Strengths and limitations of diagnostic tools for endometriosis and relevance in diagnostic test accuracy research

Endometriosis is a chronic systemic disease that can cause pain, infertility and reduced quality of life. Diagnosing endometriosis remains challenging, which yields diagnostic delays for patients. Research on diagnostic test accuracy in endometriosis can be difficult due to verification bias, as not all patients with endometriosis undergo definitive diagnostic testing. The purpose of this State-of-the-Art Review is to provide a comprehensive update on the strengths and limitations of the diagnostic modalities used in endometriosis and discuss the relevance of diagnostic test accuracy research pertaining to each. We performed a comprehensive literature review of the following methods: clinical assessment including history and physical examination, biomarkers, diagnostic imaging, surgical diagnosis and histopathology. Our review suggests that, although non-invasive diagnostic methods, such as clinical assessment, ultrasound and magnetic resonance imaging, do not yet qualify formally as replacement tests for surgery in diagnosing all subtypes of endometriosis, they are likely to be appropriate for advanced stages of endometriosis. We also demonstrate in our review that all methods have strengths and limitations, leading to our conclusion that there should not be a single gold-standard diagnostic method for endometriosis, but rather, multiple accepted diagnostic methods appropriate for different circumstances. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Maternal Perfluoroalkyl Substances, Thyroid Hormones, and DIO Genes: A Spanish Cross-sectional Study

Results of studies on perfluoroalkyl substances (PFASs) and thyroid hormones (THs) are heterogeneous, and the mechanisms underlying the action of PFASs to target THs have not been fully characterized. We examined the relation between first-trimester maternal PFAS and TH levels and the role played by polymorphisms in the iodothyronine deiodinase 1 (DIO1) and 2 (DIO2) genes in this association. Our sample comprised 919 pregnant Spanish women (recruitment = 2003-2008) with measurements of perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), thyroid-stimulating hormone (TSH), total triiodothyronine (TT3), and free thyroxine (FT4), and we genotyped for single-nucleotide polymorphisms in the DIO1 (rs2235544) and DIO2 (rs12885300) genes. We performed multivariate regression analyses between PFASs and THs and included the interaction term PFAS-genotypes in the models. PFHxS was associated with an increase in TSH (% change in outcome [95% CI] per 2-fold PFAS increase = 6.09 [-0.71, 13.4]), and PFOA and PFNA were associated with a decrease in TT3 (-7.17 [-13.5, -0.39] and -6.28 [-12.3, 0.12], respectively). We found stronger associations between PFOA, PFNA, and TT3 for DIO1-CC and DIO2-CT genotypes, although interaction p-values were not significant. In conclusion, this study found evidence of an inverse association between PFOA and TT3 levels. No clear effect modification by DIO enzyme genes was observed.

Ureter Visualization With Transvaginal Ultrasound: A Learning Curve Study

OBJECTIVES

To evaluate the learning curve of gynecologic surgical fellows (ie, in training) to properly identify the ureters in real time while simultaneously performing and interpreting transvaginal ultrasound (TVUS) examinations.

METHODS

We performed a prospective study, which took place at 2 centers in Sydney, Australia, from December 2017 to December 2018. Three fellows (F1-F3), of varying prestudy ultrasound (US) experience, were recruited to participate. One hundred fifty predetermined examinations were planned. A TVUS examination was performed by the study reference standard (an expert in gynecologic US). Subsequently, the fellows performed a focused component to identify bilateral ureters, having been blinded to the patient's clinical history and reference standard findings. Immediate feedback and hands-on teaching were provided after each of the fellow's evaluations were complete. To evaluate the number of scans needed to gain competency, the cumulative summation test for the learning curve was used.

RESULTS

A total of 150 examinations were performed on 145 patients. One patient had a single ureter, and 1 patient had US evidence of hydroureter. The cumulative summation test for the learning curve for bilateral ureter identification showed that F1 did not reach competency by 50 TVUS examinations, whereas F2 and F3 required 41 and 31 TVUS examinations to reach competency, respectively.

CONCLUSIONS

Contrary to other studies on the topic, this study suggests that although it is feasible for surgical fellows to learn TVUS identification of bilateral ureters, not all fellows can reach competency during a program based on a predefined number of scans. We advocate for an individualized, competency-based medical education model in learning US for identifying the ureters.

One-Size-Fits-All Approach Does Not Work for Gynecology Trainees Learning Endometriosis Ultrasound Skills

OBJECTIVES

To evaluate whether gynecologic surgical trainees (fellows) can become competent in the real-time classification of the pouch of Douglas (POD) obliteration state and direct visualization of bowel deep endometriosis (DE) during a program with a prespecified number of transvaginal ultrasound (TVUS) examinations.

METHODS

We performed a prospective study between December 2017 and December 2018. Three fellows (F1-F3) performed 50 scans each, which were all supervised by an expert sonologist, who performed the reference standard TVUS examination. The fellows performed a focused TVUS examination to assess the bowel and POD state, having been blinded to the patient's clinical history and reference standard findings. Immediate feedback and hands-on teaching were provided after each of the fellow's official classifications. To evaluate the number of scans needed to gain competency, the cumulative summation test for the learning curve was used.

RESULTS

A total of 150 examinations were performed on 145 patients. Twenty-six (17.9%) patients had a diagnosis of bowel DE, and 34 (23.4%) were classified as having a negative sliding sign by the reference standard. The overall accuracy of the presence/absence of bowel DE was 90% (range, 82%-94%). The overall accuracy of POD state classification was 93% (range, 90%-96%). The cumulative summation test for the learning curve for bowel DE showed that F1 did not reach competency by 50 scans, whereas F2 and F3 required 21 and 25 scans, respectively. For POD obliteration, F2 did not reach competency, whereas F1 and F3 required 40 and 22 scans.

CONCLUSIONS

Not all trainees can reach competency for TVUS evaluations of POD obliteration and bowel DE in a predefined number of scans.

Prevalence of negative sliding sign representing pouch of Douglas obliteration during pelvic transvaginal ultrasound for any indication

OBJECTIVES

Pouch of Douglas (POD) obliteration can be predicted with a high degree of certainty and reproducibility using the dynamic transvaginal ultrasound (TVS) sliding-sign technique. So far, studies on POD obliteration prediction have focused on tertiary-care populations with high prevalence of endometriosis; however, POD obliteration may exist in individuals with asymptomatic endometriosis or other conditions. Our primary aim was to determine the prevalence of a negative sliding sign, representing POD obliteration, in a cohort of patients undergoing TVS for any gynecological indication.

