Clinical aspects of hyperthyroidism, hypothyroidism, and thyroid screening in pregnancy

Australasian Recurrent Pregnancy Loss Clinical Management Guideline 2024 Part I

Guidelines for the investigation and management of recurrent pregnancy loss (RPL) have been developed in Europe, USA and UK, but there is currently no Australasian guideline. The Australasian Certificate of Reproductive Endocrinology and Infertility Consensus Expert Panel on Trial Evidence group has prepared a two-part guideline to provide guidance on the management of RPL. In Part I chromosomal, anatomical, and endocrine factors are outlined along with relevant recommendations for clinical management, levels of evidence and grades of consensus. In Part II thrombophilia, autoimmune factors, infective, inflammatory, and endometrial causes, environmental and lifestyle factors, male factor and unexplained causes will be outlined.

Omega-3 fatty acid supplements and recurrent miscarriage: A perspective on potential mechanisms and clinical evidence

Recurrent miscarriage (RM) affects approximately 1%-5% of couples worldwide. Due to its complicated etiologies, the treatments for RM also vary greatly, including surgery for anatomic factors such as septate uterus and uterine adhesions, thyroid modulation drugs for hyperthyroidism and hypothyroidism, and aspirin and low molecular weight heparin for antiphospholipid syndrome. However, these treatment modalities are still insufficient to solve RM. Omega-3 fatty acids are reported to modulate the dysregulation of immune cells, oxidative stress, endocrine disorders, inflammation, etc., which are closely associated with the pathogenesis of RM. However, there is a lack of a systematic description of the involvement of omega-3 fatty acids in treating RM, and the underlying mechanisms are also not clear. In this review, we sought to determine the potential mechanisms that are highly associated with the pathogenesis of RM and the regulation of omega-3 fatty acids on these mechanisms. In addition, we also highlighted the direct and indirect clinical evidence of omega-3 fatty acid supplements to treat RM, which might encourage the application of omega-3 fatty acids to treat RM, thus improving pregnancy outcomes.

Recurrent Pregnancy Loss Etiology, Risk Factors, Diagnosis, and Management. Fresh Look into a Full Box

Recurrent pregnancy loss is a complex health challenge with no universally accepted definition. Inconsistency in definitions involves not only the number of spontaneous abortions (two or three) that are accepted for recurrent pregnancy loss but the types of pregnancy and gestational age at miscarriage. Due to the heterogeneity of definitions and criteria applied by international guidelines for recurrent pregnancy loss, the true incidence of recurrent miscarriage, which is reported to range from 1% to 5%, is difficult to estimate. Moreover, the exact etiology of recurrent pregnancy loss remains questionable; thus, it is considered a polyetiological and multifactorial condition with many modifiable and non-modifiable factors involved. Even after thoroughly evaluating recurrent pregnancy loss etiology and risk factors, up to 75% of cases remain unexplained. This review aimed to summarize and critically analyze accumulated knowledge on the etiology, risk factors, relevant diagnostic options, and management approach to recurrent pregnancy loss. The relevance of various factors and their proposed roles in recurrent pregnancy loss pathogenesis remains a matter of discussion. The diagnostic approach and the management largely depend on the etiology and risk factors taken into consideration by a healthcare professional as a cause of recurrent miscarriage for a particular woman or couple. Underestimation of social and health consequences of recurrent pregnancy loss leads to compromised reproductive health and psychological well-being of women after miscarriage. Studies on etiology and risk factors for recurrent pregnancy loss, especially idiopathic, should be continued. The existing international guidelines require updates to assist clinical practice.

