Asistencia del recién nacido con hernia diafragmática congénita / Care of newborns with congenital diaphragmatic hernia / Cuidados ao recém-nascido com hérnia diafragmática congênita

La hernia diafragmática congénita es un defecto en el diafragma que lleva a la herniación del contenido abdominal a la cavidad torácica durante el período intrauterino. La morbimortalidad está determinada por la asociación con otras malformaciones, el grado de hipoplasia pulmonar y la presencia de hipertensión pulmonar secundaria. Presenta una incidencia estimada de 1 cada 2.500-3.000 recién nacidos vivos, constituyendo en un 60% una malformación aislada. Es una patología evolutiva que puede ser diagnosticada a partir de la semana 20-24, la ubicación más habitual es la posterolateral izquierda. Se trata de una patología que requiere ingreso a cuidados intensivos al nacimiento y luego de lograda la estabilización del paciente es de sanción quirúrgica. Los objetivos de este trabajo son conocer las características generales de la patología para sistematizar el manejo logrando así un óptimo asesoramiento de los padres a nivel prenatal y seguimiento postnatal del recién nacido.

Congenital diaphragmatic hernia is a defect in the diaphragm that leads to herniation of theabdominal contents of the thoracic cavity during the intrauterine period. Morbidity and mortality are determined by the association with other malformations, the degree ofpulmonary hypoplasia and the presence of secondary pulmonary hypertension.It has an estimated incidence of 1 every 2,500-3,000 live newborns, and in 60% of the cases it is an isolated malformation. It is an evolutionary pathology that can be diagnosed from week 20-24; it is most commonly located in the left posterolateral. It is a pathology that requires intensive care at birth and after delivery and once the patient has been stabilized, surgical action is required. The objectives of this work are to understand the general characteristics of the pathology in order to refine its manipulation and achieve optimal counseling for parents at the newborn's prenatal and postnatal stages.

A hérnia diafragmática congênita é um defeito no diafragma que leva à herniação doconteúdo abdominal para a cavidade torácica durante o período intrauterino. A morbimortalidade é determinada pela associação com outras malformações, pelo grau de hipoplasia pulmonar e pela presença de hipertensão pulmonar secundária. Apresenta uma incidência estimada de 1 a cada 2.500-3.000 nascidos vivos, constituindo-se em 60% uma malformação isolada. É uma patologia evolutiva que pode ser diagnosticada a partir da semana 20-24 e a localização mais comum é o póstero-lateral esquerdo. É uma patologia que requer internação em terapia intensiva ao nascimento e após o parto. Uma vez que o paciente for estabilizado, é necessária ação cirúrgica. Os objetivos deste paper são conhecer as características gerais da patologia para melhorar o seu manejo, obtendo assim um aconselhamento ideal para os pais no nível pré-natal e no acompanhamento do crescimento pós-natal do recém-nascido.

Diagnostic testing after positive results on cell free DNA screening: CVS or Amnio?

OBJECTIVE: The positive predictive values of cell free DNA (cfDNA) and rates of confined placental mosaicism (CPM), imprinting and other factors vary by chromosome. METHODS: We sought to review the literature for each of these features for each chromosome and provide recommendations on chorionic villus sampling (CVS) versus amniocentesis after an abnormal cfDNA result. RESULTS: For chromosomes with high rates of CPM (trisomy 13, monosomy X and rare autosomal trisomies [RATs]), an amniocentesis should be considered if the first trimester ultrasound is normal. For monosomy X on cfDNA with an unaffected fetus, maternal karyotyping should be considered after normal fetal diagnostic testing. In cfDNA cases with a trisomy involving a chromosome with imprinted genes (6, 7, 11, 14, 15 and 20), CVS should be considered, followed by amniocentesis if abnormal. If the fetus is unaffected, methylation studies should be considered given the risk of uniparental disomy. A third trimester growth ultrasound should be considered for patients with a positive cfDNA screen for a RAT and an unaffected fetus, especially in the case of trisomy 16. For patients with multiple aneuploidy results on cfDNA, a work-up for maternal malignancy should be considered. CONCLUSIONS: Clinicians should consider rates of CPM, imprinting, ultrasound findings and maternal factors when considering whether to recommend amniocentesis or CVS after an abnormal cfDNA result.

Factors associated with poor outcome in fetuses prenatally diagnosed with sacrococcygeal teratoma.