METHODS

This was a prospective observational study of consecutive women with an indication for gynecological TVS, conducted at a high-volume ultrasound practice between July and August 2018. Clinical and surgical history, indication for TVS and TVS findings were documented. The prevalence of TVS-confirmed POD obliteration, determined by interpretation of the sliding sign, was calculated for the entire cohort and for the subgroups of women with and without risk factors for endometriosis. High risk for endometriosis was defined as having (1) a TVS referral for endometriosis-like pelvic pain or endometriosis specifically and/or (2) clinical symptoms or signs suggestive of endometriosis. Low risk was defined as the absence of these characteristics.

RESULTS

During the study period, 1043 consecutive women underwent TVS. After excluding those who underwent transabdominal ultrasound, had a history of hysterectomy or with missing data, 909 women were analyzed. The prevalence of a negative sliding sign in the entire cohort was 47/909 (5.2%). A negative sliding sign was observed in 22/639 (3.4%) women with a low risk for endometriosis and 25/243 (10.3%) of those with a high risk for endometriosis (difference in proportions, 6.9% (95% CI 2.8-10.9%); P < 0.001).

CONCLUSIONS

We have demonstrated an overall prevalence of a negative sliding sign, suggesting POD obliteration, of 5.2% (or 1/20) in women seeking TVS for a gynecological indication. The prevalence of negative sliding sign in low-risk women is not negligible (3.4% or 1/29 women). These women are most likely to have asymptomatic endometriosis or another important etiology of POD obliteration. The prevalence of a negative sliding sign is approximately three-times higher in women with signs and/or symptoms of endometriosis (10.3% vs 3.4%). Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Endometriosis and the Urinary Tract: From Diagnosis to Surgical Treatment

We aim to describe the diagnosis and surgical management of urinary tract endometriosis (UTE). We detail current diagnostic tools, including advanced transvaginal ultrasound, magnetic resonance imaging, and surgical diagnostic tools such as cystourethroscopy. While discussing surgical treatment options, we emphasize the importance of an interdisciplinary team for complex cases that involve the urinary tract. While bladder deep endometriosis (DE) is more straightforward in its surgical treatment, ureteral DE requires a high level of surgical skill. Specialists should be aware of the important entity of UTE, due to the serious health implications for women. When UTE exists, it is important to work within an interdisciplinary radiological and surgical team.

SonoPODography: A new diagnostic technique for visualizing superficial endometriosis

OBJECTIVE

To perform a pilot diagnostic accuracy study of a novel transvaginal ultrasonography procedure called saline-infusion sonoPODography to predict superficial endometriosis in patients with suspected endometriosis.

STUDY DESIGN

A prospective single-center diagnostic accuracy study was performed from September 2019-November 2019. The index test sonoPODography was performed and the results were documented in a standardized fashion. SonoPODography was performed by installing saline into the pouch of Douglas (POD) via an intrauterine balloon catheter to create an acoustic window between the ultrasound probe and surrounding structures. The pelvis was then assessed for the presence or absence of superficial endometriosis using pre-defined features. Direct visualization at laparoscopy and histological assessment of excised endometriosis confirmed the outcome. The diagnostic performance of sonoPODography was evaluated.

RESULTS

42 consecutive participants underwent sonoPODography. Superficial endometriosis was identified by sonoPODography in 24/42 (57.1 %) and in 37/42 (88.1 %) participants by direct visualization at laparoscopy. The overall diagnostic performance of sonoPODography was: accuracy 69.1 %, sensitivity 64.9 %, specificity 100.0 %, positive predictive value 100.0 %, negative predictive value 27.8 %. Amongst those without deep endometriosis/endometriomas/pouch of Douglas obliteration, the diagnostic performance was: accuracy 80.0 %, sensitivity 77.7 %, specificity 100.0 %, positive predictive value 100.0 %, negative predictive value 33.3 %. The pouch of Douglas peritoneum was the most common site of superficial endometriosis.

CONCLUSIONS

SonoPODography is a novel ultrasound-based procedure that permits the direct visualization of superficial with respectable diagnostic accuracy. The findings of this pilot study are promising and justify the initiation of a larger outpatient study. SonoPODography may establish new avenues for the non-invasive diagnosis and investigation of endometriosis.

Change over time in the iodine nutritional status of pregnant women from the Pamplona healthcare region

INTRODUCTION

Adequate iodine intake is essential during pregnancy. A previous study of pregnant women from the Pamplona healthcare region showed mild iodine deficiency (mean urinary iodine level, 125 mcg/L). This study was intended to ascertain the iodine intake of pregnant women in our region and to analyze the change over time in their iodine nutritional status.

METHODS

An observational study of 400 women in their first trimester of pregnancy. An iodine intake questionnaire was administered. To assess iodine status, urinary iodine concentration (UIC) was measured in a simple urine sample, and serum thyroglobulin levels were determined. In addition, thyroid volume was measured by cervical ultrasound examination.

RESULTS

Iodized salt was used by 70.5% of all participants (55.3% since the pre-gestational period) and 98.5% of them received iodine-containing supplements (mean dose, 202.6±30.1 mcg/day). Mean urinary iodine concentration was 242 mcg/L (138.5-415.5 mcg/L) and the mean serum thyroglobulin level was 12.3 mcg/L (8.3-9 mcg/L). Iodized salt intake was associated with higher UICs and lower thyroid volume. No differences were found in any of the tested parameters regarding the intake of dairy products, fish, or eggs.

CONCLUSIONS

Iodine intake by pregnant women in Pamplona has increased due to a greater use of iodized salt and to higher doses of iodine supplements. As a result of this, an adequate iodine status has been achieved in the last decade.

A Multicenter International Temporal and External Validation Study of the Ultrasound-based Endometriosis Staging System

STUDY OBJECTIVE

The aim of this study was to validate temporally and externally the ultrasound-based endometriosis staging system (UBESS) to predict the level of complexity of laparoscopic surgery for endometriosis.

DESIGN

A multicenter, international, retrospective, diagnostic accuracy study was carried out between January 2016 and April 2018 on women with suspected pelvic endometriosis.

SETTING

Four different centers with advanced ultrasound and laparoscopic services were recruited (1 for temporal validation and 3 for external validation).

PATIENTS

Women with pelvic pain and suspected endometriosis.

