Study of thyroid disorders in pregnancy and their effects on feto-maternal outcomes

Introduction

The second most prevalent endocrine problem during pregnancy is thyroid abnormalities, which include hypothyroidism, subclinical hypothyroidism, hyperthyroidism, and subclinical hyperthyroidism.¹ During pregnancy, the mother’s thyroid gland undergoes several changes. If a patient is unable to adjust to these changes, her thyroid function becomes erratic.² It is well recognized that both overt and subclinical thyroid disorders have negative effects on the growing fetus and expectant mothers.

Before or during pregnancy, thyroid disorders can have a variety of effects, including reduced fertility, damage to the trophoblast or embryo, increased risk of miscarriage and stillbirth, higher rates of congenital abnormalities, cretinism, infant mortality, and disruption in psychomotor development.³

Profound deficiency gives rise to both maternal and fetal hypothyroidism, contributing to adverse obstetric consequences, such as stillbirths, spontaneous abortion, and preterm birth.⁴ Maternal thyroid hormones play a vital role in fetal brain development, particularly during the first 20 weeks of gestation.⁵ Pregnancy outcomes and cognitive development of the fetus are both greatly affected by thyroid problems.^6,7 Prenatal neurodevelopmental problems are caused by anomalies in the thyroid stimulating hormone (TSH) production or elevated serum T4 levels.^7,8 During the initial stages of pregnancy, deficiencies in thyroid synthesis (hypothyroidism, subclinical hypothyroidism, and hypothyroxinemia) and the presence of thyroid antibodies are linked to compromised intelligence and motor skills in offspring.

Protocol

Methods

Ethical clearance was obtained from the institutional ethics committee. After informed, valid, and written agreement was acquired, each woman was informed about the study’s design and goals, as well as the importance of assessing thyroid function tests in pregnant women and their effects on fetal and maternal outcomes. We submitted applications for intramural grants, synopsis concessions, and ICMR money. A total of 165 pregnant women with deranged TSH levels who met the inclusion and exclusion criteria were observed. Thyroid function tests will be performed before 13 weeks of pregnancy. Pregnant women with a deranged thyroid profile will be followed through birth, and the postpartum period and neonates will be followed until 21 days of life. There will be a thorough review of your menstrual, obstetric, personal, and family histories. A thyroid function test of the neonate was performed on day 4 of life.

Venous blood samples will be obtained from the patient to assess the serum TSH, free T3, and free T4 levels. Samples will be taken and allowed to clot in a test tube devoid of anticoagulants.

Vital Immuno-Diagnostic Assay System tests were performed on the subjects (VIDAS). If abnormal serum TSH levels were discovered, VIDAS was used to examine the FT3 and FT4 readings. All panel tests were based on the enzyme-linked fluorescent assay (ELFA) method.

Discussion

The purpose of this study was to assess pregnancy outcomes in women with abnormal thyroid function test results. All women who had been diagnosed with abnormal thyroid function test results started on treatment and were followed up until delivery.³

Treatment is recommended for pregnant women with overt or subclinical hypothyroidism regardless of the presence of TPO antibodies. Levothyroxine is recommended for both overt and subclinical hypothyroidism, regardless of the presence of TPO antibodies.

Early recognition and proper management of thyroid dysfunction in pregnant women are crucial, as poorly controlled thyrotoxicosis substantially amplifies the chances of adverse fetomaternal outcomes. Additionally, maternal thyroid-stimulating antibodies or antithyroid agents pass through the placenta, both of which could potentially disturb fetal thyroid activity, which might affect the fetal outlook.⁹

Previous research has indicated a higher prevalence of thyroid issues in younger age groups. These differences could be attributed to demographic shifts such as delayed marriages, delayed pregnancies, and longer gaps between childbirths. Moreover, disparities between urban and rural areas are more pronounced in patients with hypothyroidism. Additionally, a significant number of pregnant women with thyroid disorders have lower levels of education. This factor may contribute to a lack of awareness and disregard for early symptoms, leading to inappropriate healthcare-seeking behaviors and potential complications during pregnancy.¹⁰

It has been observed that many hyperthyroid women tend to have multiple pregnancies. Multiple pregnancies can deplete micronutrients and other essential elements, potentially leading to thyroid dysfunction in multi-gravida women. Furthermore, there are fewer chances of hypothyroid women with spontaneous labor, and they are at a higher risk of undergoing caesarean section.

The increasing costs of thyroid profile testing in the private healthcare sector and, in contrast, limited access to laboratories offering these tests in the government sector result in the underdiagnosis of subclinical thyroid dysfunction during its early stages.¹¹

This underscores the importance of routine screening for thyroid disorders during antenatal checkups in all pregnant individuals.

Among individuals with hyperthyroidism, abortion is most common. Hypothyroidism, on the other hand, is associated with low birth weight (LBW) because of its association with conditions such as preeclampsia. Insufficient fetal thyroxine levels can disrupt the development of the newborn’s pituitary-thyroid axis, growth hormone secretion in the fetal pituitary gland, vascular responsiveness and maturation, and cardiovascular balance during fetal development.¹¹

In addition, a number of problems such as preterm birth, jaundice, respiratory distress syndrome, neonatal sepsis, meconium aspiration syndrome, and birth asphyxia can occur in newborns born to women with thyroid abnormalities.¹¹