A Longitudinal Study of Changes in Thyroid Related Hormones among Pregnant Women Residing in an Iodine Deficient Urban Area

Levothyroxine dosages during pregnancy among hypothyroid women. An experience from a tertiary care center of Karachi, Pakistan, based on data from Maternal Hypothyroidism on Pregnancy Outcomes Study (MHPO-5)

Objectives

The dosage of levothyroxine (LT4) during pregnancy differs among different ethnic groups worldwide. These differences are due to variations in geographical iodine distribution, autoimmunity, and variations in thyrotropin (TSH) targets for pregnancy. To the best of our knowledge, we report the levothyroxine dosage prescribed during pregnancy in hypothyroid women, for the first time from Pakistan.

Results

Levothyroxine dosage of 280 hypothyroid women during pregnancy were reviewed. The median LT4 dosages prescribed before conception was 85.7 mcg per day which increased by 14.3 mcg per day in the first trimester (P 0.001). A significant difference in dosage was observed between controlled and uncontrolled TSH groups in the first trimester (P 0.05). Lower LT4 dosage was prescribed for subclinical hypothyroid women as compared to overt hypothyroid cases, whereas dosages did not differ according to autoimmune status in the latter part of gestation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-05984-7.

Infants of Hypothyroid Mothers at Risk of Developing Hypothyroidism: A Cross-sectional Study in Qassim Region of Saudi Arabia

Introduction Hypothyroidism is one of the most prevalent endocrine disorders in women of childbearing age. If it goes untreated, can seriously affect maternal and fetal outcomes.Aim This study aimed to assess the prevalence of hypothyroidism in infants born to hypothyroid mothers and to analyze associated fetal complications.Subjects and methods This is a quantitative cross-sectional study conducted among pregnant mothers at Al Qassim region, Saudi Arabia. Data of pregnant women with clinical hypothyroidism during the last five years 2015-2019 were obtained from visiting records of Endocrine Clinic in Qassim University. These participants were contacted and written informed consents were obtained from the participants after a brief introduction of the study. A comprehensive survey questionnaire was used to collect information about demographic and study variables. Results 153 mothers were enrolled. The most common age group was 31 – 45 years with mostly Saudis (93.5%). Complications during pregnancy were detected among 47.1% of mothers. The most common complication during pregnancy was C-section (26.8%). The prevalence of infants with hypothyroidism was 2.6% while the prevalence of newborn babies with temporary/permanent hypothyroidism was 4.6%. Decreased activity (7.8%) and an increased in weight (5.2%) were the most common symptoms of a child at the time of diagnosis.Conclusion Infants with hypothyroidism were not widely prevalent in this study. Cesarean delivery, gestational diabetes and anemia were some of the most common maternal complications during pregnancy.Keywords  

Mild-to-moderate iodine deficiency in a sample of pregnant women and salt iodine concentration from Zhejiang province, China

Since 2011, Zhejiang province has eliminated iodine deficiency disorders (IDD) in its populations. Following this achievement, a new revised iodine concentration in iodised salt was implemented in Zhejiang in 2012. However, the re-emergence of iodine deficiency has been reported in pregnant women. Therefore, the aim of this study was to assess household salt iodine concentration and iodine status of pregnant women in Zhejiang province, China. We conducted a cross-sectional study between April 2018 and August 2018 in Quzhou, Zhejiang province. Pregnant women aged ≥ 18 years who did not have a history of thyroid disease were recruited into the study. They were asked to complete socio-demographic questionnaires including a food frequency questionnaire (FFQ). In addition, a spot urine sample and a household table salt sample were also provided by each participant. A total of 625 pregnant women agreed to participate. The overall median urinary iodine concentration (UIC) was 130 µg/L, indicating mild-to-moderate iodine deficiency in pregnant women. The coverage of iodised salt was 85.2%, and of these, the rate of adequately iodised salt was 98.1%. In conclusion, our results confirmed the re-emergence of iodine deficiency in pregnant women as reported by other studies conducted in Zhejiang province. Therefore, urgent public health actions are needed to improve iodine status of pregnant women in order to prevent the adverse consequences of IDD on the neurodevelopment of foetus.