INTERVENTIONS

All women underwent a systematic transvaginal ultrasound and were staged according to the UBESS system, followed by classification of laparoscopic level of complexity according to the Royal College of Obstetricians and Gynaecologists (RCOG) levels 1 to 3.

MEASUREMENTS AND MAIN RESULTS

UBESS I, II, and III were then correlated with RCOG levels 1, 2, and 3, respectively. A comparison between temporal and external sites (skipping "A") and between each site was performed in terms of the diagnostic accuracy of UBESS to predict RCOG laparoscopic skill level. A total of 317 consecutive women who underwent laparoscopy with suspected endometriosis were included. Complete transvaginal ultrasound and laparoscopic surgical outcomes were available for 293/317 (92.4%). At the temporal site, the accuracy, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio of UBESS I to predict RCOG level 1 were 80.0%,73.8%, 94.9%, 97.2%, 60.2%, 14.5%, and 0.3%, respectively; of UBESS II to predict RCOG level 2 were 81.0%, 70.6%, 82.0%, 26.7%, 96.8%, 3.9%, and 0.3%, respectively; of UBESS III to predict RCOG level 3 were 91.0%, 85.7%, 92.4%, 75.0%, 96.1%, 11.3%, and 0.2%, respectively. At the external sites, the results of UBESS I to predict RCOG level 1 were 90.3%, 92.0%, 88.4%, 90.2%, 90.5%, 7.9%, and 0.1% respectively; UBESS II to predict RCOG level 2 were 89.2%, 100.0%, 88.5%, 37.5%, 100.0%, 8.7%, and 0.0%, respectively; and UBESS III to predict RCOG level 3 were 86.0%, 67.6%, 98.2%, 96.2%, 82.1%, 37.8%, and 0.3%, respectively. When patients requiring ureterolysis (i.e., RCOG level 3) in the absence of bowel endometriosis were excluded (n = 54), the sensitivity of UBESS III to correctly classify RCOG level 3 increased from 85.7% to 96.7% at the temporal site (n = 42) and from 67.6% to 96.0% at the external sites (n = 12) (p <.005).

CONCLUSION

The results from this external validation study suggest that UBESS in its current form is not generalizable unless there is either or both bowel deep endometriosis and cul-de-sac obliteration present. The major limitation appears to be the misclassification of women who require surgical ureterolysis in the absence of bowel endometriosis.

The Use of Ultrasound in Detecting Endometriosis: Endometriotic Nodule Detected on Ultrasound but not Visualized on Laparoscopy

The gold standard for diagnosis of endometriosis remains direct visualization at laparoscopy and histological confirmation. However, ultrasound is emerging as a key modality in detecting endometriosis. This case demonstrates how ultrasound has the ability to detect lesions that may not be visible on laparoscopy. A left uterosacral ligament (LUSL) deep endometriosis (DE) nodule was detected on preoperative ultrasound. During laparoscopy, no abnormalities were visualized at that site. Given ultrasound's high specificity for DE, the LUSL was resected; histopathology confirmed DE. This case demonstrates the utility of ultrasound and its ability to detect lesions that may not be visible to a surgeon's eye at laparoscopy. Laparoscopy may fail to identify not only sites of endometriosis but also the extent of infiltration of the disease. The utility of ultrasound for pre-operative mapping can guide surgeons in targeted excision of all lesions at the time of surgery, potentially leading to lower rates of suboptimal resection and residual disease. Interestingly, this case may support the theory of müllerianosis, whereby, during fetal organogenesis, misplaced endometrial tissue develops into endometriosis, allowing it to potentially later manifest as DE.

Similarities and differences of dietary and other determinants of iodine status in pregnant women from three European birth cohorts

PURPOSE

As a component of thyroid hormones, adequate iodine intake is essential during pregnancy for fetal neurodevelopment. Across Europe, iodine deficiency is common in pregnancy, but data are lacking on the predictors of iodine status at this life stage. We, therefore, aimed to explore determinants of iodine status during pregnancy in three European populations of differing iodine status.

METHODS

Data were from 6566 pregnant women from three prospective population-based birth cohorts from the United Kingdom (ALSPAC, n = 2852), Spain (INMA, n = 1460), and The Netherlands (Generation R, n = 2254). Urinary iodine-to-creatinine ratio (UI/Creat, µg/g) was measured in spot-urine samples in pregnancy (≤ 18-weeks gestation). Maternal dietary intake, categorised by food groups (g/day), was estimated from food-frequency questionnaires (FFQs). Multivariable regression models used dietary variables (energy-adjusted) and maternal characteristics as predictors of iodine status.

RESULTS

Median UI/Creat in pregnant women of ALSPAC, INMA, and Generation R was 121, 151, and 210 µg/g, respectively. Maternal age was positively associated with UI/Creat in all cohorts (P < 0.001), while UI/Creat varied by ethnicity only in Generation R (P < 0.05). Of the dietary predictors, intake of milk and dairy products (per 100 g/day) was positively associated with UI/Creat in all cohorts [ALSPAC (B = 3.73, P < 0.0001); INMA (B = 6.92, P = 0.002); Generation R (B = 2.34, P = 0.001)]. Cohort-specific dietary determinants positively associated with UI/Creat included fish and shellfish in ALSPAC and INMA, and eggs and cereal/cereal products in Generation R.

CONCLUSIONS

The cohort-specific dietary determinants probably reflect not only dietary habits but iodine-fortification policies; hence, public-health interventions to improve iodine intake in pregnancy need to be country-specific.

Association of Maternal Iodine Status With Child IQ: A Meta-Analysis of Individual Participant Data

CONTEXT

Although the consequences of severe iodine deficiency are beyond doubt, the effects of mild to moderate iodine deficiency in pregnancy on child neurodevelopment are less well established.

OBJECTIVE

To study the association between maternal iodine status during pregnancy and child IQ and identify vulnerable time windows of exposure to suboptimal iodine availability.

DESIGN

Meta-analysis of individual participant data from three prospective population-based birth cohorts: Generation R (Netherlands), INMA (Spain), and ALSPAC (United Kingdom); pregnant women were enrolled between 2002 and 2006, 2003 and 2008, and 1990 and 1992, respectively.

SETTING

General community.

PARTICIPANTS

6180 mother-child pairs with measures of urinary iodine and creatinine concentrations in pregnancy and child IQ. Exclusion criteria were multiple pregnancies, fertility treatment, medication affecting the thyroid, and preexisting thyroid disease.