Management of Hyperthyroidism during Pregnancy: A Systematic Literature Review

In pregnancy, several physiological changes affect maternal circulating thyroid hormone levels. The most common causes of hyperthyroidism in pregnancy are Graves' disease and hCG-mediated hyperthyroidism. Therefore, evaluating and managing thyroid dysfunction in women during pregnancy should ensure favorable maternal and fetal outcomes. Currently, there is no consensus regarding an optimal method to treat hyperthyroidism in pregnancy. The term "hyperthyroidism in pregnancy" was searched in the PubMed and Google Scholar databases to identify relevant articles published between 1 January 2010 and 31 December 2021. All of the resulting abstracts that met the inclusion period were evaluated. Antithyroid drugs are the main therapeutic form administered in pregnant women. Treatment initiation aims to achieve a subclinical hyperthyroidism state, and a multidisciplinary approach can facilitate this process. Other treatment options, such as radioactive iodine therapy, are contraindicated during pregnancy, and thyroidectomy should be limited to severe non-responsive thyroid dysfunction pregnant patients. In light of this events, even in the absence of guidelines certifying screening, it is recommended that all pregnant and childbearing women should be screened for thyroid conditions.

Methimazole-induced gestational hypothyroidism affects the offspring development and differently impairs the conditioned fear in male and female adulthood rodents

Gestational hypothyroidism is a prevalent disorder in pregnant women and also impairs fetal development with relevant outcomes. One of the outcomes of greatest interest has been rodent fear- and anxiety-like behavior. However, the relationship between maternal hypothyroidism and onset of conditioned fear-related responses in offspring remains controversial. Here, we used a well-validated methimazole-induced gestational hypothyroidism to investigate the behavioral consequences in offspring. Dams were treated with methimazole at 0.02% in drinking water up to gestational Day 9. Maternal body weights and maternal behavior were evaluated, and the puppies ware analyzed for weight gain and physical/behavioral development and assigned for the open field and fear conditioning test. Methimazole-induced gestational hypothyroidism induced loss in maternal and litter weight, increases in maternal behavior, and impairs in offspring developmental landmarks in both male and female rodents. Only male offspring enhanced responsiveness to conditioned fear-like behavior in adulthood.

Thyroid dysfunction in pregnancy - a retrospective observational analysis of a Maltese cohort

BACKGROUND

Thyroid dysfunction is known to adversely affect pregnancy. This study evaluates the prevalence of thyroid disorders and explores their association with pregnancy complications/comorbidities and modes of delivery in the Maltese pregnant population over a ten year period.

DESIGN

A population based observational study.

METHOD

We analysed data from the National Obstetrics Information Service of the Department of Health Informations and Research (NOIS) for all births delivered in Malta between 2006 and 2016. Cases identified and recorded by NOIS to have had some form of thyroid dysfunction during pregnancy were confirmed by cross-referencing  with laboratory results found in patients' medical records and/or iSOFT® database system. Using the Statistical Package for the Social sciences (SPSS®)  demographic data, past obstetric and medical history and obstetric outcomes were analysed for pregnancies with thyroid dysfunction and compared to data pertaining to pregnancies in euthyroid patients, that is those with no recorded thyroid dysfunction on NOIS. Chi square/Fisher's exact test were used to compare categorical variables while ANOVA/Mann-Whitney U test was used to compare continuous variables. Statistical significance was defined by a two-sided p value <0.05.

RESULTS

Data was available for 46,283 women (mean [SD] age = 29.2 [5.4] years). 587 pregnancies (1.3%) suffered from thyroid dysfunction. Of these, 67.3% were hypothyroid, 3.2% had hyperthyroidism, 28.3% had isolated hypothyroxinaemia (IHT) while 1.2% had a history of thyroid carcinoma. Patients with IHT and hypothyroidism were older than euthyroid patients (p < 0.001).  IHT and hypothyroid patients had a statistically significant higher body mass index (BMI) than euthyroid women (p=0.001 for hypothyroid women, p = 0.035 for IHT). Hypothyroid  and IHT women were more likely to have had a previous lower segment caesarean section  (p=0.043,  and 0.006 respectively). Type 1 diabetes and gestational diabetes  p = 0.012) were more common associated comorbidities in hypothyroid pregnancies. Offspring of patients with IHT had a higher birth weight than those born to euthyroid patients (p=0.009). Patients with hyperthyroidism were found to have a significantly increased risk of early preterm delivery before 34 weeks of gestation and were also more likely to have suspected intrauterine growth restriction and low mean birth weight. We report no significant differences in past history of obstetric loss, antenatal complications, mode of delivery, gestational age at delivery and postpartum haemorrhage rates across thyroid categories.

