The relation of maternal hypothyroidism and hypothyroxinemia during pregnancy on preterm birth: An updated systematic review and meta-analysis

Risk factors for preterm birth: an umbrella review of meta-analyses of observational studies

BACKGROUND

Preterm birth defined as delivery before 37 gestational weeks is a leading cause of neonatal and infant morbidity and mortality. The aim of this study is to summarize the evidence from meta-analyses of observational studies on risk factors associated with PTB, evaluate whether there are indications of biases in this literature, and identify which of the previously reported associations are supported by robust evidence.

METHODS

We searched PubMed and Scopus until February 2021, in order to identify meta-analyses examining associations between risk factors and PTB. For each meta-analysis, we estimated the summary effect size, the 95% confidence interval, the 95% prediction interval, the between-study heterogeneity, evidence of small-study effects, and evidence of excess-significance bias. Evidence was graded as robust, highly suggestive, suggestive, and weak.

RESULTS

Eighty-five eligible meta-analyses were identified, which included 1480 primary studies providing data on 166 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections, and vaccines. Ninety-nine (59.3%) associations were significant at P < 0.05, while 41 (24.7%) were significant at P < 10-6. Ninety-one (54.8%) associations had large or very large heterogeneity. Evidence for small-study effects and excess significance bias was found in 37 (22.3%) and 12 (7.2%) associations, respectively. We evaluated all associations according to prespecified criteria. Seven risk factors provided robust evidence: amphetamine exposure, isolated single umbilical artery, maternal personality disorder, sleep-disordered breathing (SDB), prior induced termination of pregnancy with vacuum aspiration (I-TOP with VA), low gestational weight gain (GWG), and interpregnancy interval (IPI) following miscarriage < 6 months.

CONCLUSIONS

The results from the synthesis of observational studies suggest that seven risk factors for PTB are supported by robust evidence. Routine screening for sleep quality and mental health is currently lacking from prenatal visits and should be introduced. This assessment can promote the development and training of prediction models using robust risk factors that could improve risk stratification and guide cost-effective preventive strategies.

TRIAL REGISTRATION

PROSPERO 2021 CRD42021227296.

Reducing the Rate of Premature Births through Early Diagnosis and Pregnancy-Adapted Treatment of Hypothyroidism

Introduction

The aim of this study was to determine the extent to which regular monitoring of maternal free thyroxine level and pregnancy-adapted L-thyroxine replacement therapy before and during pregnancy in patients with existing or newly diagnosed latent and manifest hypothyroidism as well as hypothyroxinemia can influence the rate of premature births.

Materials and Methods

This is a retrospective cohort study assessing 1440 pseudonymized survey questionnaires to evaluate the risks of premature birth with two study groups from the same medical practice, and a nationally recruited control group. Study group A (n = 360) had already been taking L-thyroxine prior to conception, study group B (n = 580) started taking it after conception. Both study groups had a maximum gestational age of 12 + 0 GW. In the study groups, TSH and free thyroxine levels were determined regularly for dose adjustment purposes. The aim was to keep the free thyroxine level in the euthyroid hyperthyroxinemic range within the pregnancy adapted reference range. The control group (n = 500) had taken L-thyroxine during pregnancy according to criteria that were not known, as the questionnaire did not include any questions regarding this matter. Taking other risk factors into account, the influence of pregnancy-adapted L-thyroxine replacement therapy on the rate of premature births was determined using logistic regression analysis.

Results

Compared with the control group, the premature birth rate was 70% lower (p < 0.0001) in study group A and 42% lower in study group B (p = 0.0086), while the odds ratio, at 3.46, was particularly significant in study group A. High blood pressure (odds ratio 5.21), body mass index per kg/m 2 (odds ratio 0.91) and S. p. premature birth were identified as other independent risk factors.

Conclusion

The results show an association between more intensive thyroid diagnostics and pregnancy-adapted L-thyroxine replacement therapy and a decrease in premature births. Further studies should be conducted to confirm these results.