Thyroid Screening During Early Pregnancy and the Need for Trimester Specific Reference Ranges: A Cross-Sectional Study in Lahore, Pakistan

Background

Derangements in thyroid hormone levels can cause multiple complications in the mother and the foetus. Thyroid stimulating hormone (TSH) and free thyroxine (free T4 or FT4) levels are used to screen for maternal thyroid dysfunction; these should be compared with population based trimester-specific reference ranges. Our goal was: to determine the prevalence of various thyroid derangements, in early pregnancy, according to the current reference ranges available; to determine the need for trimester specific reference ranges for the local population.

Methods

A multi-centric, cross sectional population survey was conducted in Lahore, Pakistan. Serum TSH and FT4 levels were measured at the hormone lab of the Pathology department of Combined Military Hospital (CMH) Lahore. The results were entered and analysed using Statistical Package for the Social Sciences (SPSS) version 23. 

Results

In the 293 women sampled, mean FT4 and TSH levels were 15.03 (±5.62) pmol/L and 2.53 (±6.82) mIU/L respectively. According to the laboratory specific reference ranges, the prevalence of overt hyperthyroidism was 4.10%, (mean TSH= 0.03mIU/L); subclinical hyperthyroidism was 16.38%, (mean TSH= 0.17mIU/L); normal 70.65%, (mean TSH = 1.29mIU/L); subclinical hypothyroidism 4.44%, (mean TSH= 15.11mIU/L); overt hypothyroidism 4.44%, (mean TSH = 20.60mIU/L).

Conclusion

Our study showed a significant prevalence of thyroid dysfunction in the first trimester of pregnancy, and therefore highlights the need for more rigorous thyroid screening of women, in early pregnancy. There is a need to monitor these women in order to reduce maternal and foetal complications. Trimester specific reference ranges for thyroid hormones need to be developed in Pakistan.

Iodine Deficiency in Zhejiang Pregnant Women in the Context of Universal Salt Iodization Programme

Zhejiang introduced universal salt iodization (USI) programme in 1995 and has achieved the goal of elimination of iodine deficiency disorders (IDD) since 2011. However, no systematical data of iodine nutritional status in population in pregnancy is available. In this cross-sectional study, pregnant women were interviewed to complete questionnaires in addition to handing in samples of urine and household table salt between March 2016 to February 2017. Date of birth, age of pregnancy, ethnicity and dietary iodine habits were recorded. The overall median urinary iodine concentration in 8561 pregnant women was 130.47 µg/L, which was lower than the cut-off value of iodine sufficiency of 150 µg/L recommended by the WHO. Participants using non-iodized salt, taking non-iodine-containing supplements, in coastal and in Han group were independently associated with iodine deficiency. The current USI programme did not supply Zhejiang pregnant women with sufficient iodine intake. They are generally iodine deficient, which have great public health importance since even mild IDD in pregnancy have adverse effects on fetal neurodevelopment. We strongly recommend urgent measures to improve iodine intake in pregnancy.

Turmeric use is associated with reduced goitrogenesis: Thyroid disorder prevalence in Pakistan (THYPAK) study

INTRODUCTION

South Asian population has a particularly high prevalence of thyroid disorders mainly due to iodine deficiency and goitrogen use. There is no data available for prevalence of thyroid disorders in the general population living in nonmountainous regions of Pakistan.

MATERIALS AND METHODS

A total of 2335 residents of Pak Pattan, Punjab, Pakistan were interviewed about demographic, dietary, medical and environmental history as well as screened for goiter. Individuals of all ages and either gender were included.

RESULTS

Median age was 34 (10-88) years and 1164 (49.9%) were males. Median monthly income was 49 (3.9-137) USD. Six hundred and sixty-nine (28.7%) subjects had palpable goiter. 77.5% (n = 462) and 22.5% (n = 133) had World Health Organization Grade I and Grade II goiters respectively, further screened by measuring thyroid-stimulating hormone (TSH). In subjects with TSH <0.4 mg/dL, free T3 and free T4 levels were measured. In 185 goiter subjects when TSH was measured, 50% (n = 93) were euthyroid, 48% (n = 89) were hyperthyroid, and one subject each was hypothyroid and subclinically hyperthyroid. 29/89 hyperthyroid subjects underwent radionuclide scanning. Twelve subjects had heterogeneous uptake consistent with multinodular goiter, 12 subjects had diffuse uptake, two had cold nodules and two had hyperfunctioning single nodules. Goiter was significantly more common among females, unmarried individuals and individuals drinking tube well (subterranean) water. Goiter was less common among those who consumed daily milk, daily ghee (hydrogenated oil), spices, chilies, and turmeric.