CONCLUSIONS

Available evidence suggests that thyroid dysfunction is more likely in the setting of older age, and higher body mass index. Moreover, it impacts on neonatal birth weight, rates of early preterm delivery and intrauterine growth restriction.

Multisensory Stimulation Improves Cognition and Behavior in Adult Male Rats Born to LT4-treated Thyroidectomized Dams

Gestational hypothyroidism can impair development, cognition, and mood. Here, we tested whether multisensory stimulation (MS) improves the phenotype of rats born to surgically thyroidectomized (Tx) dams suboptimally treated with LT4. 8-week-old female Tx Wistar rats were kept on daily LT4 (0.7 µg/100 g body weight) dosed by gavage (serum TSH and T4 levels indicated moderate hypothyroidism) and 3 weeks later placed for breeding. MS of the litter started at age 60 days and lasted for 8 weeks. It consisted of twice per week of physical, cognitive, sensorial, and food stimuli. The offspring were assessed before and after MS for standardized tests of locomotor activity, cognition, and mood. Gestational hypothyroidism resulted in reduced litter size and increased offspring mortality. The pups exhibited delayed physical development, impairment of short- and long-term memory, and anxiety- and depressive-like behaviors. Nonetheless, ambulatory activity, social memory, and social preference were not affected by gestational hypothyroidism. MS restored short-term memory and anxiety while improving depressive like-behaviors. MS did not improve long-term memory. MS also did not modify the performance of control litter born to intact dams. We conclude that cognition and mood impairments caused by moderate gestational hypothyroidism were reversed or minimized in rats through MS. Further studies should define the molecular mechanisms involved.

Indications for intensive care unit treatment among neonates born to mothers with thyroid disease: A population-based cohort study

INTRODUCTION

Thyroid diseases in pregnancy are relatively common and are associated with adverse pregnancy and perinatal outcomes, increasing a neonate's risk of admission to the neonatal intensive care unit (NICU). The aim of this study was to evaluate the indications for increased risk of NICU admission among the neonates of hypothyroid and hyperthyroid mothers.

MATERIAL AND METHODS

The study data consisted of all singleton deliveries (n = 734 773) between 2004 and 2016 in Finland collected from the Finnish Medical Birth Register. The odds of NICU admission (with 95% confidence intervals) were compared between the neonates of hypothyroid or hyperthyroid mothers and of mothers without any thyroid diseases by specified neonatal characteristics and morbidities using logistic regression analysis. The studied neonatal characteristics were preterm birth (<37+0 gestational weeks), low birthweight (<2500 g), the rate of small- and large-for-gestational age infants, and eight disease-specific neonatal outcomes: asphyxia, respiratory distress syndrome, meconium aspiration syndrome, pneumothorax, cardiovascular problems, infections, jaundice and hypoglycemia.

RESULTS

The most common indications for NICU care were principally the same in the neonates of the mothers with and without thyroid disease: respiratory distress syndrome, infections, preterm birth, low birthweight and neonatal hypoglycemia. The preterm neonates, neonates with low birthweight, and large-for-gestational-age infants had increased odds of NICU admission if their mother had hypothyroidism. Also neonates with cardiovascular problems, jaundice or hypoglycemia associated with maternal diabetes had increased odds of NICU admissions if their mother had hypothyroidism. Further, the preterm neonates, large-for-gestational-age infants, and term infants with jaundice had increased odds of NICU admission if their mother had hyperthyroidism.