AIM OF THE STUDY: Outcome of fetuses, prenatally diagnosed with sacrococcygeal teratoma (SCT), is still poorly documented. This study assesses the incidence and prenatal predictors of outcome in all fetuses prenatally diagnosed with SCT. METHODS: This is a retrospective study on all fetuses prenatally diagnosed with SCT from 1998 to 2018 in the Netherlands. Poor outcome was defined as terminations of pregnancy (TOP) because of expected unfavorable outcome, intrauterine fetal death, or early neonatal death. Potential risk factors for poor outcome were analyzed. MAIN RESULTS: Eighty-four fetuses were included. Sixteen (19.0%) TOPs were excluded from statistical analysis. Eleven of the remaining 68 fetuses had poor outcome. Overall mortality was 32.1%, with a mortality excluding TOPs of 13.1%. Thirteen fetal interventions were performed in 11 (13.1%) fetuses. Potential risk factors for poor outcome were the presence of fetal hydrops (OR: 21.0, CI: 2.6-275.1, p = 0.012) and cardiomegaly (OR: 10.3, CI: 1.9-55.8, p = 0.011). CONCLUSIONS: The overall mortality of fetuses prenatally diagnosed with SCTs including tTOP was 32.1%. This high mortality rate was mainly due to termination of pregnancy. Mortality excluding TOP was 13.1%. Potential risk factors for poor outcome were fetal hydrops and cardiomegaly.

Long-term outcomes in children with absent pulmonary valve syndrome: it is not just fixing the heart.

OBJECTIVE: Absent pulmonary valve syndrome (APV) is a rare condition usually associated with tetralogy of Fallot (TOF). Some infants develop respiratory failure from bronchial compression and the long-term neurodevelopmental outcome is unknown. We aimed to investigate the outcomes of APV and the need for long-term ventilation (LTV). DESIGN, PATIENTS AND SETTING: Retrospective single-centre review of patients diagnosed with APV between 2007 and 2017. OUTCOME MEASURES: Survival, neurological disability and postoperative LTV (≥3 months of non-invasive or invasive respiratory support). RESULTS: Thirty patients were identified, 22 (73%) of whom were prenatally diagnosed. Pregnancy was discontinued in one patient, while in utero death occurred in three. One was lost to follow-up. Of the remaining 25 liveborn, 21 had the classic TOF/APV. One baby died immediately after birth, while two patients had palliative care due to severe airway compression and inability to wean ventilation support. Surgical repair was performed in 21 of the 25 (84%) liveborn, with one awaiting surgery. Of those undergoing surgery, two patients died: one during surgery and the other due to severe airway malacia 5 months postsurgery. In the surgical group survival from birth at 1 and 5 years was 89% (95% CI 75% to 100%). Six (30%) patients required LTV postoperatively; all had surgery within the first 6 months of life. Learning and/or other physical difficulties were evident in 63%. CONCLUSIONS: Majority of patients with APV are diagnosed antenatally. A third of those operated required LTV and over half had learning and/or other physical difficulties. Prospective studies are needed to identify prenatal factors that predict postnatal outcomes so parents can be counselled appropriately.

Making the most of the first prenatal visit: The challenge of expanding prenatal genetic testing options and limited clinical encounter time.

OBJECTIVE: Advances in prenatal genetics place additional challenges as patients must receive information about a growing array of screening and testing options. This raises concerns about how to achieve a shared decision-making process that prepares patients to make an informed decision about their choices about prenatal genetic screening and testing options, calling for a reconsideration of how healthcare providers approach the first prenatal visit. METHODS: We conducted interviews with 40 pregnant women to identify components of decision-making regarding prenatal genetic screens and tests at this visit. Analysis was approached using grounded theory. RESULTS: Participants brought distinct notions of risk to the visit, including skewed perceptions of baseline risk for a fetal genetic condition and the implications of screening and testing. Participants were very concerned about financial considerations associated with these options, ranking out-of-pocket costs on par with medical considerations. Participants noted diverging priorities at the first visit from those of their healthcare provider, leading to barriers to shared decision-making regarding screening and testing during this visit. CONCLUSION: Research is needed to determine how to restructure the initiation of prenatal care in a way that best positions patients to make informed decisions about prenatal genetic screens and tests.

Estimating the risk of gestational diabetes mellitus based on the 2013 WHO criteria: a prediction model based on clinical and biochemical variables in early pregnancy.