MAIN OUTCOME MEASURE

Child nonverbal and verbal IQ assessed at 1.5 to 8 years of age.

RESULTS

There was a positive curvilinear association of urinary iodine/creatinine ratio (UI/Creat) with mean verbal IQ only. UI/Creat <150 µg/g was not associated with lower nonverbal IQ (-0.6 point; 95% CI: -1.7 to 0.4 points; P = 0.246) or lower verbal IQ (-0.6 point; 95% CI: -1.3 to 0.1 points; P = 0.082). Stratified analyses showed that the association of UI/Creat with verbal IQ was only present up to 14 weeks of gestation.

CONCLUSIONS

Fetal brain development is vulnerable to mild to moderate iodine deficiency, particularly in the first trimester. Our results show that potential randomized controlled trials investigating the effect of iodine supplementation in women with mild to moderate iodine deficiency on child neurodevelopment should begin supplementation not later than the first trimester.

A Novel Ultrasound Technique Called Saline Infusion SonoPODography to Visualize and Understand the Pouch of Douglas and Posterior Compartment Contents: A Feasibility Study

Women with infertility are often investigated with saline-infusion sonohysterography and hysterosalpingo-contrast-sonography. The high prevalence of endometriosis in this population also warrants an evaluation with transvaginal ultrasound for deep endometriosis. To minimize investigations, we prospectively evaluated the feasibility of a novel combined ultrasound technique called saline-infusion sonoPODography. In most patients, the fluid infused to assess the cavity and tubal patency spilled through patent tubes and filled the pouch of Douglas, yielding a "standoff" view of posterior compartment structures, including uterosacral ligaments, rectovaginal septum, and the pouch of Douglas. We believe this improved our ability to evaluate this space.

Iodine contents in conventional ultra-high temperature (UHT) processed cow milk: Changes over the year and regional differences. Implications for epidemiological studies on iodine nutritional status

BACKGROUND AND OBJECTIVES

Ultra-high temperature (UHT) processed cow milk is the milk most commonly consumed in Southwest Europe. The study objectives were: 1) to describe the pattern followed by iodine concentration (IC) in conventional UHT milk over the year, and 2) to find out any differences in IC in this type of milk depending on its geographical origin.

MATERIAL AND METHODS

Bricks of conventional UHT cow milk of commercial brands available in food stores in Vitoria-Gasteiz (Araba/Álava), Basque Country (Spain) were bought for 12 consecutive months, and their ICs were measured using high performance liquid chromatography.

RESULTS

Median (P₂₅-P₇₅) IC in UHT milk (n=489) was 190 (159-235)μg/L. IC in milk showed great changes over the year, reaching peak values between January and May (241 [201-272]μg/L), and minimal levels between July and November (162 [134-185]μg/L) (P<.0001). The IC of milk packed in Germany was significantly lower than that of milks packed in Spain and France, 119 (106-156)μg/L versus 189 (159-229)μg/L and 205 (176-243)μg/L respectively (P<.0001).

CONCLUSIONS

Conventional UHT cow milk is a very important nutritional source of iodine, but its IC is highly variable. Knowledge of the pattern followed by IC in milk over the year is of great interest for planning epidemiological studies on iodine nutritional status in schoolchildren and for interpretation of their results.

Doppler Color Scoring System in Women With an Incomplete Miscarriage: Interobserver and Intraobserver Reproducibility Study

OBJECTIVES

Doppler Color Scoring (DCS) has been used to predict successful expectant management of incomplete miscarriage. The aim of this study was to assess inter- and intraobserver reproducibility of the DCS system in women with incomplete miscarriage noted on transvaginal sonography.

METHODS

This was a prospective reproducibility study involving offline analysis of 32 prerecorded video sets on transvaginal sonography in real time of women with incomplete miscarriage. Vascularization of retained products of conception was recorded using the DCS system adopted from the International Ovarian Tumor Analysis group. Five gynecologic sonologists of varying experience assigned a DCS classification to each video in the analysis. The same videos were reanalyzed, in a different order, at least 7 days later, to assess intraobserver agreement. Inter- and intraobserver correlations were performed to determine agreement. Interobserver agreement was also measured between each observer and the reference standard (G.C.). A Cohen's κ coefficient value less than 0 suggests poor agreement, 0.01 to 0.20 slight, 0.21 to 0.40 fair, 0.41 to 0.60 moderate, 0.61 to 0.80 substantial, and 0.81 and 0.99 almost perfect.

RESULTS

Interobserver agreement for all observers for DCS allocation ranged from 0.480 to 0.751. Overall interobserver agreement for 5 observers was substantial (κ, 0.626). Overall interobserver agreements for the 2 inexperienced and 3 experienced observers compared to G.C. were 0.521 and 0.618, respectively. Experienced observers achieved overall almost perfect intraobserver agreement, compared to substantial agreement for inexperienced sonologists.

CONCLUSIONS

DCS interobserver reproducibility between all observers and GC ranged from moderate to substantial. DCS intraobserver reproducibility was substantial to almost perfect. The DCS system appears to be a reproducible tool in evaluating women with incomplete miscarriage.

Iodine nutrition status in Spain Needs for the future

Although iodine nutrition in Spain has improved in recent years, the problem is not completely resolved. It is necessary that health institutions establish measures to ensure an adequate iodine nutrition of the population, especially among the highest risk groups (children and adolescents, women of childbearing age, pregnant women and nursing mothers). A low salt intake should be advised, but it should be iodized. It is also imperative that food control agencies establish effective control over adequate iodization of salt. Indicators on iodine nutrition should be included in future health surveys. The EUthyroid study and the Krakow Declaration on iodine nutrition provide an opportunity to set up a pan-European plan for the prevention of iodine deficiency that should be considered and used by health authorities.

Thyroid Function Reference Values in Healthy Iodine-Sufficient Pregnant Women and Influence of Thyroid Nodules on Thyrotropin and Free Thyroxine Values

BACKGROUND

Thyroid function assessment in pregnancy requires specific reference intervals stratified by gestational age and according to each laboratory method. Thyroid nodules may influence thyroid function in pregnant women. The aims of this study were to define the reference values of thyrotropin (TSH) and free thyroxine (fT4) in the three pregnancy trimesters in iodine-sufficient pregnant women, and to analyze the influence of thyroid nodules on thyroid function during pregnancy.