CONCLUSIONS

The most common indications for NICU care were similar for the neonates of the mothers with and without thyroid disease. However, the neonates of the mothers with thyroid diseases were more likely to need NICU care. The neonates of the mothers with thyroid diseases had higher odds of NICU treatment in cases of preterm birth, large for gestational age, and hypoglycemia.

Hyperthyroidism management during pregnancy and lactation (Review)

Thyroid dysfunction is a significant public health issue, affecting 5-10 more women compared to men. The estimated incidence is up to 12% and only for women the treatment rises up to 4.3 billion dollars annually. Thyroid pathology can have a major impact on female fertility and it can only be detected when preconception tests are performed. Untreated or poorly treated hyperthyroidism in a mother can affect the fetal development and pregnancy outcome. Between 0.1 and 0.4% of the pregnancies are affected by clinical hyperthyroidism. Thyroid dysfunction is associated with higher rates of pregnancy loss. Hyperthyroidism can complicate fetal health problems intrauterinely and in the neonatal period. The TSH receptor is stimulated by TSH and HCG which has a similar structure. This can lead to gestational thyrotoxicosis. Hyperthyroidism can be treated with propylthiouracil or methimazole and in selected cases, surgical treatment or radioactive iodine can be chosen. In pregnancy, the most used treatment is represented by propylthiouracil which can be used from the first trimester. The aim of this review is to assess the current data regarding the impact of thyroid dysfunction on pregnancy and to synthesize the treatment options during pregnancy and lactation.

The Increased Trend of Medical Treatment for Thyroid Diseases during Pregnancy: A 13-Year National Study

OBJECTIVE

Thyroid dysfunction affects up to 5-7% of all pregnancies. The rates of thyroid hormone use in nonpregnant population have substantially increased in recent years. The aim of this study was to assess possible changes in the use of levothyroxine substitution and antithyroid drugs over time in pregnant women.

METHODS

The study data consisted of all singleton pregnancies (N = 736,873) between 2004 and 2016 in Finland collected from the Finnish Medical Birth Register. The Prescription Register and Special Refund Entitlement Register provided information on levothyroxine and antithyroid drug purchases. The annual rates of levothyroxine and antithyroid drug prescription redemptions were explored to estimate changes in exposure rates to thyroid medication from 2004 to 2016. Joinpoint regression analyses were performed to explore interannual variability in levothyroxine and antithyroid drug treatment.

RESULTS

There was more than a five-fold increase in levothyroxine use during the study period; in 2004, 1.1% of pregnant women had levothyroxine treatment, and by 2016, the prevalence increased to 6.2%. In addition, we observed a slight increase in antithyroid medication during pregnancy, but antithyroid drug use during pregnancy overall was very rare. In 2004, 0.05% of pregnant women used antithyroid drugs, and by 2016, this percentage had increased to 0.14%.

CONCLUSIONS

Our study shows that the rate of levothyroxine use in pregnancy has markedly increased. This suggests that tracing and screening relevant patients and awareness of thyroid disorders on pregnancy and their significance for the pregnancy outcome have increased and the threshold to treat thyroid disorders has declined.

