Maternal thyroid status and its relation to ferritin and vitamin B12 in Saudi pregnant women

Abstract

BackgroundThyroid dysfunction is a worldwide phenomenon in women, and the prevalence increases during pregnancy, with hypothyroidism being the most common. In most developing countries, nutritional deficiencies of nearly all essential nutrients, including iron, vitamin B12, and folic acid, are common in pregnant women. Thyroid disorders and nutritional deficiencies especially of iron and vitamin B12 cause a number of maternofetal complications.ObjectivesTo assess thyroid status in pregnant Saudi women and explore its relation to ferritin and vitamin B12.Patients and methodsThis was a cross-sectional study conducted at antenatal clinics of the Northern Area Armed Forces Hospital, KSA, enrolling 254 Saudi women: 180 pregnant [classified according to gestational age into group A (first trimester) and group B (second trimester)], and 74 age-matched healthy nonpregnant women, as control group (group C). After a detailed obstetrical and medical history, and clinical assessment, participants were subjected to laboratory investigations in the form of thyroid function by measuring thyroid-stimulating hormone (TSH) and free thyroxin, hemoglobin (HB), serum ferritin, and vitamin B12 levels.ResultsTSH level was lower in pregnant than nonpregnant women. Subclinical hypothyroidism (35.5%) was the most common thyroid disorder followed by overt hypothyroidism (10%) and hypothyroxinemia (2.2%) in pregnant women. HB and vitamin B12 levels were significantly lower in first and second trimesters of pregnancy when compared with controls (P=0.001). Serum free thyroxin correlated positively with HB and ferritin, whereas TSH correlated negatively with HB and ferritin.ConclusionHigh prevalence of hypothyroidism in pregnant females and its association with iron and vitamin B12 deficiencies highlight the urgent need for thyroid status to be detected and to evaluate nutritional deficiencies in such group, so as to start early treatment promptly and to prevent the adverse effects of the disorder to both mother and fetus to achieve normal pregnancy outcome.