Effects of Maternal Subclinical Hypothyroidism in Early Pregnancy Diagnosed by Different Criteria on Adverse Perinatal Outcomes in Chinese Women With Negative TPOAb

Abstract

Aims: To compare the effects of maternal subclinical hypothyroidism (SCH) diagnosed by the 2011 or 2017 “Guidelines of the American Thyroid Association (ATA) for the diagnosis and management of thyroid disease during pregnancy and the postpartum” during the first trimester on adverse pregnancy outcomes in thyroid peroxidase antibody (TPOAb)–negative pregnant women. Methods: There were 1,556 Chinese singleton pregnant women with negative TPOAb diagnosed with either SCH or euthyroidism who were investigated, and the prevalence and risk of obstetric outcomes were compared between the two groups using 2011 and 2017 ATA standards, respectively. The effects of a mildly elevated thyroid-stimulating hormone (TSH) concentration on adverse pregnancy outcomes were evaluated by binary logistic regression. Results: Maternal SCH identified by the 2011 ATA guidelines correlated with higher rates and risks of pregnancy-induced hypertension (PIH), preeclampsia, and low-birth-weight infants, while maternal SCH diagnosed by the 2017 ATA guidelines was more likely to develop PIH, preeclampsia, cesarean delivery, preterm delivery, placenta previa, and total adverse maternal and neonatal outcomes. Moreover, a mildly elevated TSH level was significantly associated with PIH after adjustment for confounding factors. Conclusions: Compared with the 2011 ATA guidelines, the 2017 ATA guidelines could be more applicable to Chinese pregnant women to screen the effects of SCH on the majority of adverse pregnancy outcomes.

Maternal Pre-Pregnancy Obesity Combined With Abnormal Glucose Metabolism Further Increases Adverse Pregnancy Outcomes in Chinese Pregnant Women

“…As depicted in our recent studies ( 8 , 9 ), adverse maternal outcomes consisted of PIH (defined as new-onset systolic blood pressure ≧̸140 mmHg and/or diastolic blood pressure ≧̸90 mmHg occurring after 20 weeks’ gestation), preeclampsia (defined as PIH combined with proteinuria 0.3 g/24 h), preterm delivery (the delivery < 37 weeks’ gestation), cesarean delivery (CS, recorded by the recorded on the delivery by a midwife or doctor), postpartum hemorrhage (blood loss ≧̸500 ml within the first 24 h of delivery), placental previa (the placenta grew in the lowest part of the uterus and covered all or part of the opening to the cervix), and abruption (the normally located placenta separated from the uterine site before the birth of fetus), as well as dystocia (abnormal or difficult childbirth or labor diagnosed by an obstetrician). Total adverse maternal outcomes were referred as one or more of the above complications.…”

“…This retrospective cohort study was based on data from our previous studies ( 8 , 9 ). In brief, 4,178 singleton pregnancies who underwent an oral glucose tolerance test (OGTT) during 24–28 weeks and delivered in the obstetrics department of Shanghai Jiao Tong University Affiliated Sixth People’s Hospital were continuously recruited during the period from January to December in 2016.…”

Relationship Between Subclinical Hypothyroidism in Pregnancy and Hypertensive Disorder of Pregnancy: A Systematic Review and Meta-Analysis

“…In this study, the incidence of clinical hypothyroidism was 4.42%, the incidence in the first trimester was 8.17%, and the incidence in the second and third trimesters was 3.27% [calculated using the data obtained according to the 2017ATA guideline as the diagnostic criteria in the study by Li, M.F., et al. and his colleagues ( 10 )]. The upper normal cut-off for TSH in this study was between 2.5 mIU/L and 5.78 mIU/L.…”

“…A total of 4808 patients with subclinical hypothyroidism, 94306 with euthyroidism, and the rest with other thyroid diseases [there is a part of the repeated population because Li, M.F., et al. and his colleagues assessed the same population with different diagnostic criteria, respectively ( 10 )].There were 15 prospective cohort studies ( 16 – 20 , 22 – 29 , 31 , 32 ) and 7 retrospective cohort studies ( 4 , 7 , 10 , 11 , 21 , 30 , 33 ). In addition, due to slight differences in thyroid parameters during different pregnancy periods, there were 10, 6, and 1 studies evaluating the relationship between subclinical hypothyroidism in pregnancy and HDP in the first, second, and third trimesters, respectively.…”

“…Up to now, there are various studies on whether maternal subclinical hypothyroidism is associated with HDP. Some studies believe that women with subclinical hypothyroidism in pregnancy are at risk of HDP compared with euthyroid pregnant women during pregnancy ( 10 , 11 ). However, the results of a META analysis showed no correlation between subclinical hypothyroidism in pregnancy and HDP ( 12 ).…”