group without iron deficiency (312 µg/L; P < .001); free T4 levels also were lower in the group with iron deficiency (1 ng/dL vs. 1.1 ng/dL; P < .001). The group with iron deficiency had higher serum TSH levels (1.5 mIU/L) compared with the group without iron deficiency (1.3 mIU/L; P = .015).
The group with iron deficiency had a higher prevalence of thyroid autoimmunity (10% vs. no iron deficiency, 6%; P = .011) and subclinical hypothyroidism (20% vs. 16%; P = .049) compared with the group without iron deficiency.
Iron deficiency was linked to an increased risk for thyroid autoimmunity (OR = 1.57; 95% CI, 1.11-2.21) and subclinical hypothyroidism (OR = 2.31; 95% CI, 1.59-3.37). However, iron deficiency was not linked to age or BMI.
There was an inverse relationship between ferritin and serum TSH levels (P = .027).
In the univariable analysis, a higher risk for subclinical hypothyroidism was observed in participants with iron deficiency (OR = 1.29; 95% CI, 1.01-1.64), age younger than 30 years (OR = 0.76; 95% CI, 0.6-0.96) and thyroid autoimmunity (OR = 2.32; 95% CI, 1.59-3.37).
“Iron deficiency is still present in 2016, even in an urban area,” Poppe told Endocrine Today. “The pregnant women’s iron status should at least be checked once during pregnancy, during the first trimester. Women with a pregnancy wish, should take attention that their intake of iron-rich food in maintained and/or increased. Depending on the area, city or country where the women live, it can be advised to take multivitamin products containing iron before and during pregnancy.”– by Amber Cox
For more information:
Kris Poppe, MD, PhD, can be reached at kris_poppe@stpierre-bru.be.
Disclosure: Poppe reports financial ties with Merck.
Click Here to Manage Email Alerts