Subclinical thyroid diseases and isolated hypothyroxinemia during pregnancy

Thyroid diseases in pregnancy are common. While data on management of overt diseases are clear, there is no consensus regarding subclinical thyroid disease. Many studies have tried to clarify the impact of subclinical thyroid disease on pregnancy outcomes without reaching universal conclusions. As several studies are present in literature, but no univocal indication is present to manage each condition, the present review tries to summarize the recent indications for such disease. The most updated guidelines are 2017 American thyroid association for thyroid disease during pregnancy, which at present represent the most accurate and reliable guide. Subclinical hyperthyroidism during pregnancy has not been associated with adverse outcomes and only needs follow up. Subclinical hypothyroidism is associated with adverse obstetric and offspring outcomes. At present thyroxine treatment is recommended in selected cases, as beneficial effects are not clear for all these patients. Data regarding the association between isolated hypothyroxinemia and adverse maternofetal outcome are controversial but treatment is not indicated. Autoimmune thyroid disease represents the main thyroid risk factor for adverse pregnancy outcomes. If patients have normal TSH values, treatment is not indicated. A possible thyroxine treatment can be evaluated on a case-by-case basis in euthyroid patients with history of abortion/infertility. In the last years, risks of subclinical thyroid dysfunction on the outcome of gestation and new-born have been scaled back. Further prospective studies are necessary to better understand thyroid dysfunction in pregnancy to perfectly target treatment in appropriate settings.

Effect of the Cut-Off Level for Thyroid-Stimulating Hormone on the Prevalence of Subclinical Hypothyroidism among Infertile Mexican Women

The primary aim of this study was to compare the prevalence of subclinical hypothyroidism (SCH) using two different cut-off levels for TSH values (≥2.5 mIU/L versus ≥4.1 mIU/L). The secondary objective was to analyze the clinical-biochemical characteristics in women with and without SCH. This was a retrospective cross-sectional study. In total, 1496 Mexican women with infertility were included: Group 1, women with TSH levels ranging between 0.3 and 2.49 mIU/L, n = 886; Group 2, women with TSH between 2.5 and 4.09 mIU/L, n = 390; and Group 3, women with TSH ≥4.1 mIU/L n = 220. SCH prevalence was 40.7% (CI 95%: 38.3-43.3%) with TSH cut-off ≥ 2.5 mIU/L, and 14.7% (CI 95%: 12.7-16.5%) with TSH cut-off ≥ 4.1 mIU/L, (p = 0.0001). The prevalence of overweight was higher in Group 2 than in Groups 1 and 3. Thyroid autoimmunity, obesity and insulin resistance were higher in Group 3 than in Group 1 (p < 0.05). No other differences were observed between groups. Conclusions: The prevalence of SCH in our selected patients increased almost three times using a TSH cut-off ≥ 2.5 mIU/L compared with a TSH cut-off ≥ 4.1 mIU/L. Women with TSH ≥4.1 mIU/L compared with TSH cut-off ≤ 2.5 mIU/L more often presented with obesity, thyroid autoimmunity and insulin resistance.

Maternal hyperthyroidism and pregnancy outcomes: A population-based cohort study

OBJECTIVE

Maternal hyperthyroidism and antithyroid medications have been associated with adverse pregnancy and perinatal outcomes. This nationwide register-based study investigated the association of maternal hyperthyroidism and antithyroid drug (ATD) use with pregnancy outcomes and included all singleton births in Finland between 2004 and 2013 (N = 571 785).

DESIGN, PATIENTS AND MEASUREMENTS

Hyperthyroid mothers were identified in the Medical Birth Register, and data on ATD use before and/or during pregnancy were collected from the Prescription Register. The odds ratios, with 95% confidence intervals, for adverse outcomes among hyperthyroid mothers and mothers without thyroid disease were compared using logistic regression.

RESULTS

In total, 2144 (0.37%) of all the women had diagnoses of hyperthyroidism, and 580 (27%) of these women had used ATDs before and/or during pregnancy. Compared to the mothers without thyroid disease, maternal hyperthyroidism was associated with older age, multiparity, smoking, previous miscarriages, and overweight or obesity. The mothers diagnosed with hyperthyroidism also had increased odds of gestational hypertensive disorders, caesarean sections, placental abruptions, preterm births, small-for-gestational-age newborns and neonatal intensive care unit treatment. The odds of pregnancy and/or perinatal complications were higher among those who had used ATDs (indicative of active disease), but those who had not received ATD treatment also had increased odds of such complications compared to the mothers without thyroid disease.