DISCUSSION

In our study population, goiter was endemic with very high prevalence of hyperthyroidism. Turmeric use was association with reduced goitrogenesis. Further studies to assess iodine sufficiency, thiocyanate exposure and autoimmunity need to be conducted. Masses consuming high goitrogen diets should be educated to incorporate turmeric, spices and green chilies in their cooking recipes, to reduce the risk of goiter development. In addition, use of iodized salt in their daily diet cannot be overemphasized.

Embolic suppurative thyroiditis with concurrent carcinoma in pregnancy: lessons in management through a case report

BACKGROUND

The thyroid undergoes a variety of physiological changes during pregnancy. The relatively low iodine levels seen in pregnancy have been implicated in thyroid growth during this time. Management of thyroid cancer in pregnancy is not immediately apparent. Furthermore, acute suppurative thyroiditis is rare and this is attributed to the glands innate immunity. We thoroughly review the evidence regarding management of thyroid abscess and thyroid malignancy during pregnancy and illustrate it via an extremely rare case of an embolic thyroid abscess highlighting an underlying carcinoma in a pregnant woman.

CASE

A 29-year old female was found to have a thyroid mass during an antenatal assessment. Following a wound infection from Caesarian section she developed a rapidly progressive thyroid abscess. Incision and drainage of the abscess, and subsequent histology revealed papillary carcinoma. She subsequently underwent both total thyroidectomy with level 6 dissection and radio-iodine ablation post-natally.

CONCLUSION

The literature is inconsistent regarding pregnancy as a risk factor for thyroid cancer, but overall it has been suggested as equally or slightly more frequent than in the non-pregnant population. Thyroid mass investigation should be as for the non-pregnant population. In the first trimester any endocrine surgery is associated with miscarriage, whereas these risks are reduced in second trimester. Importantly, there is no survival benefit in undergoing papillary carcinoma surgery in the third trimester versus early post partum and the risks of premature labour may outweigh any benefit gained by operating early. Most importantly, acute suppurative thyroiditis is rare entity and clinicians should have a low threshold for suspicion of underlying malignancy in these patients. This is especially true in the pregnant population who may be especially susceptible whilst undergoing hypertrophic thyroid changes.

Low maternal iodine intake and early pregnancy hypothyroxinemia: Possible repercussions for children

OBJECTIVE

Recent studies have shown that early pregnancy hypothyroxinemia (lower free thyroxin [FT4] and normal thyroid stimulating hormone [TSH] concentration) has deleterious effects on neuro-intellectual development of children. This study was designed to know its incidence in local pregnant women.

MATERIALS AND METHODS

Urinary iodine (UI) and serum thyroid related hormone (FT4, free triiodothyronine [FT3], and TSH) were determined in 254 pregnant women during the first trimester. UI and thyroid related hormones were determined by colorimetric (Sandell-Kolthoff) and radioimmunoassay method respectively.

RESULTS

Most of the pregnant women (n = 202; 79.5%) were iodine deficient (ID; UI <100 μg/L) and only 52 (20.5%) women were taking sufficient iodine (IS; UI ≥ 100 μg/L). Mean levels of FT4, FT3, and TSH were 13.0 ± 2.8 pmol/L, 3.8 ± 1.1 pmol/L and 1.2 ± 1.1 mIU/L, respectively. Maternal FT4 levels were significantly correlated with UI (r = 0.36; P < 0.001). Mean FT4 level in IS women was significantly (P < 0.05) higher than ID women. However, mean FT3 and TSH levels were not significantly different in both groups. FT4 reference range in IS pregnant women was 10.2-19.4 pmol/L. Hypothyroxinemia (FT4 <10.2 pmol/L and TSH <2.5 mIU/L) was diagnosed in 30 (11.8%) pregnant women. Its incidence was almost entirely confined to ID pregnant women with an odd ratio of 8.5 (95% confidence interval: 1.1-64.3).

CONCLUSION

About 12% pregnant women residing in urban areas of Pakistan are hypothyroxinemic because of low iodine intake.