Maternal and perinatal outcome in pregnancy with hypothyroidism

Association of maternal TSH and neonatal metabolism: A large prospective cohort study in China

AIMS

Neonatal metabolites are very important in neonatal disease screening, and maternal thyroid hormones play an important role in fetal and neonatal health. Our study aimed to explore the association of maternal thyroid hormones with neonatal metabolites and identify an important time windows.

METHODS

Pregnant women were recruited in Jinan Maternity and Child Care Hospital and followed up until delivery. Multivariate generalized linear regression models (GLMs) and restricted cubic spline (RCS) regression analysis models were used to investigate the associations of maternal TSH and FT4 with neonatal metabolites.

RESULTS

In total, 6,653 pairs of mothers and newborns were enrolled in our study. We identified 5 neonatal metabolites, including arginine/ornithine (Arg/Orn), C14:1/C2, C18:1, C3DC+C4OH and C8:1, that were significantly associated with maternal serum TSH during the whole pregnancy (P < 0.05), especially in the first trimester. Moreover, 10 neonatal metabolites were significantly associated with maternal serum FT4 (P < 0.05), most of which had positive correlations with maternal FT4 in the first trimester (P < 0.05). Some neonatal metabolites also had linear or nonlinear dose-effect relationships with maternal serum TSH and FT4 during the whole pregnancy, particularly in the first trimester.

CONCLUSIONS

Our study, for the first time, provides epidemiological evidence that maternal serum TSH and FT4, especially during the first trimester, are associated with linear or nonlinear variations in neonatal metabolites. Efforts to identify newborn metabolism levels should carefully consider the effects of maternal thyroid function.

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

Iodine is an essential micronutrient for the synthesis of thyroid hormones. The proper functioning of the thyroid axis is essential for the normal development of the nervous system, especially in the first trimester of gestation. The aim of the present study was to analyze the perinatal outcomes, anthropometry, and APGAR test scores of newborns and to relate them to maternal thyroid status. A total of 190 newborns participated in the study. No correlation was found between thyroid stimulating hormone (TSH) and maternal ioduria values in the first trimester of gestation with the weight or length of the newborn, or the APGAR score at one minute after birth. However, we found significant differences between the APGAR scores of children whose mothers had an iodine sufficiency level in the first trimester compared to the children of mothers with iodine deficiency. Similarly, the APGAR scores of children whose mothers had a TSH > 4 have significantly better APGAR scores than the children of mothers with a TSH < 4. Likewise, we found significant differences between the measurements of the newborns depending on whether their mothers smoked. The children of mothers who took iodine supplements or iodized salt obtained the highest APGAR score at one and five minutes after birth. It is essential to focus on recommending adequate consumption of iodine supplements and iodized salt prior to gestation and at least during the first trimester to achieve better fetal well-being.

Pregnancy outcomes and relationship to treatment adequacy in women treated early for congenital hypothyroidism: a longitudinal population-based study

CONTEXT

Untreated hypothyroidism is associated with a higher risk of adverse obstetric and neonatal outcomes. Pregnancy complications have yet to be evaluated in patients treated early for congenital hypothyroidism (CH).

OBJECTIVE

This study aimed to investigate pregnancy outcomes and their determinants in a population-based registry of young adult women with CH.

SETTING AND DESIGN

In total, 1748 subjects were diagnosed with CH in the first 10 years after the introduction of neonatal screening in France; 1158 of these subjects completed a questionnaire on fecundity at a mean age of 25.3 years. We analyzed all declared singleton pregnancies ending after greater than 22 weeks of gestation before the initial survey (n = 207 pregnancies) and in the 3 years following the initial survey (prospective study, n = 174 pregnancies). The reference group comprised 7245 subjects from the French National Perinatal Survey.

MAIN OUTCOME MEASURES

Pregnancy outcomes. Serum TSH concentrations and thyroid hormone requirements.

RESULTS

In both the overall and prospective analyses, CH was associated with gestational hypertension, emergency cesarean delivery, induced labor for vaginal delivery, and prematurity. For the prospective population with CH, the adjusted odds ratios (aOR) (95% confidence interval [CI]) were 2.19 (1.26-3.81), 1.88 (1.17-3.02), 1.58 (1.12-2.24), and 1.85 (1.06-3.25), respectively. TSH concentrations at least 10 mIU/l during the first 3 or 6 months of pregnancy were associated with a higher risk of preterm delivery (aOR, 5.6; 95% CI, 1.6-20.0) and fetal macrosomia (aOR, 4.5; 95% CI, 1.03-20.1), respectively, whereas no such relationship was observed for TSH concentrations of 5.0-9.9 mIU/l.

CONCLUSION

CH may result in adverse pregnancy outcomes. These nationwide data suggest that better thyroid disease management is required, particularly during the first two trimesters of pregnancy, together with vigilant monitoring.

Thyroid function in pregnancy and its influences on maternal and fetal outcomes

BACKGROUND

Maternal thyroid function alters during pregnancy. Inadequate adaptation to these changes results in thyroid dysfunction and pregnancy complications.

OBJECTIVES

This prospective study aimed to evaluate the prevalence of thyroid diseases in pregnancy and its outcomes in south of Iran.