CONCLUSIONS

Women with active hyperthyroidism and those with histories of hyperthyroidism should be considered at risk of developing pregnancy and perinatal complications and should therefore be monitored during pregnancy.

Clinical and subclinical maternal hypothyroidism and their effects on neurodevelopment, behavior and cognition

Clinical and subclinical hypothyroidism are the most common hormonal dysfunctions during pregnancy. Insufficient maternal thyroid hormones (THs) in the early stages of pregnancy can lead to severe impairments in the development of the central nervous system because THs are critical to central nervous system development. In the fetus and after birth, THs participate in neurogenic processes, cell differentiation, neuronal activation, axonal growth, dendritic arborization, synaptogenesis and myelination. Although treatment is simple and effective, approximately 30% of pregnant women in Brazil with access to prenatal care have their first consultation after the first trimester of pregnancy, and any delay in diagnosis and resulting treatment delay may lead to cognitive impairment in children. This review summarizes the effects of clinical and subclinical hypothyroidism on fetal neurodevelopment, behavior and cognition in humans and rodents. Arch Endocrinol Metab. 2020;64(1):89-95.

Detection of non-criteria autoantibodies in women without apparent causes for pregnancy loss

Background

Some of the non‐criteria autoantibodies, especially non‐conventional antiphospholipid (aPL) antibodies, were present with high prevalence in sporadic miscarriages and recurrent pregnant loss. However, whether these autoantibodies are associated with miscarriage patients without apparent causes remain unclear.

Methods

The subjects were recruited from the female patients visiting the Infertility Center at the Beijing Obstetrics and Gynecology Hospital from January 2017 to March 2018. The women who experienced one sporadic miscarriage (n = 89) or recurrent pregnancy loss (n = 125) were enrolled. The control participants (n = 59) were those women with normal pregnancy history and with no miscarriage or thrombosis experience. The collected serum specimens from above patients and controls were subjected to the 13 non‐criteria autoantibody examinations, targeting non‐conventional phospholipids, thyroid, sperm, endometrial, and anti‐nuclear antigens.

Results

When compared with the controls, the following non‐criteria antibodies stood out in present study with significantly increased frequency and were listed in the order of decreasing positive rates: aPE IgM (40.0%), ANA (15.2%), aEM IgG (13.6%), aPE IgG (12.8%), and aPT IgM (10.4%). Except for ANA, the presence of aPE IgM, aEM IgG, aPE IgG, and aPT IgM was not associated with positivity of LA tests. In receiver operating characteristic analyses, the combined aPE IgG and aEM IgG biomarker panel had the best discriminating power between miscarriage patients and healthy controls.

Conclusion

Our findings suggested that the non‐criteria could be included as part of the pregnancy loss evaluation when apparent causes are absent, and the conventional aPLs tests failed to provide interpretations.

An insight into the role of the death receptor CD95 throughout pregnancy: Guardian, facilitator, or foe

The prototype death receptor CD95 (Fas) and its ligand, CD95L (FasL), have been thoroughly studied due to their role in immune homeostasis and elimination of infected and transformed cells. The fact that CD95 is present in female reproductive cells and modulated during embryogenesis and pregnancy has raised interest in its role in immune tolerance to the fetoplacental unit. CD95 has been shown to be critical for proper embryonic formation and survival. Moreover, altered expression of CD95 or its ligand causes autoimmunity and has also been directly involved in recurrent pregnancy losses and pregnancy disorders. The objective of this review is to summarize studies that evaluate the mechanisms involved in the activation of CD95 to provide an updated global view of its effect on the regulation of the maternal immune system. Modulation of the CD95 system components may be the immune basis of several common pregnancy disorders.