Fluoride exposure and hypothyroidism in a Canadian pregnancy cohort

BACKGROUND

While fluoride can have thyroid-disrupting effects, associations between low-level fluoride exposure and thyroid conditions remain unclear, especially during pregnancy when insufficient thyroid hormones can adversely impact offspring development.

OBJECTIVES

We evaluated associations between fluoride exposure and hypothyroidism in a Canadian pregnancy cohort.

METHODS

We measured fluoride concentrations in drinking water and three dilution-corrected urine samples and estimated fluoride intake based on self-reported beverage consumption. We classified women enrolled in the Maternal-Infant Research on Environmental Chemicals Study as euthyroid (n = 1301), subclinical hypothyroid (n = 100) or primary hypothyroid (n = 107) based on their thyroid hormone levels in trimester one. We used multinomial logistic regression to estimate the association between fluoride exposure and classification of either subclinical or primary hypothyroidism and considered maternal thyroid peroxidase antibody (TPOAb) status, a marker of autoimmune hypothyroidism, as an effect modifier. In a subsample of 466 mother-child pairs, we used linear regression to explore the association between maternal hypothyroidism and child Full-Scale IQ (FSIQ) at ages 3-to-4 years and tested for effect modification by child sex.

RESULTS

A 0.5 mg/L increase in drinking water fluoride concentration was associated with a 1.65 (95 % confidence interval [CI]: 1.04, 2.60) increased odds of primary hypothyroidism. In contrast, we did not find a significant association between urinary fluoride (adjusted odds ratio [aOR]: 1.00; 95%CI: 0.73, 1.39) or fluoride intake (aOR: 1.25; 95%CI: 0.99, 1.57) and hypothyroidism. Among women with normal TPOAb levels, the risk of primary hypothyroidism increased with both increasing water fluoride and fluoride intake (aOR water fluoride concentration: 2.85; 95%CI: 1.25, 6.50; aOR fluoride intake: 1.75; 95%CI: 1.27, 2.41). Children born to women with primary hypothyroidism had lower FSIQ scores compared to children of euthyroid women, especially among boys (B coefficient: -8.42; 95 % CI: -15.33, -1.50).

DISCUSSION

Fluoride in drinking water was associated with increased risk of hypothyroidism in pregnant women. Thyroid disruption may contribute to developmental neurotoxicity of fluoride.

Association of exposure to ambient particulate matter with maternal thyroid function in early pregnancy

BACKGROUND

It is known that maternal thyroid dysfunction during early pregnancy can cause adverse pregnancy complications and birth outcomes. This study was designed to examine the association between ambient particulate matter with aerodynamic diameters ≤2.5 μm (PM2.5) and particulate matter with aerodynamic diameters ≤10 μm (PM10) exposure and maternal thyroid function during early pregnancy.

METHODS

This study was based on data from a birth cohort study of 921 pregnant women in China. We estimated associations between ambient PM2.5 and PM10 exposure during the first trimester of pregnancy (estimated with land-use regression models) and maternal thyroid hormone concentrations (free thyroxine (FT4), free tri-iodothyronine (FT3), and thyroid-stimulating hormone (TSH)) collected between weeks 10 and 17 of gestation using linear regression models adjusting for potential confounders. Ambient PM2.5 and PM10 concentrations were modeled per interquartile range (IQR) increment and as tertiles based on the distribution of the exposure levels.

RESULTS

An IQR increment (68 μg/m3) in PM2.5 exposure was associated with a significant decrease in maternal FT4 levels (β = -0.60, 95% CI: -1.07, -0.12); and a significant decrease in FT4/FT3 ratio (β = -0.13, 95% CI: -0.25, -0.02). Further analyses showed that, relative to the lowest tertile, women in both the middle and highest tertiles of PM2.5 had significantly lower concentrations of maternal FT4 and FT4/FT3 ratio. No significant associations were found between PM2.5 and FT3 or TSH levels. PM10 exposure was not significantly associated with maternal thyroid function.

