A Sequential Multiple Assignment Randomized Trial (SMART) study of medication and CBT sequencing in the treatment of pediatric anxiety disorders.

BACKGROUND: Treatment of a child who has an anxiety disorder usually begins with the question of which treatment to start first, medication or psychotherapy. Both have strong empirical support, but few studies have compared their effectiveness head-to-head, and none has investigated what to do if the treatment tried first isn't working well-whether to optimize the treatment already begun or to add the other treatment. METHODS: This is a single-blind Sequential Multiple Assignment Randomized Trial (SMART) of 24 weeks duration with two levels of randomization, one in each of two 12-week stages. In Stage 1, children will be randomized to fluoxetine or Coping Cat Cognitive Behavioral Therapy (CBT). In Stage 2, remitters will continue maintenance-level therapy with the single-modality treatment received in Stage 1. Non-remitters during the first 12 weeks of treatment will be randomized to either [1] optimization of their Stage 1 treatment, or [2] optimization of Stage 1 treatment and addition of the other intervention. After the 24-week trial, we will follow participants during open, naturalistic treatment to assess the durability of study treatment effects. Patients, 8-17 years of age who are diagnosed with an anxiety disorder, will be recruited and treated within 9 large clinical sites throughout greater Los Angeles. They will be predominantly underserved, ethnic minorities. The primary outcome measure will be the self-report score on the 41-item youth SCARED (Screen for Child Anxiety Related Disorders). An intent-to-treat analysis will compare youth randomized to fluoxetine first versus those randomized to CBT first ("Main Effect 1"). Then, among Stage 1 non-remitters, we will compare non-remitters randomized to optimization of their Stage 1 monotherapy versus non-remitters randomized to combination treatment ("Main Effect 2"). The interaction of these main effects will assess whether one of the 4 treatment sequences (CBT➔CBT; CBT➔med; med➔med; med➔CBT) in non-remitters is significantly better or worse than predicted from main effects alone. DISCUSSION: Findings from this SMART study will identify treatment sequences that optimize outcomes in ethnically diverse pediatric patients from underserved low- and middle-income households who have anxiety disorders. TRIAL REGISTRATION: This protocol, version 1.0, was registered in ClinicalTrials.gov on February 17, 2021 with Identifier: NCT04760275 .

Validity of the Montreal Cognitive Assessment Screener in Adolescents and Young Adults With and Without Congenital Heart Disease.

BACKGROUND: Cognitive deficits are common, long-term sequelae in children and adolescents with congenital heart disease (CHD) who have undergone surgical palliation. However, there is a lack of a validated brief cognitive screening tool appropriate for the outpatient setting for adolescents with CHD. One candidate instrument is the Montreal Cognitive Assessment (MoCA) questionnaire. OBJECTIVE: The purpose of the research was to validate scores from the MoCA against the General Memory Index (GMI) of the Wide Range Assessment of Memory and Learning, 2nd Edition (WRAML2), a widely accepted measure of cognition/memory, in adolescents and young adults with CHD. METHODS: We administered the MoCA and the WRAML2 to 156 adolescents and young adults ages 14-21 (80 youth with CHD and 76 healthy controls who were gender and age matched). Spearman's rank order correlations were used to assess concurrent validity. To assess construct validity, the Mann-Whitney U test was used to compare differences in scores in youth with CHD and the healthy control group. Receiver operating characteristic curves were created and area under the curve, sensitivity, specificity, positive predictive value, and negative predictive value were also calculated. RESULTS: The MoCA median scores in the CHD versus healthy controls were (23, range 15-29 vs. 28, range 22-30; p < .001), respectively. With the screening cutoff scores at <26 points for the MoCA and 85 for GMI (<1 SD, M = 100, SD = 15), the CHD versus healthy control groups showed sensitivity of .96 and specificity of .67 versus sensitivity of .75 and specificity of .90, respectively, in the detection of cognitive deficits. A cutoff score of 26 on the MoCA was optimal in the CHD group; a cutoff of 25 had similar properties except for a lower negative predictive value. The area under the receiver operating characteristic curve (95% CI) for the MoCA was 0.84 (95% CI [0.75, 0.93], p < .001) and 0.84 (95% CI [0.62, 1.00], p = .02) for the CHD and controls, respectively. DISCUSSION: Scores on the MoCA were valid for screening to detect cognitive deficits in adolescents and young adults aged 14-21 with CHD when a cutoff score of 26 is used to differentiate youth with and without significant cognitive impairment. Future studies are needed in other adolescent disease groups with known cognitive deficits and healthy populations to explore the generalizability of validity of MoCA scores in adolescents and young adults.

Unique system of care issues and challenges in serving children under age 3 and their families.

This article addresses the primary modifications necessary for system change to better meet the mental health needs of children under the age of three. The role of risk and resiliency factors in the young child, family and community and the necessity for a comprehensive community infant-family mental health system with a focus on the whole family are addressed. Barriers to care within early childhood systems of care are examined, including stigma, community referral and collaboration, diagnostic concerns during infancy, issues around family engagement, empowerment and partnership, funding of comprehensive and well coordinated infant-family services, workforce capacity and evaluation. Recommendations for implementation of system changes at the community and federal levels are proposed.

von Hippel-Lindau disease: surveillance strategy for endolymphatic sac tumors.