AIMS: We aimed to develop a prediction model based on clinical and biochemical variables for gestational diabetes mellitus (GDM) based on the 2013 World Health Organization (WHO) criteria. METHODS: A total of 1843 women from a Belgian multi-centric prospective cohort study underwent universal screening for GDM. Using multivariable logistic regression analysis, a model to predict GDM was developed based on variables from early pregnancy. The performance of the model was assessed by receiver-operating characteristic (AUC) analysis. To account for over-optimism, an eightfold cross-validation was performed. The accuracy was compared with two validated models (van Leeuwen and Teede). RESULTS: A history with a first degree relative with diabetes, a history of smoking before pregnancy, a history of GDM, Asian origin, age, height and BMI were independent predictors for GDM with an AUC of 0.72 [95% confidence interval (CI) 0.69-0.76)]; after cross-validation, the AUC was 0.68 (95% CI 0.64-0.72). Adding biochemical variables, a history of a first degree relative with diabetes, a history of GDM, non-Caucasian origin, age, height, weight, fasting plasma glucose, triglycerides and HbA1c were independent predictors for GDM, with an AUC of the model of 0.76 (95% CI 0.72-0.79); after cross-validation, the AUC was 0.72 (95% CI 0.66-0.78), compared to an AUC of 0.67 (95% CI 0.63-0.71) using the van Leeuwen model and an AUC of 0.66 (95% CI 0.62-0.70) using the Teede model. CONCLUSIONS: A model based on easy to use variables in early pregnancy has a moderate accuracy to predict GDM based on the 2013 WHO criteria.

Laboratory screening and diagnosis of open neural tube defects, 2019 revision: a technical standard of the American College of Medical Genetics and Genomics (ACMG).

Open neural tube defects (ONTDs) include open spina bifida (OSB) and anencephaly. These defects are caused by incomplete closure of the neural tube at about 4 weeks of pregnancy. Levels of early second-trimester maternal serum (ms) alpha-fetoprotein (AFP) are sufficiently elevated in affected pregnancies to be used as a population-based screening test. The basic screening methodology was described in the late 1970s and screening programs were active a few years later. By identifying pregnancies with the highest msAFP levels, about 80% of OSB and 95% of anencephaly can be identified as early as 16 weeks gestation. The interpretation of msAFP levels is complicated by the need to consider multiple factors such as gestational age, maternal weight, maternal race, multiple gestations, and more. Testing for AFP and acetylcholinesterase in amniotic fluid and/or identification of the lesion by targeted ultrasound is considered diagnostic of ONTD. When a diagnosis is made, options include termination, surgery after delivery, or in utero surgery, depending on factors such as location and size of the defect, and the presence of any additional anomalies. Screening for ONTD should be performed as part of a comprehensive program linking primary obstetrical care providers, laboratorians, and high-risk clinicians.

Antenatal ultrasound compared to MRI evaluation of fetal myelomeningocele: a prenatal and postnatal evaluation.

Background Spina bifida affects 0.5-1 in 1000 pregnancies in the United States and is often diagnosed in the mid-second trimester. The objective of the study was to directly compare ultrasounds (US) and magnetic resonance imaging (MRI) obtained in the antenatal period in the diagnosis and localization of fetal myelomeningocele (MMC) and compare these with the postnatal outcomes of these infants Methods A retrospective analysis of patients referred to the Fetal Care Center at the Cleveland Clinic from 2005 to 2017. US and MRIs were obtained from the Cleveland Clinic electronic medical record. Infants were followed-up at an interdisciplinary myelomeningocele pediatrics clinic. Results MRI and US varied in correlation with physical exam at the time of birth and surgery. While no differences were detected in demographics, pregnancy outcomes or pediatric outcomes, it was noted that the majority of patients developed neurogenic bladders irrespective of the lesion level. Conclusion MRI is not superior to US in the diagnosis of MMC. Pregnancies complicated by MMC do not vary in morbidity, and pediatric outcomes remain similar regardless of the lesion level. This data provides additional information for the counseling of patients when faced with this antenatal diagnosis.

Hypothyroidism in Pregnancy.

Thyroid hormone is essential for pregnancy and ensuring fetal development. Pregnancy also places substantial demands on the thyroid axis. Overt hypothyroidism is associated with substantial adverse obstetric and offspring outcomes and requires treatment. Borderline thyroid dysfunction is common in women and associated with adverse obstetric and offspring outcomes, although benefits of screening for and treating borderline thyroid function are unclear. Many women are established on thyroid hormone replacement before pregnancy and doses need increasing during pregnancy. Care is taken to prevent overreplacement. Universal thyroid screening in pregnancy is being undertaken in several countries, although it remains a matter of debate.