CONCLUSIONS

Our study suggested that higher ambient PM2.5, not PM10, exposed during the first trimester of pregnancy were associated with a significant decrease in maternal serum FT4 concentrations and FT4/FT3 ratio. Studies in populations with different exposure levels are needed to replicate our study results.

Primary hemostasis in fetal growth restricted neonates studied via PFA-100 in cord blood samples

BACKGROUND

Platelet function of fetal growth restricted (FGR) neonates remains a field of debate. Platelet function analyzer (PFA-100) offers a quantitative in vitro assessment of primary, platelet-related hemostasis. Our aim was to examine platelet function using PFA-100 in FGR neonates and associate our results with perinatal parameters.

METHODS

PFA-100 was applied on 74 FGR neonates, 48 full-term (>37 weeks' gestation) and 26 preterm neonates (<37 weeks). The control group consisted of 118 healthy neonates. Two closure times (CTs) with COL/EPI and COL/ADP cartridges were determined on cord blood samples for each subject. Statistical analysis was performed by SAS 9.4. The statistical significance level was set at 0.05 and all tests were two-tailed.

RESULTS

COL/EPI CTs were prolonged in FGR (median 132 s, IQR 95-181 s) compared with control neonates (median 112.5 s, IQR 93-145 s), p = 0.04. Median COL/EPI CT for term and preterm FGR neonates was 126 s (IQR 90-157 s) and 137 s (IQR 104-203), respectively (p = 0.001), and COL/ADP CT was 70 s (IQR 62-80 s) for term and 75 s (IQR 68-82 s) for preterm FGR neonates (p = 0.08). Among FGR neonates, COL/EPI CT was related with delivery time (with preterm neonates exhibiting prolonged COL/EPI CTs), p = 0.05. No correlation was proved between both CTs and hematological parameters in FGR neonates.

CONCLUSION

FGR neonates showed impaired platelet function via PFA-100, with preterm FGR neonates confronting the greatest risk. Prolonged COL/EPI CTs in FGR neonates seemed to be independent of hematological parameters and could warn for closer evaluation during the first days of their lives.

Impact of TPOAb-negative maternal subclinical hypothyroidism in early pregnancy on adverse pregnancy outcomes

PURPOSE

To investigate the effect of subclinical hypothyroidism on pregnancy outcomes of women early in their pregnancy with different thyroid-stimulating hormone levels and thyroid peroxidase antibody-negative status and to explore reasonable thyroid-stimulating hormone levels for subclinical hypothyroidism in early pregnancy.

METHODS

A total of 2378 women early in their pregnancy were studied retrospectively. The baseline characteristics were collected from medical records. Pregnancy outcomes were compared between the euthyroidism and subclinical hypothyroidism groups that were diagnosed by 2011 or 2017 American Thyroid Association guidelines. In addition, the effect of different maternal thyroid-stimulating hormone levels on adverse pregnancy outcomes was analyzed using binary logistic regression.

RESULTS

According to the 2011 American Thyroid Association diagnostic criteria of subclinical hypothyroidism, the prevalence of pregnancy outcomes was not significantly higher in the subclinical hypothyroidism group than in the euthyroidism group. However, pregnant women with subclinical hypothyroidism identified by the 2017 American Thyroid Association criteria had a higher risk of premature delivery (odds ratio = 3.93; 95% confidence interval = 1.22-12.64), gestational diabetes mellitus (odds ratio = 2.69; 95% confidence interval = 1.36-5.32), and gestational anemia (odds ratio = 3.28; 95% confidence interval = 1.60-6.75). Moreover, no differences in the prevalence of adverse pregnancy outcomes were observed between the mildly elevated thyroid-stimulating hormone group (2.5 < thyroid-stimulating hormone ⩽4.0 mIU/l) and the normal thyroid-stimulating hormone group (0.27 < thyroid-stimulating hormone ⩽2.5 mIU/l). The significantly elevated thyroid-stimulating hormone group (4.0 < thyroid-stimulating hormone < 10.0 mIU/l) had a higher prevalence of premature delivery, gestational diabetes mellitus, and gestational anemia than the normal thyroid-stimulating hormone group, even after controlling for potential confounding factors.