METHODS

This was a prospective, longitudinal study comprising 400 pregnant women with no history of thyroid disease and no medication influencing thyroid function. TSH, fT4, antithyroglobulin, and antithyroid peroxidase antibodies were measured each trimester by chemiluminescent immunoassays. Urinary iodine concentration was measured in the first trimester when a thyroid echography was also performed. Women with multiple gestation pregnancies, positive thyroid autoimmunity, TSH values >5 or <0.1 mIU/L with a simultaneous fT4 level above the general population reference value in the first trimester, or clinically significant thyroid nodules (nodules ≥1 cm and/or multiple nodules) were excluded to establish TSH and fT4 reference values.

RESULTS

Reference intervals in the first, second, and third trimesters were 0.13-4.16, 0.31-3.73, and 0.58-4.36 mIU/L, respectively, for TSH, and 0.85-1.24, 0.82-1.20, and 0.67-1.06 ng/dL, respectively, for fT4. The total prevalence of thyroid nodules was 28.8% [95% confidence interval (CI) 24.4-33.5%], and 6.0% of the participants showed clinically significant nodules. Pregnant women with thyroid nodules (n = 115) showed consistently lower TSH values during all pregnancy stages (first trimester: median 1.14 mIU/L [interquartile range (IQR) 0.53-1.75 mIU/L] vs. 1.48 mIU/L [IQR 0.94-2.19 mIU/L], p < 0.001; second trimester: 1.22 mIU/L [IQR 0.66-1.77 mIU/L] vs. 1.45 mIU/L [1.04-2.05 mIU/L], p = 0.001; third trimester: 1.74 mIU/L [IQR 1.08-2.36 mIU/L] vs. 1.93 mIU/L [IQR 1.37-2.58 mIU/L], p = 0.041) and higher fT4 values in the first trimester (M ± SD = 1.08 ± 0.14 ng/dL vs. 1.03 ± 0.12, p < 0.001) compared to those without nodules (n = 285). Both pregnant women with clinically significant thyroid nodules and those with nonsignificant ones had lower TSH values than women without nodules.

CONCLUSIONS

TSH/fT4 reference intervals in pregnant women from the authors' geographical area will thyroid dysfunction in pregnancy to be appropriately diagnosed. The prevalence of thyroid nodules is high in iodine-sufficient pregnant women, and is associated with low TSH values across pregnancy.

Newborn screening for homocystinurias: Recent recommendations versus current practice

PURPOSE

To assess how the current practice of newborn screening (NBS) for homocystinurias compares with published recommendations.

METHODS

Twenty-two of 32 NBS programmes from 18 countries screened for at least one form of homocystinuria. Centres provided pseudonymised NBS data from patients with cystathionine beta-synthase deficiency (CBSD, n = 19), methionine adenosyltransferase I/III deficiency (MATI/IIID, n = 28), combined remethylation disorder (cRMD, n = 56) and isolated remethylation disorder (iRMD), including methylenetetrahydrofolate reductase deficiency (MTHFRD) (n = 8). Markers and decision limits were converted to multiples of the median (MoM) to allow comparison between centres.

RESULTS

NBS programmes, algorithms and decision limits varied considerably. Only nine centres used the recommended second-tier marker total homocysteine (tHcy). The median decision limits of all centres were ≥ 2.35 for high and ≤ 0.44 MoM for low methionine, ≥ 1.95 for high and ≤ 0.47 MoM for low methionine/phenylalanine, ≥ 2.54 for high propionylcarnitine and ≥ 2.78 MoM for propionylcarnitine/acetylcarnitine. These decision limits alone had a 100%, 100%, 86% and 84% sensitivity for the detection of CBSD, MATI/IIID, iRMD and cRMD, respectively, but failed to detect six individuals with cRMD. To enhance sensitivity and decrease second-tier testing costs, we further adapted these decision limits using the data of 15 000 healthy newborns.

CONCLUSIONS

Due to the favorable outcome of early treated patients, NBS for homocystinurias is recommended. To improve NBS, decision limits should be revised considering the population median. Relevant markers should be combined; use of the postanalytical tools offered by the CLIR project (Collaborative Laboratory Integrated Reports, which considers, for example, birth weight and gestational age) is recommended. tHcy and methylmalonic acid should be implemented as second-tier markers.

Imaging techniques in endometriosis

Endometriosis is a common gynecological condition affecting up to 15% of the general female population. Here, we present a systematic review of imaging techniques of endometriosis. The aim of this review is to determine the most accurate site-specific preoperative diagnostic tools in order to map, locate, evaluate the extension, and stage the disease. There are important reasons to stage endometriosis: to create a common language, to enable specificity of diagnosis, standardize comparisons, and to facilitate research applications. The requirements of an ideal endometriosis classification system are that it be empirically and scientifically based, be of general consensus, have unambiguous definition of terms, be comprehensive in all cases, have a simple translation from anatomic features to verbal description, reflect disease, predict fertility, predict pain relief, be useful to guide treatment, indicate risk of recurrence, identify clinical situations in which it does not apply, be simple to calculate, and be easy to communicate to women. An extensive search of papers regarding imaging techniques in endometriosis was performed in Pubmed from January 1992 to February 2018, including original peer-reviewed papers, reviews, and international guidelines.

Thyroid Function in Early Pregnancy, Child IQ, and Autistic Traits: A Meta-Analysis of Individual Participant Data

CONTEXT

Low maternal free T4 (FT4) has been associated with poor child neurodevelopment in some single-center studies. Evidence remains scarce for the potential adverse effects of high FT4 and whether associations differ in countries with different iodine status.

OBJECTIVE

To assess the association of maternal thyroid function in early pregnancy with child neurodevelopment in countries with a different iodine status.

DESIGN, SETTING, AND PARTICIPANTS

Meta-analysis of individual participant data from 9036 mother-child pairs from three prospective population-based birth cohorts: INMA [Infancia y Medio Ambiente (Environment and Childhood project) (Spain)], Generation R (Netherlands), and ALSPAC (Avon Longitudinal Study of Parents and Children, United Kingdom). The exclusion criteria were multiple pregnancies, fertility treatments, thyroid-interfering medication usage, and known thyroid disease.

MAIN OUTCOMES

Child nonverbal IQ at 5 to 8 years of age, verbal IQ at 1.5 to 8 years of age, and autistic traits within the clinical range at 5 to 8 years of age.