Error traps and culture of safety in the treatment of abdominal wall defects.

The importance of defining and implementing a culture of safety in pediatric surgery is being increasingly seen as essential to decreasing complications and improving outcomes. The concept of a safety culture is a universal one, but the elements of such a culture are different for every disease and anomaly treated. In this paper, I will review these elements as they pertain to the treatment of abdominal wall defects starting from fetal evaluation to post-discharge care.

No. 383-Screening, Diagnosis, and Management of Placenta Accreta Spectrum Disorders.

BACKGROUND: Placenta accreta spectrum (PAS) disorders are a potentially life-threatening complication of pregnancy that demand coordinated interdisciplinary care to achieve safer outcomes. The rising incidence of this disease is due to a growing number of uterine surgical procedures, including the rising incidence of pregnancy following Caesarean section. OBJECTIVE: To provide current evidence-based guidelines on the optimal methods used to effectively screen, diagnose, and manage PAS disorders. METHODS: Members of the guideline committee were selected on the basis of their ongoing expertise in managing this condition across Canada and by practice setting. The committee reviewed all available evidence in the English medical literature, including published guidelines, and evaluated diagnostic tests, surgical procedures, and clinical outcomes. EVIDENCE: Published literature, including clinical practice guidelines, was retrieved through searches of Medline and The Cochrane Library to March 2018 using appropriate controlled vocabulary and key words. Results were restricted to systematic reviews, randomized controlled trials, and observational studies written in English. Searches were updated on a regular basis and incorporated in the guideline to July 2018. VALUES: The quality of evidence in this document was graded using the criteria described in the Report of the Canadian Task Force on Preventive Health Care. RESULTS: This document reviews the evidence regarding the available diagnostic and surgical techniques used for optimal management of women with suspected PAS disorders, including anaesthesia and practical considerations for interdisciplinary care. BENEFITS, HARMS, AND COSTS: Implementation of the guideline recommendations will improve awareness of this disease and increase the proportion of affected women receiving interdisciplinary care in regional centres. CONCLUSIONS: Interdisciplinary team-based care providing accurate diagnostic services, coordinated planning, and safer surgery deliver effective care with improved clinical outcomes in comparison with alternative management. SUMMARY STATEMENTS: RECOMMENDATIONS.

Fetal dynamic phase-contrast MR angiography using ultrasound gating and comparison with Doppler ultrasound measurements.

OBJECTIVES: To investigate the feasibility of fetal phase-contrast (PC)-MR angiography of the descending aorta (AoD) using an MR-compatible Doppler ultrasound sensor (DUS) for fetal cardiac gating and to compare velocimetry with Doppler ultrasound measurements. METHODS: In this prospective study, 2D PC-MR angiography was performed in 12 human fetuses (mean gestational age 32.8 weeks) using an MR-compatible DUS for gating of the fetal heart at 1.5 T. Peak flow velocities in the fetal AoD were compared with Doppler ultrasound measurements performed on the same day. Reproducibility of PC-MR measurements was tested by repeated PC-MR in five fetuses. RESULTS: Dynamic PC-MR angiography in the AoD was successfully performed in all fetuses using the DUS, with an average fetal heart rate of 140 bpm (range 129-163). Time-velocity curves revealed typical arterial blood flow patterns. PC-MR mean flow velocity and mean flux were 21.2 cm/s (range 8.6-36.8) and 8.4 ml/s (range 3.2-14.6), respectively. A positive association between PC-MR mean flux and stroke volume with gestational age was obtained (r = 0.66, p = 0.02 and r = 0.63, p = 0.03). PC-MR and Doppler ultrasound peak velocities revealed a highly significant correlation (r = 0.8, p < 0.002). Peak velocities were lower for PC-MR with 69.1 cm/s (range 39-125) compared with 96.7 cm/s (range 60-142) for Doppler ultrasound (p < 0.001). Reproducibility of PC-MR was high (p > 0.05). CONCLUSION: The MR-compatible DUS for fetal cardiac gating allows for PC-MR angiography in the fetal AoD. Comparison with Doppler ultrasound revealed a highly significant correlation of peak velocities with underestimation of PC-MR velocities. This new technique for direct fetal cardiac gating indicates the potential of PC-MR angiography for assessing fetal hemodynamics. KEY POINTS: • The developed MR-compatible Doppler ultrasound sensor allows direct fetal cardiac gating and can be used for prenatal dynamic cardiovascular MRI. • The MR-compatible Doppler ultrasound sensor was successfully applied to perform intrauterine phase-contrast MR angiography of the fetal aorta, which revealed a highly significant correlation with Doppler ultrasound measurements. • As fetal flow hemodynamics is an important parameter in the diagnosis and management of fetal pathologies, fetal phase-contrast MR angiography may offer an alternative imaging method in addition to Doppler ultrasound and develop as a second line tool in the evaluation of fetal flow hemodynamics.