Hypothyroidism during pregnancy and its association to perinatal and obstetric morbidity: a review

There is currently no consensus among the different scientific societies on screening for thyroid dysfunction in the first trimester of pregnancy. Indeed, diagnosis and treatment of subclinical hypothyroidism during pregnancy are controversial, as no cut-off value for thyrotropin (TSH) is universally accepted. TSH measurement may be influenced by different factors throughout pregnancy, but especially during the first trimester. The association between overt hypothyroidism during pregnancy and obstetric and perinatal complications is well established. It is also accepted that thyroid hormones are important for neurodevelopment of the offspring. However, there is no scientific evidence available about the impact of subclinical hypothyroidism and its treatment during the first trimester of pregnancy on children's neurodevelopment. In recent years, studies conducted in the offspring of mothers with subclinical hypothyroidism have reported new biochemical parameters which may eventually serve as biomarkers of offspring neurodevelopment and which are more reproducible and are measured at an earlier time than the conventional clinical tests.

Gestational Age-specific Cut-off Values Are Needed for Diagnosis of Subclinical Hypothyroidism in Early Pregnancy

During the first trimester of pregnancy, thyroid-stimulating hormone (TSH) >2.5 mIU/L has been suggested as the universal criterion for subclinical hypothyroidism. However, TSH levels change continuously during pregnancy, even in the first trimester. Therefore the use of a fixed cut-off value for TSH may result in a different diagnosis rate of subclinical hypothyroidism according to gestational age. The objective of this study was to obtain the normal reference range of TSH during the first trimester in Korean gravida and to determine the diagnosis rate of subclinical hypothyroidism using the fixed cut-off value (TSH >2.5 mIU/L). The study population consisted of pregnant women who were measured for TSH during the first trimester of pregnancy (n=492) and nonpregnant women (n=984). Median concentration of TSH in pregnant women was lower than in non-pregnant women. There was a continuous decrease of median TSH concentration during the first trimester of pregnancy (median TSH concentration: 1.82 mIU/L for 3+0 to 6+6 weeks; 1.53 mIU/L for 7+0 to 7+6 weeks; and 1.05 mIU/L for 8+0 to 13+6 weeks). Using the fixed cut-off value of TSH >2.5 mIU/L, the diagnosis rate of subclinical hypothyroidism decreased significantly according to the gestational age (GA) at TSH (25% in 3+0 to 6+6 weeks, 13% in 7+0 to 7+6 weeks, and 9% for 8+0 to 13+6 weeks, P<0.001), whereas the diagnosis rate was 5% in all GA with the use of a GA-specific cut-off value (P=0.995). Therefore, GA-specific criteria might be more appropriate for the diagnosis of subclinical hypothyroidism.

Should All Women Be Screened for Thyroid Dysfunction in Pregnancy?

The subject of universal thyroid screening in pregnancy generates impassioned debate. Thyroid dysfunction is common, has significant adverse implications for fetal and maternal well-being, is readily detectable and can be effectively and inexpensively treated. Furthermore, the currently recommended case-finding strategy does not identify a substantially proportion of women with thyroid dysfunction thus favoring universal screening. On the other hand subclinical thyroid dysfunction forms the bulk of gestational thyroid disorders and the paucity of high-level evidence to support correction of these asymptomatic biochemical abnormalities weighs against universal screening. This review critically appraises the literature, examines the pros and cons of universal thyroid screening in pregnancy, highlighting the now strong case for implementing universal screening and explores strategies for its implementation.