MATERIALS AND METHODS

This prospective study was conducted on 600 healthy singleton pregnant women who aged 18 to 35 years old at 15 to 28 weeks of gestation. We investigated the prevalence of thyroid dysfunctions in women. Multivariate analysis was performed to determine the effect thyroid dysfunction on obstetric and neonatal outcome.

RESULTS

Thyroid stimulating hormone (TSH) levels of 0.51, 1.18, 1.68, 2.4, and 4.9 mIU/L were at 2.5th, 25th, 50th, 75th, and 97.5th percentile in our population. The prevalence of clinical hypothyroidism, subclinical hypothyroidism, overt hyperthyroidism, and subclinical hyperthyroidism in all pregnant women was 2.4%, 11.3%, 1.2%, and 0.3%, respectively. In addition, 1.4% of patients had isolated hypothyroxinemia. Clinical hypothyroidism was associated with increased risk of preterm delivery (P = 0.045). Subclinical hypothyroidism had a significant association with intrauterine growth restriction (IUGR) (P = 0.028) as well as low Apgar score at first minute (P = 0.022). Maternal hyperthyroidism was associated with IUGR (P = 0.048).

CONCLUSIONS

We revealed that thyroid dysfunction during pregnancy was associated with IUGR and low Apgar score even in subclinical forms. Further studies are required to determine whether early diagnosis and treatment of thyroid diseases, even in subclinical form, can prevent their adverse effect on fetus.

Prevalence of overt and subclinical thyroid dysfunction among pregnant women and its effect on maternal and fetal outcome

AIM

To determine the current prevalence of thyroid dysfunction in normal pregnant women and to study the impact of thyroid dysfunction on maternal and fetal outcome.

METHODS

400 pregnant women between 13 and 26 weeks of gestation were registered for the study. Apart from routine obstetrical investigations, TSH tests were done. Free T4 and anti-TPO antibody tests were done in patients with deranged TSH. Patients were followed up till delivery. Their obstetrical and perinatal outcomes were noted.

RESULTS

The prevalence of hypothyroidism and hyperthyroidism was 12 and 1.25 %, respectively. Adverse maternal effects in overt hypothyroidism included preeclampsia (16.6 vs. 7.8 %) and placental abruption (16.6 vs. 0.8 %). Subclinical hypothyroidism was associated with preeclampsia (22.3 vs. 7.8 %) as compared to the euthyroid patients. Adverse fetal outcomes in overt hypothyroidism included spontaneous abortion (16.6 vs. 2.39 %), preterm birth (33.3 vs. 5.8 %), low birth weight (50 vs. 12.11 %), intrauterine growth retardation (25 vs. 4.9 %), and fetal death (16.6 vs. 1.7 %) as compared to the euthyroid women. Adverse fetal outcomes in subclinical hypothyroidism included spontaneous abortion (5.5 vs. 2.39 %), preterm delivery (11.2 vs. 5.8 %), low birth weight (25 vs. 12.11 %), and intrauterine growth retardation (8.4 vs. 4.9 %) as compared to the euthyroid women.

CONCLUSIONS

The prevalence of thyroid disorders was high in our study with associated adverse maternal and fetal outcomes. Routine screening of thyroid dysfunction is recommended to prevent adverse fetal and maternal outcome.

Maternal thyroid function in the first twenty weeks of pregnancy and subsequent fetal and infant development: a prospective population-based cohort study in China

CONTEXT

There are a few prospective population-based cohort studies evaluating the effects of maternal thyroid dysfunctions on fetal and infant developments, but they are inconsistent.

OBJECTIVE

The objective of the study was to investigate the effects of maternal thyroid dysfunction on fetal and infant development.

SETTING AND PARTICIPANTS

The study was nested within a prospective population-based China-Anhui Birth Defects and Child Development study. A total of 1017 women with singleton pregnancies participated in this study. Maternal serum samples in the first 20 wk of pregnancy were tested for thyroid hormones (TSH and free T(4)). Pregnant women were classified by hormone status into percentile categories based on laboratory assay and were compared accordingly.

MAIN OUTCOMES

Outcomes included fetal loss, malformation, birth weight, preterm delivery, fetal stress, neonatal death, and infant development.

RESULTS

Clinical hypothyroidism was associated with increased fetal loss, low birth weight, and congenital circulation system malformations; the adjusted odds ratios [95% confidence interval (CI)] were 13.45 (2.54-71.20), 9.05 (1.01-80.90), and 10.44 (1.15-94.62), respectively. Subclinical hypothyroidism was associated with increased fetal distress, preterm delivery, poor vision development, and neurodevelopmental delay; the adjusted odds ratios (95% CI) were 3.65 (1.44-9.26), 3.32 (1.22-9.05), 5.34 (1.09-26.16), and 10.49 (1.01-119.19), respectively. Isolated hypothyroxinemia was related to fetal distress, small for gestational age, and musculoskeletal malformations; the adjusted odds ratios (95% CI) were 2.95 (1.08-8.05), 3.55 (1.01-12.83), and 9.12 (1.67-49.70), respectively. Isolated hyperthyroxinemia was associated with spontaneous abortion; the adjusted odds ratio (95% CI) was 6.02 (1.25-28.96). Clinical hyperthyroidism was associated with hearing dysplasia; the adjusted odds ratio (95% CI) was 12.14 (1.22-120.70).

CONCLUSIONS

Thyroid dysfunction in the first 20 wk of pregnancy may result in fetal loss and dysplasia and some congenital malformations.