Prenatal therapy for fetal cardiac disorders.

Fetal cardiac abnormalities are some of the commonest congenital disorders seen in prenatal life. They can be anatomical or functional and can develop de novo or as a consequence of either maternal or fetal disease. Untreated, morbidity and mortality rates are high for hypoplastic left heart disorders and for some fetal tachy and bradyarrhythmias. Optimum management strategies are often not clear because of the lack of knowledge about the precise natural history of some of these conditions. Prenatal therapy ranges from invasive fetal cardiac intervention to maternal administration of drugs for transplacental transfer to the fetus. This comprehensive review covers many fetal cardiac disorders and various prenatal therapeutic options that are available.

Fourth ventricle index: sonographic marker for severe fetal vermian dysgenesis/agenesis.

OBJECTIVE: Prenatal diagnosis of midbrain-hindbrain (MB-HB) malformations relies primarily on abnormal size and shape of the cerebellum and retrocerebellar space, particularly 'open fourth ventricle' (4V), the most common indicator of MB-HB malformations. The aim of this study was to present the fourth ventricle index (4VI), and to evaluate its role as a marker for severe vermian dysgenesis/agenesis in cases without open 4V. METHODS: This was a prospective cross-sectional study of patients with singleton low-risk pregnancy at 14 + 1 to 36 + 6 gestational weeks presenting between May 2016 and November 2017 for routine ultrasound examination. Axial images of the fetal 4V were obtained and the 4VI was calculated as the ratio between the laterolateral and the anteroposterior diameters. Reference ranges were constructed and retrospectively collected values from 44 fetuses with confirmed anomalies involving severe vermian dysgenesis/agenesis (Joubert syndrome and related disorders, rhombencephalosynapsis, cobblestone malformations and cerebellar hypoplasia) but without open 4V were compared with the normal values. RESULTS: In total, 384 healthy fetuses were enrolled into the study, from which reference ranges were produced, and 44 cases were collected retrospectively. The 4VI in the normal fetuses was always > 1. In affected fetuses, it was always below mean -2 SD and < 1. CONCLUSIONS: The 4VI is a sonographic marker for severe fetal vermian dysgenesis/agenesis in the absence of an open 4V. It may be incorporated easily into the routine brain scan; 4VI < 1 indicates a need for dedicated fetal neuroimaging for diagnosis and prenatal counseling. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Prenatal echocardiographic assessment of right aortic arch.

OBJECTIVES: To report our experience with fetal diagnosis of right aortic arch (RAA) variants based on the ductus arteriosus (DA) anatomy and brachiocephalic vessel branching pattern in relation to the trachea, and to establish whether the echocardiographic 'V-shaped' or 'U-shaped' appearance of the junction between the DA and aortic arch (AA) in the fetal upper mediastinal view is sufficiently accurate for assessment of fetal AA anatomy. METHODS: This was a retrospective study of pregnancies with a prenatal diagnosis of fetal RAA that had postnatal confirmation of AA anatomy, referred to our tertiary center during 2011-2017. Prenatal and postnatal medical records, including echocardiographic and computed tomography (CT)/magnetic resonance imaging (MRI) scan reports, were reviewed, and cardiac and extracardiac abnormalities and the results of genetic testing were recorded. RESULTS: Of 55 consecutive pregnancies with a prenatal diagnosis of fetal RAA, six were lost to follow-up, one was terminated and three were excluded due to lack of postnatal confirmation of AA anatomy. Of the remaining 45 pregnancies, AA anatomy was assessed postnatally by CT in 39, by MRI in one and by direct examination at cardiac surgery in five. A U-shaped appearance was found in 37/45 (82.2%) patients, all of which had a complete vascular ring (CVR). Of these 37 patients, on postnatal confirmation, 21 (56.8%) had RAA with Kommerell's diverticulum, left posterior ductus arteriosus (LPDA) and aberrant left subclavian artery (ALSA) (RAA/LPDA/ALSA), 11 (29.7%) had a double AA (DAA), four (10.8%) had RAA with Kommerell's diverticulum, LPDA and mirror-image (MI) branching (RAA/LPDA/MI), and one (2.7%) had RAA with Kommerell's diverticulum, LPDA and aberrant left innominate artery (ALIA) (RAA/LPDA/ALIA). A V-shaped appearance was found in 3/45 (6.7%) patients, all of which had RAA with right DA not forming a CVR and MI branching. In the 5/45 (11.1%) fetuses with neither U- nor V-shaped appearance, RAA with left anterior DA arising from the left innominate artery and MI branching, not forming a CVR, was found. Twelve (26.7%) fetuses had a congenital heart defect (CHD). RAA forming a CVR (U-shaped appearance) was associated with a septal defect in 6/37 (16.2%) fetuses, while RAA not forming a CVR (V-shaped appearance or no U- or V-shaped appearance) was associated with major CHD in 6/8 (75.0%) fetuses. CONCLUSIONS: In fetuses with RAA, V-shaped appearance of the junction between the DA and AA indicates only that the transverse AA and DA run together on the same side of the thorax (trachea) while a U-shaped appearance is always a sign of a CVR. Among fetuses with a CVR, RAA/LPDA/MI is more frequent than described previously. Finally, RAA forming a CVR is not usually associated with complex CHD, as opposed to RAA not forming a CVR. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