CONCLUSION

A mildly elevated thyroid-stimulating hormone level or maternal subclinical hypothyroidism diagnosed by 2011 American Thyroid Association guidelines during early pregnancy in thyroid peroxidase antibody-negative women was not associated with adverse pregnancy outcomes. However, maternal subclinical hypothyroidism identified by the 2017 American Thyroid Association guidelines increased the risks of several adverse pregnancy outcomes in women untreated with levothyroxine. The 2017 American Thyroid Association guidelines could be more reasonable for the diagnosis of subclinical hypothyroidism in southern China.

Laboratory characteristics analysis of the efficacy of levothyroxine on subclinical hypothyroidism during pregnancy: a single-center retrospective study

To reassess the efficacy of levothyroxine on subclinical hypothyroidism (SCH, 4.0 mIU/L ≤ TSH (thyroid stimulating hormone) <10 mIU/L with normal free T4) during pregnancy. 165 levothyroxine-treated pregnant women experiencing SCH were screened. And controls were randomly selected using euthyroidism (EU) women, matched by age, gravidity, and parity in the EU group (n = 660). We evaluated laboratory characteristics and pregnancy outcomes during follow-ups. Compared with the EU group, the SCH group displayed higher inadequate maternal gestational weight gain, premature delivery, low birth weight offspring and infant offspring small for their gestational age. After levothyroxine treatment, the SCH group displayed lower total cholesterol, low-density lipoprotein levels, and higher serum homocysteine levels before delivery. Pregnant women with SCH still exhibit adverse pregnancy outcomes after levothyroxine treatment. Taken together, we believe that besides levothyroxine, vitamin B12 and folic acid could be added to the treatment of pregnant women with SCH. In addition, regular monitoring of blood sugar levels, lipid and homocysteine levels, and intervention gestational weight gain could alleviate the adverse effects of SCH on pregnancy outcomes.

Women with high plasma levels of PBDE-47 are at increased risk of preterm birth

OBJECTIVES

Nearly 100% of North American women have detectable levels of flame retardants such as polybrominated diphenyl ethers (PBDEs) in their plasma. These molecules have structural homology to thyroid hormones and may function as endocrine disruptors. Thyroid dysfunction has previously been associated with increased risk for preterm birth. Therefore, we conducted a multi-center, case-cohort study to evaluate if high plasma concentrations of a common PBDE congener in the first trimester increases the risk of preterm birth and its subtypes.

METHODS

Pregnant women were recruited at the onset of initiation of prenatal care at Kaiser-Permanente Southern California (KPSC)-West Los Angeles and KPSC-San Diego medical centers. Plasma samples from women whose pregnancies ended preterm and random subset of those delivering at term were assayed for PBDE-47 and thyroid-stimulating hormone (TSH) by immunoassay. Quartile cutoffs were calculated for the patients at term and used to determine if women with exposures in the 4th quartile are at increased risk for preterm birth using logistic regression.

RESULTS

We found that high concentrations of PBDE-47 in the first trimester significantly increased the odds of both indicated (adjusted odds ratio, adjOR=2.35, 95% confidence interval [CI]: 1.31, 4.21) and spontaneous (adjOR=1.76, 95% CI: 1.02, 3.03) preterm birth. Regardless of pregnancy outcome, TSH concentrations did not differ between women with high and low concentrations of PBDE-47.

CONCLUSIONS

These results suggest that high plasma concentrations of PBDE-47 in the first trimester, increases the risk of indicated and spontaneous preterm birth.