RESULTS

FT4 <2.5th percentile was associated with a 3.9-point (95% CI, -5.7 to -2.2) lower nonverbal IQ and a 2.1-point (95% CI, -4.0 to -0.1) lower verbal IQ. A suggestive association of hypothyroxinemia with a greater risk of autistic traits was observed. FT4 >97.5th percentile was associated with a 1.9-fold (95% CI, 1.0 to 3.4) greater risk of autistic traits. No independent associations were found with TSH.

CONCLUSIONS

Low maternal FT4 was consistently associated with a lower IQ across the cohorts. Further studies are needed to replicate the findings of autistic traits and investigate the potential modifying role of maternal iodine status. FT4 seems a reliable marker of fetal thyroid state in early pregnancy, regardless of the type of immunoassay.

Iodine intake from supplements and diet during pregnancy and child cognitive and motor development: the INMA Mother and Child Cohort Study

Background

The effect of mild-to-moderate maternal iodine deficiency on the neuropsychological development of their offspring is uncertain. We aimed to assess the association between iodine status during pregnancy and the cognitive and motor development of children at 4–5 years.

Methods

We conducted a prospective cohort study in four Spanish regions with recruitment of pregnant women between 2003 and 2008 and follow-up of their children up to 4–5 years (mean (SD)=4.8 (0.6)). Cognitive and motor function was assessed in 1803 children using the McCarthy Scales of Children’s Abilities. Dietary iodine and supplementation were measured through questionnaires twice during pregnancy. Urinary iodine concentration (UIC) was measured in spot samples. The residuals of a regression of UIC against creatinine were used to define a variable corrected for creatinine (UIC~Cr).

Results

Neither iodine supplements nor iodised salt consumption or maternal UIC were associated with cognitive or motor function. After adjusting for creatinine, children of women with UIC~Cr <100 µg/L had 3.93 (95% CI −6.18 to –1.69) general cognitive scores lower than the reference (150–249 µg/L). Dietary iodine was inversely associated with motor scores and milk but not other dairy products or seafood consumption accounted for this association (beta: −1.36; 95% CI −2.12 to –0.61; per one daily milk serving).

Conclusions

We found an association between low maternal urinary iodine and lower cognitive scores in childhood, although only when corrected for creatinine, adding to the evidence that iodine deficiency may have potential harmful effects on neurodevelopment. Iodine supplementation does not appear to improve child’s neurodevelopment at 4–5 years.

Association between exposure to organochlorine compounds and maternal thyroid status: Role of the iodothyronine deiodinase 1 gene

INTRODUCTION

Exposure to organochlorine compounds (OCs) may interfere with thyroid hormone (TH) homeostasis. The disruption of the deiodinase (DIO) enzymes has been proposed as a mechanism of action.

AIM

To evaluate the association between exposure to OCs and TH status in pregnant women, as well as to explore the role of genetic variations in the DIO1 and DIO2 genes.

METHODS

The study population (n=1128) was composed of pregnant women who participated in the INMA Project (Spain, 2003-2006). Hexachlorobenzene (HCB), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (4,4´-DDE), b-hexachlorocyclohexane (b-HCH), polychlorobiphenyl (PCB) congeners 138, 153 and 180, thyroid stimulating hormone (TSH), total triiodothyronine (TT3) and free thyroxine (FT4) were measured in serum samples taken during the first trimester of pregnancy (mean [standard deviation (SD)]: 13.5 [2] weeks of gestation). Polymorphisms in DIO1 (rs2235544) and DIO2 (rs12885300) were genotyped in maternal DNA. Sociodemographic and dietary characteristics were obtained by questionnaire.

RESULTS

A 2-fold increase in HCB was associated with lower TT3 (% change=-1.48; 95%CI: -2.36, -0.60). Women in the third tertile for b-HCH had lower TT3 (% change=-3.19; 95%CI: -5.64, -0.67). The interactions between DIO1 rs2235544 and PCB153 and b-HCH were statistically significant. The inverse association between PCB153 and TT3 was the strongest among women with AA genotype. Women with CC genotype presented the strongest inverse association between b-HCH and FT4.

CONCLUSION

Exposure to HCB and b-HCH was associated to a disruption in maternal TT3. The DIO1 rs2235544 SNP modified the association between exposure to some of the OCs (specifically b-HCH and PCB153) and maternal thyroid hormone levels. These results strengthen the hypothesis that DIO enzymes play a role in explaining the disruption of thyroid hormones in relation to exposure to OCs.

Sonographic Evaluation of Fetal Adrenal Gland in Gestational Diabetes: Relation to Fetal Growth and Maternal Biochemical Markers

OBJECTIVES

To relate measurements and volume of the fetal adrenal gland in third trimester ultrasound in diabetic pregnancies (1) to birth weight; (2) to other sonographic markers of diabetic fetopathy (expected fetal weight, sectional area, and fractional volume in fetal limbs); and (3) to maternal biochemical markers of diabetes (HbA1c, leptin).

METHODS

Fetal adrenal gland measurements were obtained between 32 and 34 weeks. The gland length, width, depth, and volume (by Virtual Organ Computer-Aided Analysis [VOCAL]) were measured for total gland and fetal zone. Fetal total and fat sectional area and fractional volume were obtained in arm and thigh. A maternal blood sample was obtained. Univariate and multivariate models were used to assess the associations.

RESULTS

Thirty-nine diabetic pregnancies were included. Birth weight related significantly to total and fetal zone adrenal depth, and total adrenal volume in third trimester. Total adrenal length and corrected adrenal gland volume also showed a significant correlation to birth weight percentile in univariate and multivariate models. Total adrenal volume associated significantly to total and fat areas and volumes in fetal limbs. Both maternal leptin and HbA1c levels found a significant positive relation to fetal total adrenal volume and corrected adrenal gland volume. Total adrenal gland volume showed a significant association to maternal HbA1c level in multivariate model.

CONCLUSIONS

An enlargement of the fetal adrenal gland may be observed in gestational diabetes, not only related to birth weight, but also to distinctive features of diabetic pregnancies, such as fat tissue fetal deposits or maternal biochemical markers.

Comparison of urinary iodine levels in women of childbearing age during and after pregnancy

PURPOSE

Median urinary iodine concentration (UIC) is used to describe the iodine status of a population. However, the link between UIC and iodine intake may vary during pregnancy. The aim of this study was to compare UIC during and after pregnancy, adjusting for factors that affect iodine intake.