The implementation of a nationwide anomaly screening programme improves prenatal detection of major cardiac defects: an 11-year national population-based cohort study.

OBJECTIVE: To evaluate whether a nationwide prenatal anomaly screening programme improves detection rates of univentricular heart (UVH) and transposition of great arteries (TGA), and whether maternal risk factors for severe fetal heart disease affect prenatal detection. DESIGN: Population-based cohort study. SETTING: Nationwide data from Finnish registries 2004-14. POPULATION: A total of 642 456 parturients and 3449 terminated pregnancies due to severe fetal anomaly. METHODS: Prenatal detection rates were calculated in three time periods (prescreening, transition and screening phase). The effect of maternal risk factors (obesity, in vitro fertilisation, pregestational diabetes and smoking) was evaluated. MAIN OUTCOME MEASURES: Change in detection rates and impact of maternal risk factors on screening programme efficacy. RESULTS: In total, 483 cases of UVH and 184 of TGA were detected. The prenatal detection rate of UVH increased from 50.4% to 82.8% and of TGA from 12.3% to 41.0% (P < 0.0001). Maternal risk factors did not affect prenatal detection rate, but detection rate differed substantially by region. CONCLUSIONS: A nationwide screening programme improved overall UVH and TGA detection rates, but regional differences were observed. Obesity or other maternal risk factors did not affect the screening programme efficacy. The establishment of structured guidelines and recommendations is essential when implementing the screening programme. In addition, a prospective screening register is highly recommended to ensure high quality of screening. TWEETABLE ABSTRACT: Implementation of a nationwide prenatal anomaly screening improved detection rates of UVH and TGA.

Selective screening for thyroid dysfunction in pregnant women: How often do low-risk women cease to be treated following the new guidelines of the American Thyroid Association?

ABSTRACT Objective: Universal screening for thyroid dysfunction in pregnant women is not recommended by the American Thyroid Association (ATA) or the American Association of Clinical Endocrinologists (AACE). This study evaluated the frequency of pregnant women that would have an indication for levothyroxine (L-T4) according to the new ATA/AACE guidelines among low-risk women without an indication for screening with TSH. Subjects and methods: The sample consisted of 412 pregnant women ranging in age from 18 to 30 years. These women were considered to be at low risk for thyroid dysfunction according to ATA/AACE and would not be candidates for screening with TSH. Anti-thyroid peroxidase antibodies (TPOAb) and TSH were measured. Women who had TSH > 2.5 mIU/L or TPOAb in the first trimester were submitted to subsequent evaluations in the second and third trimester. Results: In the first trimester, none of the pregnant women would have L-T4 therapy "recommended" and treatment would be "considered" in only two. In the second trimester, pregnant women with positive TPOAb or TSH > 2.5 mIU/L in the first trimester (n = 30) were reevaluated. L-T4 treatment would be "recommended" in only one woman and would be "considered" in two others. The 28 women that were not treated in the second trimester were reevaluated in the third trimester, but none of them would have L-T4 "recommended". Conclusion: The findings of the study suggest that selective screening, recommended by ATA/AACE does not result in a significant loss of pregnant women with an indication for L-T4 treatment.