Relationship between Thyroid Status during the First Trimester of Pregnancy and Neonatal Well-Being

Associations of Maternal Serum Iodine Concentration with Obstetric Complications and Birth Outcomes-Longitudinal Analysis Based on the Huizhou Mother-Infant Cohort, South China

This study aimed to explore the temporal associations between maternal serum iodine concentration (SIC) and common pregnancy outcomes in Chinese women. Eligible singleton pregnant women aged 20-34 years were selected, and their fasting blood samples were collected during early (T1, n = 1101) and mid-pregnancy (T2, n = 403) for SIC testing by inductively coupled plasma mass spectrometry. Multivariable linear regression indicated that log₁₀SIC at T1 (β = -0.082), T2 (β = -0.198), and their % change (β = -0.131) were inversely associated with gestational weight gain (GWG, all p < 0.05). Maternal log₁₀SIC at both T1 (β = 0.077) and T2 (β = 0.105) were positively associated with the Apgar score at 1 min (both p < 0.05). Women in the third quartile (Q3) of SIC at T1 had a lower risk of small for gestational age (SGA, OR = 0.405, 95% CI: 0.198-0.829) compared with those in Q4. Restricted cubic spline regression suggested a U-shaped association between SIC and SGA risk, and SIC above 94 μg/L at T1 was the starting point for an increased risk of SGA. The risk of premature rupture of membrane (PROM) increased by 96% (OR = 1.960, 95% CI: 1.010-3.804) in Q4 compared to that in Q1. Our longitudinal data from an iodine-replete region of China indicated that high maternal SIC could restrict GWG and improve Apgar scores at delivery, but might increase the risk of SGA and PROM.

Relationship between Serum TSH Level and Adverse Pregnancy Outcome in Advanced Maternal Age

The purpose of this paper is to explore the relationship between serum thyroid-stimulating hormone (TSH) levels and adverse pregnancy outcomes in advanced maternal age. A total of 97 elderly parturient women who were treated in our hospital from June 2020 to March 2021 are included in this study. According to the TSH level, the parturient women are divided into three groups, including A (<0.25 μIU/ml), B (>4.00 μIU/ml), and C (0.25–4.00 μIU/ml) groups. The clinical data of all parturients are collected and sorted out. The serum levels of TSH, free triiodothyronine (FT3), and free thyroxine (FT4) are measured by chemiluminescence immunoassay. The levels of immunoglobulin (Ig) A, IgG, and IgM are determined by immunoturbidimetry. The incidence of adverse pregnancy outcomes is analyzed. The birth weight and Apgar score of newborns in the three groups are compared. The TSH level in group A is significantly lower than that in groups B and C, but the levels of FT3 and FT4 in group A are notably higher than those in groups B and C (P < 0.05). The levels of IgA, IgG, and IgM in group A are significantly higher than those in groups B and C (P < 0.05). The incidence of adverse pregnancy outcomes in group C is 2.38%, which is obviously lower than the 20.00% in group A and 17.14% in group B (P < 0.05). The birth weight and Apgar score of infants in group A and group B are significantly lower than those in group C (P < 0.05). TSH has a great influence on the pregnancy outcome in advanced maternal age, which should be paid more attention in clinic.

Primary Congenital Hypothyroidism in Children Below 3 Years Old - Etiology and Treatment With Overtreatment and Undertreatment Risks, a 5-Year Single Centre Experience

Worldwide neonatal screening for congenital hypothyroidism (CH) is a gold standard of active surveillance in newborns. Prompt diagnosis, subsequent timely treatment implementation, and proper dosage of levothyroxine (L-T4) are crucial for normal growth and development, especially of the central nervous system. However, overtreatment may have a potential negative impact on further neurodevelopment. We retrospectively analysed data of 99 newborns with CH diagnosis, referred to the Endocrinology Outpatient Clinic of the Institute of Mother and Child in Warsaw, Poland from the CH screening program from 2017 to 2021. We evaluated the diagnostic process and treatment up to the age of 3 years. We compared groups of children from the first and the second screening groups (FSG, SSG) in the neonatal screening with an evaluation of ultrasound examination (thyroid dysgenesis vs. gland in situ, GIS). The overtreatment and undertreatment risks were assessed and an analysis of the new TSH thresholds was performed. Treatment was implemented at a median of 9 days of life (3 - 27); 8 days (3 - 17) in FSG and 19 (6 - 27) in SSG. The dose of L-T4 differed between FSG and SSG at all three analysed time points (start of the therapy, 12 months, and 3 years) with significantly higher doses in FSG. The same was observed for the patients with thyroid dysgenesis vs. GIS. Screening TSH level was ≥ 28mIU/l in 91.7% of patients with thyroid dysgenesis in comparison to 74.0% of patients with GIS (p= 0.038). The optimally treated group (fT4 in the upper half of the reference range, according to the guidelines) was up to 58.0% of the children during the follow-up. The risk for overtreatment was present in 1/5 of the study group after 12 months and 1/4 after 3 years of L-T4 therapy. Analysis of new TSH thresholds showed an increased prevalence of mild hypothyroidism, GIS, and either euthyroid state or overtreatment while treating with lower L-T4 doses in comparison to the rest of the cohort. The study confirmed the general efficacy of the CH diagnostic pathway and the timely implemented L-T4 therapy. The suspected overtreatment after the first 12 months of L-T4 therapy requires consideration of the earlier diagnosis re-evaluation.