The Association Between Isolated Maternal Hypothyroxinemia in Early Pregnancy and Preterm Birth

Background: The association between isolated maternal hypothyroxinemia (IMH) during pregnancy and preterm birth (PTB), especially for subtypes of PTB, is unclear. This study aimed at determining the association between IMH diagnosed in early pregnancy and PTB, with further investigation into various subtypes of PTB. Methods: This study included 41,911 pregnant women (963 with IMH and 40,948 euthyroid women) who underwent first-trimester prenatal screening at the International Peace Maternity and Child Health Hospital (IPMCH) in Shanghai, China between January 2013 and December 2016. PTB was defined as birth before 37 weeks of gestation. PTB was further classified into three clinically relevant groups to investigate the clinical heterogeneity of PTB: (a) preterm birth with premature rupture of membranes (PROM-PTB); (b) spontaneous preterm birth with intact membranes (S-PTB); and (c) medically-induced preterm birth (MI-PTB). The overall and sex-specific effect of IMH on PTB and various subtypes of PTB were estimated by using logistic regression in crude and adjusted models. Results: Pregnant women with IMH had an increased risk of PTB (odds ratio [OR]: 1.32 [95% confidence interval; CI: 1.02-1.70], p = 0.03) compared with women with euthyroid function. The increased risk of PTB is mainly driven by S-PTB (OR: 1.57 [CI: 1.11-2.24], p = 0.01), while women with early pregnancy IMH had no statistically significant increased risk of PROM-PTB and MI-PTB. The effect of IMH on PTB was modified by fetal sex (p-values for interaction = 0.04). More prominent effects were observed in women carrying a female fetus, while no statistically significant effects were found in women carrying a male fetus. Conclusions: This study revealed that pregnant women with IMH in early pregnancy have a higher risk of PTB compared with euthyroid women. The effect of IMH on PTB is mainly driven by S-PTB and is modified by fetal sex.

Causes of mortality in a neonatal intensive care unit in Iran: one year data

BACKGROUND Neonatal mortality rate is a major health index. Approximately, 65% of all deaths in the first year of life occur during this 4-week period. The present study was conducted to investigate the mortality rates and causes of death in a neonatal intensive care unit (NICU) in Ahvaz, Iran in a year.  METHODS This cross-sectional study was conducted in the NICU of Sina Hospital in Ahvaz. Medical records were studied, and data from 1,040 newborns admitted to the NICU within one year (March 2016 to March 2017) were collected following a checklist. Of these newborns, 123 died, and their relevant data were collected. Data were analyzed using SPSS, version 20 (SPSS Inc., USA).  RESULTS The mortality rate was 11.82% (123 cases) out of 1,040 newborns admitted to NICU. Most of the newborns (48.8%) died on days 1–7. The causes of death were respiratory distress syndrome (RDS) (34.1%), asphyxia (25.2%), anomalies (10.6%), sepsis (7.3%), intracerebral hemorrhage (8.1%), pulmonary hemorrhage (7.3%), and other causes (6.4%), such as hydrops, severe pneumothorax, severe renal failure, and others.  CONCLUSIONS The mortality rate in the NICU of this center was similar to that in other Iranian provinces. The most common causes of NICU mortality included prematurity and its complications, such as asphyxia and RDS. Thus, a strategic plan for reducing preterm delivery and asphyxia are necessary.

Epidemiology of low birth weight in Iran: A systematic review and meta-analysis

Introduction

Low birth weight (LBW) is an important general health indicator. The present study was conducted to evaluate the prevalence and risk factors of LBW in Iran.

Method

This meta-analysis was reported based on the PRISMA guidelines. All stages were independently performed by two authors. This review is registered with PROSPERO (CRD42020163446). We searched epidemiological studies at international databases of Scopus, Embase, Science Direct, PubMed/Medline, CINAHL, EBSCO, Cochrane Library, Web of Science, and Google Scholar search engine, as well as Iranian databases of SID, IranDoc, Iranian National Library, Barakat Knowledge Network System, RICST and Magiran using MeSH keywords without time limit until 2019. After selecting the studies, applying the inclusion and exclusion criteria, data extraction and qualitative assessment, the data were analyzed based on random effects model using Comprehensive Meta-Analysis Software version 2. P < 0.05 was considered significant.