Risk of Adverse Pregnancy Outcomes in Women with CKD

CKD is increasingly prevalent in pregnancy. In the Torino-Cagliari Observational Study (TOCOS), we assessed whether the risk for adverse pregnancy outcomes is associated with CKD by comparing pregnancy outcomes of 504 pregnancies in women with CKD to outcomes of 836 low-risk pregnancies in women without CKD. The presence of hypertension, proteinuria (>1 g/d), systemic disease, and CKD stage (at referral) were assessed at baseline. The following outcomes were studied: cesarean section, preterm delivery, and early preterm delivery; small for gestational age (SGA); need for neonatal intensive care unit (NICU); new onset of hypertension; new onset/doubling of proteinuria; CKD stage shift; "general" combined outcome (preterm delivery, NICU, SGA); and "severe" combined outcome (early preterm delivery, NICU, SGA). The risk for adverse outcomes increased across stages (for stage 1 versus stages 4-5: "general" combined outcome, 34.1% versus 90.0%; "severe" combined outcome, 21.4% versus 80.0%; P<0.001). In women with stage 1 CKD, preterm delivery was associated with baseline hypertension (odds ratio [OR], 3.42; 95% confidence interval [95% CI], 1.87 to 6.21), systemic disease (OR, 3.13; 95% CI, 1.51 to 6.50), and proteinuria (OR, 3.69; 95% CI, 1.63 to 8.36). However, stage 1 CKD remained associated with adverse pregnancy outcomes (general combined outcome) in women without baseline hypertension, proteinuria, or systemic disease (OR, 1.88; 95% CI, 1.27 to 2.79). The risk of intrauterine death did not differ between patients and controls. Findings from this prospective study suggest a "baseline risk" for adverse pregnancy-related outcomes linked to CKD.

Optimal management of hypothyroidism, hypothyroxinaemia and euthyroid TPO antibody positivity preconception and in pregnancy

Normal physiological changes of pregnancy warrant the need to employ gestation specific reference ranges for the interpretation of thyroid function tests. Thyroid hormones play crucial roles in foetal growth and neurodevelopment which are dependent on adequate supply of maternal thyroid hormones from early gestation onwards. The prevention of significant adverse obstetric and neurodevelopmental outcomes from hypothyroidism requires a strategy of empirical levothyroxine dose increases and predictive dose adjustments in pregnancy combined with regular thyroid function testing, starting before pregnancy and until the postpartum period. Subclinical hypothyroidism has been associated with an increased risk of pregnancy loss and neurocognitive deficits in children, especially when diagnosed before or during early pregnancy. Whilst trials of levothyroxine replacement for mild hypothyroidism in pregnancy have not indicated definite evidence of improvements in these outcomes, professional guidelines recommend treatment, especially if evidence of underlying thyroid autoimmunity is present. Studies of isolated hypothyroxinaemia in pregnancy have shown conflicting evidence with regards to adverse obstetric and neurodevelopmental outcomes and no causative relationships have been determined. Treatment of this condition in pregnancy may be considered in those with underlying thyroid autoimmunity. Whilst the evidence for a link between the presence of anti-TPO antibodies and increased risks of pregnancy loss and infertility is compelling, the results of ongoing randomized trials of levothyroxine in euthyroid women with underlying autoimmunity are currently awaited. Further studies to define the selection of women who require levothyroxine replacement and to determine the benefits of a predictive dose adjustment strategy are required.

[Thyroid dysfunction during pregnancy]

Recent clinical practice guidelines on thyroid dysfunction and pregnancy have changed health care provided to pregnant women, although their recommendations are under constant revision. Trimester- and area-specific reference ranges for serum thyroid-stimulating hormone are required for proper diagnosis of hypothyroidism and hyperthyroidism. There is no doubt on the need of therapy for overt hypothyroidism, while therapy for subclinical hypothyroidism is controversial. Further research is needed to settle adverse effects of isolated hypothyroxinemia and thyroid autoimmunity. Differentiation between hyperthyroidism due to Graves' disease and the usually self-limited gestational transient thyrotoxicosis is critical. It is also important to recognize risk factors for postpartum thyroiditis. Supplementation with iodine is recommended to maintain adequate iodine nutrition during pregnancy and avoid serious consequences in offspring. Controversy remains about universal screening for thyroid disease during pregnancy or case-finding in high-risk women. Opinions of some scientific societies and recent cost-benefit studies favour universal screening. Randomized controlled studies currently under development should reduce the uncertainties that still remain in this area.