METHODS

Two repeated measures of UIC and data on maternal iodine intake estimated through questionnaires were collected during pregnancy and 1-4 years after pregnancy in a subsample of women (n = 598) from a mother and child cohort study in Spain. Random-effects interval regression was used to assess the changes in UIC according to pregnancy status.

RESULTS

Median UIC was similar during (133 μg/L) and after pregnancy (139 μg/L). After adjusting for iodised salt, iodine supplement consumption, and socio-demographic related variables, UIC was 24.0% (95% CI 11.3, 38.2) higher after than during pregnancy. This difference was maintained in a subsample of women with exhaustive information on diet (n = 291): 26.2%, 95% CI 10.3, 44.4.

CONCLUSIONS

In an iodine sufficient area for the general population, iodine excretion was lower during than after pregnancy when factors affecting iodine intake were controlled for. Current recommendations of median UIC during pregnancy are based on the equivalence between iodine intake and UIC estimated from studies in non-pregnant populations, which might lead to overestimation of iodine deficiency during gestation. Further studies should evaluate the equivalence between iodine intake and its urinary excretion during pregnancy.

Weight-related and analytical maternal factors in gestational diabetes to predict birth weight and cord markers of diabetic fetopathy

OBJECTIVE

The objective was to determine the value of clinical and analytical maternal factors to predict birth weight and umbilical cord biochemical markers of diabetic fetopathy.

METHODS

Prospective evaluation of gestational diabetes pregnancies (n = 50). Maternal weight-related clinical and analytical factors were collected during pregnancy. After birth, an umbilical cord sample was taken.

RESULTS

Univariate linear regression analysis showed relationship between maternal weight, glycated hemoglobin (HbA1c) and insulin-like growth factor 1 (IGF1) with birth weight percentile. A significant association was found between maternal weight and cord insulin and C-peptide. Maternal HbA1c, leptin and insulin during pregnancy showed a positive linear association to cord leptin, insulin and C-peptide. In multivariate analysis models, final maternal BMI showed an independent positive association with cord C-peptide.

CONCLUSIONS

Maternal weight-related and analytical parameters show diagnostic value to birth weight and cord markers.

Vitamin D Status in Pregnancy and Determinants in a Southern European Cohort Study

BACKGROUND

Population-based data on vitamin D status in pregnancy in southern European countries are scarce. We assessed the prevalence and determinants of vitamin D insufficiency and deficiency in pregnancy in Spain.

METHODS

Plasma 25-hydroxyvitamin D3 (25(OH)D3) concentration was measured at the first trimester of gestation in 2,036 pregnant women from several geographical areas of Spain (latitude 39-42°N). Uni- and multivariable regression models were conducted to identify predictors of circulating 25(OH)D3 concentration and vitamin D insufficiency (20-30 ng/mL) and deficiency (<20 ng/mL).

RESULTS

Thirty-one per cent and 18% of women were vitamin D insufficient and deficient, respectively. Season at blood collection, latitude, age, social class, tobacco smoking, physical activity and use of vitamin D supplements were identified as independent determinants of 25(OH)D3 concentration. Lower risk of vitamin D insufficiency and deficiency was associated with summer season at blood collection (RR for insufficiency = 0.34, confidence intervals (CI) 0.25, 0.48; and RR for deficiency = 0.07, 95% CI 0.04, 0.12), southern latitude (RR for insufficiency = 0.71, 95% CI 0.50, 1.02; RR for deficiency = 0.60, 95% CI 0.38, 0.94); use of vitamin D supplements (RR for insufficiency = 0.50, 95% CI 0.35, 0.71; RR for deficiency = 0.24, 95% CI 0.14, 0.41); and strong physical activity (RR for insufficiency = 0.80, 95% CI 0.58, 1.09; and RR for deficiency = 0.67, 95% CI 0.46, 1.03). Higher risk of vitamin D deficiency was related to lower social class (RR = 1.94, 95% CI 1.19, 3.16) and smoking (RR = 1.76, 95% CI 1.23, 2.54).

CONCLUSIONS

Vitamin D insufficiency and deficiency are highly prevalent in pregnancy. Recommendations and policies to detect and prevent hypovitaminosis D during pregnancy should be developed taking into account the associated factors.

Second-hand smoke exposure in 4-year-old children in Spain: Sources, associated factors and urinary cotinine

INTRODUCTION

Second-hand smoke exposure (SHS) in children remains as a major pollution problem, with important consequences for children's health. This study aimed to identify the sources of exposure to SHS among 4-year-old children, comparing self-reports to a urinary biomarker of exposure, and characterize the most important variables related to SHS exposure in this population.

METHODS

4-year-old children's exposure to SHS was assessed by a parental-reported questionnaire and by urinary cotinine (UC) measurements in 1757 participants from 4 different areas of the Spanish INMA (INfancia y Medio Ambiente - Environment and Childhood) Project. The questionnaire about SHS included information about smoking habits at home by household members, and about exposure to SHS in other places including other homes, bars, restaurants or transportation. The association between quantified UC levels (>4ng/ml) and sociodemographic variables and the different sources of SHS exposure was examined using logistic regression.

RESULTS

Based on parental reports, 21.6% of the children were exposed to SHS at home and 47.1% elsewhere; making a total 55.9% of the children exposed to SHS. In addition, 28.2% of the children whose parents reported being not regularly exposed to SHS had quantified UC values. Children from younger mothers (<34 vs. ≥39.4 y) had a higher odds of exposure to SHS [OR (95% CI): 2.28 (1.70-3.05) per year], as well as from families with a lower educational level [OR secondary: 2.12 (1.69-2.65); primary or less: 2.91 (2.19-3.88)]. The odds of quantifiable UC in children dropped after the smoking ban in public places [OR=0.59 (0.42-0.83)]. Regarding the sources of SHS exposure we observed that quantifiable UC odds was increased in children whose parents smoked at home in their presence [OR mother occasionally: 13.39 (7.03-25.50); mother often: 18.48 (8.40-40.66); father occasionally: 10.98 (6.52-18.49); father often: 11.50 (5.96-22.20)] or in children attending other confined places, mainly other houses where people smoked [OR: 2.23 (1.78-2.80)].

CONCLUSIONS

Children's SHS exposure is nowadays an unresolved major public health problem in Spain. After the ban of smoking in public places health care professionals should put more emphasis to the parents on the importance of controlling the exposure of their children in private spaces.