Results

The prevalence of LBW in Iran was 7.95% (95% confidence interval [CI]: 7.36-8.58) in 62 studies with a sample size of 301,839 newborns. The prevalence of LBW in girls and boys was 8.41% (95%CI: 7.47-9.45) and 6.67% (95%CI: 5.86-7.59), respectively. The girls-to-boys odds ratio of LBW was 1.25 (95%CI: 1.13-1.39, P < 0.001) very LBW and extremely LBW prevalence was estimated to be 0.61% (95%CI: 0.40-0.93) and 0.29% (95% CI: 0.18-0.45), respectively. The risk factors for LBW were age of >35 versus [vs.] ≤35 (P = 0.024), age of <18 vs. ≥18 (P < 0.001), education of middle school and lower vs. high school and higher (P < 0.001), weight under 50 kg (P = 0.001), employed vs. housekeeper (P < 0.001), inadequate prenatal care (P = 0.046), interval with previous pregnancy <2 vs. >2 (P < 0.001), prematurity (P < 0.001), history of LBW (P < 0.001), multiple birth (P < 0.001), abortion (P < 0.001), vaginal bleeding (P < 0.001), hypertension (P = 0.001) and preeclampsia (P < 0.001).

Conclusion

The results of this meta-analysis showed that LBW is prevalent in Iran. This study can be a national database for LBW that would be of interest to Iranian health policy-makers and planners.

The effect of Islamic semanticism on self-reporting and lifestyles of mothers of adolescents with thalassemia

BACKGROUND

Thalassemia is the most common chronic hereditary disease in the world.

OBJECTIVES

The purpose of this study was to determine the effect of logotherapy on the level of resilience of mothers of children with thalassemia major.

METHODS

The statistical population of this study included all mothers with children with thalassemia major in Gonbad-e-Qabus. After selecting eligible samples, each sample was given a number and the number was put into a non-transparent envelope. The samples were assured that numbering and placement in one of two groups were completely random and 60 mothers were selected using available sampling. The research tool used was the Kollahen Brief Self-reporting Questionnaire. For the experimental group, eight sessions of 90 min of logotherapy training were performed. For both groups, pre-test and post-test were performed. The confidentiality of the data of the research samples was assured. Data were gathered. Finally, the information was analyzed using SPSS software version 16.

RESULTS

The results showed that the mean of the resilience of the experimental group was 28/16 ± 8/63 in the pre-test to was 24/76 ± 6/4 in the post-test. The result of paired t-test analysis showed that after eliminating the effect of the pre-test, the mean scores of the post-test of the two groups were statistically significant (p < 0/01, t = 18/4).

CONCLUSION

This study shows that logotherapy for mothers with children with thalassemia is useful and it is effective in increasing the resilience of mothers.

Slightly elevated thyrotropin levels in pregnancy in our clinical practice

OBJECTIVE

The aim of this study was to assess the incidence of obstetric and neonatal complications in pregnant women with "normal" thyroid-stimulating hormone (TSH) levels in the first trimester (group A) and to compare them with those with "slightly elevated" TSH (SET) levels treated with levothyroxine (group B2) or not treated (group B1).

METHODS

A total of 2375 women who had been performed laboratory tests in their first trimester of pregnancy were detected at our hospital between April 2015 and August 2017. Of these, 469 patients with SET were prospectively detected and randomized to groups B1 (227) and B2 (242). They were monitored prospectively until 6 months after delivery. Data of the control group (n=1906, group A) were retrospectively reviewed. A total of 1745 women were analyzed. Variables assessed included demographic and clinical characteristics and complications of pregnancy and delivery.

