Background: Despite some studies indicating that thyroid antibody positivity during pregnancy has been associated with adverse pregnancy outcomes, evidence regarding the effects of levothyroxine (LT4) treatment of euthyroid/subclinical hypothyroid pregnant women with autoimmune thyroid disease on pregnancy outcome is limited. We aimed to assess whether pregnant women with autoimmune thyroid disease, but without overt thyroid dysfunction are affected by higher rates of adverse pregnancy outcomes. In addition, we aimed to explore whether LT4 treatment improves the pregnancy outcome of affected women. Methods: A prospective study was carried out on pregnant women from the first trimester to delivery. The study was conducted among pregnant women receiving prenatal care in centers under coverage of Shahid Beheshti University of Medical Sciences. Of a total of 1746 pregnant women, screened for thyroid dysfunction, 1028 euthyroid TPOAb-negative (TPOAb⁻) and 131 thyroid peroxidase antibody-positive (TPOAb⁺) women without overt thyroid dysfunction entered the second phase of the study. TPOAb⁺ women were randomly divided into two groups: group A (n = 65), treated with LT4 and group B (n = 66), received no treatment. The 1028 TPOAb⁻ women (group C) served as a normal population control group. Primary outcomes were preterm delivery and miscarriage and secondary outcomes included placenta abruption, still birth, neonatal admission and neonatal TSH levels. Results: Groups A and C displayed a lower rate of preterm deliveries compared with group B (RR = 0.30, 95% CI: 0.1–0.85, P = 0.0229) and (RR = 0.23, 95% CI: 0.14–0.40, P < 0.001) respectively. There was no statistically significant difference in the rates of preterm labor between groups A and C (RR = 0.79, 95% CI: 0.30–2.09, P = 0.64). The number needed to treat (NNT) for preterm birth was 5.9 (95% CI: 3.33–25.16) Conclusions: Treatment with LT4 decreases the risk of preterm delivery in women who are positive for TPOAb.

Context Currently, there is no consensus on universal thyroid screening and levothyroxine (LT₄) treatment of pregnant women with subclinical hypothyroidism (SCH) who are negative for thyroid peroxidase antibody (TPOAb⁻). Objective We aimed to evaluate the benefits of LT₄ treatment on pregnancy outcomes in SCH-TPOAb⁻ women. Design This study was conducted within the framework of the Tehran Thyroid and Pregnancy Study. A single-blind randomized clinical trial was undertaken in pregnant women who were SCH-TPOAb⁻. Setting Prenatal care centers of the Shahid Beheshti University of Medical Sciences. Patients Using the thyrotropin (TSH) cut point of 2.5 mIU/L, 366 SCH-TPOAb⁻ and 1092 euthyroid TPOAb⁻ women were recruited. Intervention SCH-TPOAb⁻ women were randomly assigned to two groups: group A (n = 183) who were treated with LT₄ and group B (n = 183) who received no treatment. A total of 1,028 euthyroid TPOAb⁻ women served as the control group (group C). Main Outcome Measure The primary outcome was the rate of preterm delivery. Results Using the TSH cutoff of 2.5 mIU/L, no significant difference in preterm delivery was observed between groups A and B [relative risk (RR): 0.86; 95% confidence interval (CI): 0.47 to 1.55; P = 0.61]. However, log-binomial model analysis based on a cut point of 4.0 mIU/L demonstrated a significantly lower rate of preterm delivery in LT₄-treated women compared with those who received no treatment (RR: 0.38; 95% CI: 0.15 to 0.98; P = 0.04). Conclusions Despite no beneficial effect of LT₄ therapy in reducing preterm delivery in SCH-TPOAb⁻ women with a TSH cut point of 2.5 to 4 mIU/L, LT₄ could precisely decrease this complication using the newly recommended cutoff ≥4.0 mIU/L.

Pregnant women are one of the endangered groups who need special attention in the COVID-19 epidemic. We conducted a systematic review and summarised the studies that reported adverse pregnancy outcomes in pregnant women with COVID-19 infection. A literature search was performed in PubMed and Scopus up to 1 September 2022, for retrieving original articles published in the English language assessing the association between COVID-19 infection and adverse pregnancy outcomes. Finally, in this review study, of 1790 articles obtained in the initial search, 141 eligible studies including 1,843,278 pregnant women were reviewed. We also performed a meta-analysis of a total of 74 cohort and case-control studies. In this meta-analysis, both fixed and random effect models were used. Publication bias was also assessed by Egger’s test and the trim and fill method was conducted in case of a significant result, to adjust the bias. The result of the meta-analysis showed that the pooled prevalence of preterm delivery, maternal mortality, NICU admission and neonatal death in the group with COVID-19 infection was significantly more than those without COVID-19 infection (p<.01). A meta-regression was conducted using the income level of countries. COVID-19 infection during pregnancy may cause adverse pregnancy outcomes including of preterm delivery, maternal mortality, NICU admission and neonatal death. Pregnancy loss and SARS-CoV2 positive neonates in Lower middle income are higher than in High income. Vertical transmission from mother to foetus may occur, but its immediate and long-term effects on the newborn are unclear.

Pregnancy has a huge impact on the thyroid function in both healthy women and those that have thyroid dysfunction. The prevalence of thyroid dysfunction in pregnant women is relatively high. The objective of this review was to increase awareness and to provide a review on adverse effect of thyroid dysfunction including hyperthyroidism, hypothyroidism and thyroid autoimmune positivity on pregnancy outcomes. In this review, Medline, Embase and the Cochrane Library were searched with appropriate keywords for relevant English manuscript. We used a variety of studies, including randomized clinical trials, cohort (prospective and retrospective), case-control and case reports. Those studies on thyroid disorders among non-pregnant women and articles without adequate quality were excluded. Overt hyperthyroidism and hypothyroidism has several adverse effects on pregnancy outcomes. Overt hyperthyroidism was associated with miscarriage, stillbirth, preterm delivery, intrauterine growth retardation, low birth weight, preeclampsia and fetal thyroid dysfunction. Overt hypothyroidism was associated with abortion, anemia, pregnancy-induced hypertension, preeclampsia, placental abruption, postpartum hemorrhage, premature birth, low birth weight, intrauterine fetal death, increased neonatal respiratory distress and infant neuro developmental dysfunction. However the adverse effect of subclinical hypothyroidism, and thyroid antibody positivity on pregnancy outcomes was not clear. While some studies demonstrated higher chance of placental abruption, preterm birth, miscarriage, gestational hypertension, fetal distress, severe preeclampsia and neonatal distress and diabetes in pregnant women with subclinical hypothyroidism or thyroid autoimmunity; the other ones have not reported these adverse effects. While the impacts of overt thyroid dysfunction on feto-maternal morbidities have been clearly identified and its long term impact on childhood development is well known, data on the early and late complications of subclinical thyroid dysfunction during pregnancy or thyroid autoimmunity are controversial. Further studies on maternal and neonatal outcomes of subclinical thyroid dysfunction maternal are needed.