Synergism between exposure to mercury and use of iodine supplements on thyroid hormones in pregnant women

OBJECTIVE

To evaluate the association between mercury exposure and thyroid-stimulating hormone (TSH), total triiodothyronine (TT3) and free thyroxine (FT4) levels during pregnancy as well as to explore if there is any synergic action between mercury and intake of iodine from different sources.

METHODS

The study population was 1407 pregnant women participating in the Spanish INMA birth cohort study. Total mercury concentrations were analyzed in cord blood. Thyroid hormones (THs) were measured in serum samples collected at 13.2±1.5 weeks of gestation. The association between mercury and TH levels was evaluated with multivariate linear regression models. Effect modification caused by iodine intake from supplements and diet was also evaluated.

RESULTS

The geometric means of TSH, TT3, FT4 and mercury were 1.1μU/L, 2.4nmol/L, 10.5pmol/L and 7.7μg/L, respectively. Mercury levels were marginally significantly associated with TT3 (β: -0.05; 95%CI: -0.10, 0.01), but were neither associated with TSH nor FT4. The inverse association between mercury and TT3 levels was stronger among the iodine supplement consumers (-0.08; 95%CI: -0.15, -0.02, interaction p-value=0.07). The association with FT4 followed the same pattern, albeit not significant.

CONCLUSION

Prenatal mercury exposure was inversely associated with TT3 levels among women who took iodine supplements during pregnancy. These results could be of public health concern, although further research is needed.

[Prevalence of vitamin d deficiency and insuffiency and associated factors in pregnant women of northern Spain]

BACKGROUND AND OBJECTIVES

The vitamin D deficiency during pregnancy has been associated with adverse events during pregnancy and the postnatal child development. In this study we examined plasma levels of vitamin D [25(OH)D3] and factors associated with plasma deficiency and insufficiency in pregnant women in northern Spain.

METHODS

We analyzed data from 453 pregnant women participating in the INMA-Asturias cohort in which was determined 25(OH)D3 by high resolution liquid chromatography.Dietary intake of vitamin D was estimated through a food frequency validated questionnaire. We estimated the prevalence of deficiency [25(OH)D3 <20 ng/ml] and insufficiency [20 to 29.9 ng / ml] of vitamin D and analyzed the distribution of 25(OH)D3 per month extraction and other factors.

RESULTS

The mean concentration of 25(OH)D3 was 27.7 ng/ml (range 6.4 to 69.5). 27.4% of pregnant women had deficient levels and 35.3% inssuficient. Levels of 25(OH)D3 were higher in the summer months (median 34.1 ng/ml). There was a higher percentage of deficiency in pregnant women with overweight/obesity (34.5%) and under 25 years (47.8%). The average daily intake of vitamin D was 5.48 mg / day (SD 2.82 range 1.09 to 32.52).Intake during the months of October to May was associated with levels of 25(OH)D3. 8.6% reported taking supplements of vitamin D.

CONCLUSIONS

We detected a high proportion of pregnant women with deficient or insufficient vitamin D levels, especially in the months of October to May, in pregnant women with overweight and obesity, and the youngest.

Clinical value of maternal bile Acid quantification in intrahepatic cholestasis of pregnancy as an adverse perinatal outcome predictor

AIMS

To evaluate the correlation between perinatal outcome and bile acid levels in intrahepatic cholestasis of pregnancy (ICP), and to evaluate variations in the mean bile acid level when stratifying by maternal and perinatal factors. A comparison between mild and severe ICP was made.

METHODS

A prospective observational study was performed in pregnant patients who underwent blood tests for bile acids due to persistent pruritus. Based on bile acid levels, maternal and neonatal data were obtained and were compared between patients presenting with ICP and gestational pruritus (normal bile acid level).

RESULTS

A total of 145 patients were included, 47 of whom were diagnosed as ICP (52 newborns) and 98 as gestational pruritus (102 newborns). The ICP group had a higher rate of NICU admission (14/42 vs. 6/98, p < 0.001) and global neonatal morbidity (13/42 vs. 9/98, p = 0.002), but these differences were no longer seen after adjusting for gestational age, singleton pregnancies and induction of labour. Patients presenting with severe ICP (maximum bile acids levels above 40 µmol/l) showed a higher rate of meconium-stained amniotic fluid (0/28 vs. 4/14, p = 0.009), NICU admission (9/34 vs. 11/17, p = 0.01) and neonatal global morbidity (5/32 vs. 8/17, p = 0.02).

CONCLUSIONS

ICP patients have higher rates of adverse neonatal outcomes when compared to those with gestational pruritus. Some of this neonatal morbidity may be secondary to late spontaneous preterm deliveries, multiple gestation and a policy of elective induction of labour after 37 weeks of gestation. A comparison of outcomes among patients with mild and severe ICP shows that the severely affected group has higher rates of meconium-stained amniotic fluid and neonatal morbidity.

Normal intellectual development in children born from women with hypothyroxinemia during their pregnancy

Proper maternal thyroid function is known to be essential for neural differentiation and migration in the fetus during the first half of pregnancy. The objectives of this study were to assess the relationship between thyroxin levels, in pregnant women with no thyroid disease and the intellectual development of their offspring in a non-iodine-deficient area, and to know specifically whether or not isolated hypothyroxinemia during pregnancy was associated with a lower intelligence in the offspring. Previously we had publicated values TSH, FT4, free T3 (FT3), anti-thyroid peroxidase antibodies (TPO Abs) and urinary iodine concentration (UIC) in 1322 pregnant women in our hospital area. Now we presented results of intelligence quotient in children born from these pregnancies. We assessed 455 children at one year of age using Brunet-Lezine scale. Of these, 289 children were evaluated again at 6-8 years of age using the WISC-IV. From the total group of children recruited, we established as control subgroup, children born of rigorously normal pregnancies (women with UIC > 150 μg/L, FT4>10th percentile and TPO-Ab negative in both trimesters). The remaining children were divided into two subgroups: those born to mothers with FT4 below the 10th percentile and the rest. No correlation was found between FT4 maternal levels, in either of trimesters studied, and the intellectual scores of offspring. No differences were found in intellectual scores comparing children born to mothers with hypothyroxinemia and those whose mothers were euthyroxinemic in both trimesters, or with the control subgroup. As conclusions we did not find any association between the levels of maternal FT4 during pregnancy and the subsequent intellectual development the offspring from these pregnancies. We attribute this result to the fact that all the pregnant women included had normal thyroid function.