RESULTS

A, B1, and B2 had similar clinical characteristics. There were no statistically significant differences in complications between the three groups during pregnancy, except in that natural deliveries were more common in group A as compared to group B1 (76.8% vs. 68.7%, p 0.017) and group B2 (66.3%), p<0.002). There were more induced deliveries in groups B1 (35.8%), and B2 (36.2%) than in group A (18.4%), p<0.01. Although the recommended TSH level was achieved in the second and third trimesters, no benefit could be found of treatment of SET.

CONCLUSION

Although there were less natural deliveries and more induced deliveries in patients with SET, treatment with levothyroxine could not reverse this situation, despite achievement of levels considered appropriate in the second and third trimester.

The effect of positive thinking training on the quality of life of parents of adolescent with thalassemia

Introduction Thalassemia, as the most common chronic hereditary blood disorder in humans, can impose many adverse effects on parents and their affected children. On the other hand, positive thinking is the method or the result of a positive focus on a constructive issue, so by teaching positive thinking, we can improve physical and social function, and promote emotional health and overall quality of life. The aim of this study was to determine the effect of positive thinking training on the quality of life of parents of adolescents with thalassemia. Methods This quasi-experimental study was performed on 52 parents of adolescents with thalassemia who attended Taleghani Hospital in Golestan province, Iran in 2017. Samples were randomly assigned into two groups of intervention and control. The positive thinking training (based on the theory of Martin Seligman) was carried out in the intervention group in 10 (45-60 min) sessions over a 5-week period. Data collection tools in this study were the World Health Organization (WHO) quality of life questionnaire (WHOQOL-BREF) and a demographic information questionnaire. Data were analyzed by SPSS-16 software using independent t-test, the paired t-test and a covariance test. Results The results of paired t-test showed a significant difference in the score of quality of life in intervention group before and after the intervention (p < 0.001). However, this test did not show any significant difference in the control group (p = 0.11). The covariance test, after removing the pre-test score, showed a significant difference between the intervention and control groups in terms of the score of quality of life, so that 13% of the changes after the intervention were due to the intervention (p = 0.009, η = 0.13). Conclusion The positive thinking training increased the quality of life of parents of adolescents with thalassemia. Therefore, using this program can be an effective way of improving the quality of life of parents. Thus, positive thinking training is suggested to be used as an effective strategy for increasing the quality of life of parents with ill children.

Levothyroxine treatment and pregnancy outcomes in women with subclinical hypothyroidism: a systematic review and meta-analysis

PURPOSE

To evaluate the benefits of LT4 treatment on pregnancy outcomes in SCH women.

STUDY DESIGN

PubMed [including Medline], Web of Science, Wiley, Google Scholar, Science direct and Scopus were searched for identifying and retrieving all English articles published up to May 2018 on the effects of levothyroxine treatment on pregnancy outcomes in pregnant women with SCH compared to untreated or healthy controls. In this systematic review and meta-analysis, both fixed and random effect models were applied to estimate the pooled effect size. Heterogeneity and publication bias were evaluated using the I-squared (I²) and Begg's statistics, respectively. We also explored heterogeneity sources using meta-regression models and sensitivity analysis.

RESULTS

Data of 13 cohort studies and randomized controlled trials with a total of 11,503 participants were analyzed. This meta-analysis showed that pregnant women with SCH treated with levothyroxine had lower chances of pregnancy loss (OR 0.78, 95% CI 0.66-0.94; I² = 0%) and higher chances for live birth rates (OR 2.72, 95% CI 1.44-5.11; I² = 25%) than the placebo group. Compared to euthyroid women, SCH patients treated with levothyroxine had higher odds ratio for preterm labor (OR 1.82, 95% CI 1.14-2.91; I² = 0%).

CONCLUSIONS

Results of this study showed that the effects of treatment with levothyroxine in SCH pregnant women are not the same for all pregnancy outcomes. Levothyroxine treatment in these patients can reduce pregnancy loss. Considering the limited number of studies available, further studies are warranted to document more precise data on other consequences.