PURPOSE: : Up to 16% of patients with the hereditary von Hippel-Lindau disease develop endolymphatic sac tumors of the inner ear. Early diagnosis and treatment of endolymphatic sac tumors can prevent audiovestibular morbidity, but optimal endolymphatic sac tumor surveillance strategy has yet to be determined. We aimed to evaluate endolymphatic sac tumor surveillance to determine the best surveillance strategy. METHODS: : In a national prospective study, 40 VHL mutation carriers were interviewed about audiovestibular symptoms and had audiological examinations and magnetic resonance imaging of the inner ear. Further, we performed a meta-analysis including all reported endolymphatic sac tumor von Hippel-Lindau disease cases in the literature (N = 140 with 156 endolymphatic sac tumors). RESULTS: : In the prospective study, endolymphatic sac tumors were suspected based on audiovestibular symptoms, audiometry, and magnetic resonance imaging in 34%, 30%, and 12.5% of subjects, respectively. In total, more than 90% of radiologically diagnosed endolymphatic sac tumors were associated with abnormal audiometric findings. No endolymphatic sac tumor genotype-phenotype correlations were found. CONCLUSION: : We recommend annual audiometry as a first-line endolymphatic sac tumor screening tool, and in countries where periodic surveillance magnetic resonance imaging of the central nervous system is performed, specific images of the inner ear should be included. Audiometric abnormalities in patients with von Hippel-Lindau disease without magnetic resonance imaging-visible endolymphatic sac tumors could be due to microscopic endolymphatic sac tumors. Determination of audiometric endolymphatic sac tumor characteristics could further target screening and improve endolymphatic sac tumor diagnosis.

Mosaicism in segmental Darier disease: an in-depth molecular analysis quantifying proportions of mutated alleles in various tissues.

Darier disease is an autosomal dominant genodermatosis caused by germline mutations in the ATP2A2 gene. Clinical expression is variable, including rare segmental phenotypes thought to be caused by postzygotic mosaicism. Genetic counseling of segmental Darier patients is complex, as risk of transmitting a nonsegmental phenotype to offspring is of unknown magnitude. We present the first in-depth molecular analysis of a mosaic patient with segmental disease, quantifying proportions of mutated and normal alleles in various tissues. Pyrosequence analysis of DNA from semen, affected and normal skin, peripheral leukocytes and hair revealed an uneven distribution of the mutated allele, from 14% in semen to 37% in affected skin. We suggest a model for segmental manifestation expression where a threshold number of mutated cells is needed for manifestation development. We further recommend molecular analysis of the ATP2A2 gene in semen of male patients with segmental Darier disease to improve genetic counseling.

Policy and Practice Barriers to Early Identification of Autism Spectrum Disorder in the California Early Intervention System.

Autism spectrum disorder can be reliably diagnosed prior to age 2, and early, intensive intervention has been found to improve long-term outcomes. Nonetheless, most children with ASD do not receive a diagnosis until after age 3, with even later diagnoses for children from non-white ethnic groups. This study conducted telephone surveys with California Part C early intervention managers regarding policies and practices for early identification and intervention for ASD. Findings indicated that 85% of agencies conduct screening for ASD, but only 39% conduct ASD diagnostic assessments prior to age 3. Recommendations for policy changes to align Part C practices with best practice guidelines are provided.

Placental transfer of pesticides studied in human placental perfusion.

To investigate the transplacental transport of pesticides, the pyrethroid cypermethrin and the fungicide azoles, propiconazole and bitertanol were tested in the placental perfusion model. Cypermethrin, propiconazole and bitertanol were also tested in the BeWo cell transfer model. The pesticides were chosen with the selection criteria: use in Denmark, significant treated areas and knowledge on hormone-disrupting effects. Propiconazole and bitertanol showed rapid transfer and adsorbance to the system in both placental perfusion and BeWo cell system, whereas cypermethrin had a slower transport across the placental cell layers in the two models. There was no difference between data of the single pesticides and their mixture in either placental perfusion or BeWo cell transfer model. Both the placental perfusion model and the BeWo cell model metabolized the pesticides and released metabolites into both foetal and maternal circulation. Using human exposure models, this study shows the potential exposure of the human foetus to pesticides cypermethrin, propiconazole and bitertanol and their metabolites.

Human milk oligosaccharide 2'-fucosyllactose links feedings at 1 month to cognitive development at 24 months in infants of normal and overweight mothers.

BACKGROUND: Infant cognitive development is influenced by maternal factors that range from obesity to early feeding and breast milk composition. Animal studies suggest a role for human milk oligosaccharide (HMO), 2'-fucosyllactose (2'FL), on learning and memory, yet no human studies have examined its impact on infant cognitive development relative to other HMOs and maternal factors. OBJECTIVE: To determine the impact of 2'FL from breast milk feeding on infant cognitive development at 24 months of age relative to maternal obesity and breast milk feeding frequency. METHODS AND MATERIALS: Hispanic mother-infant pairs (N = 50) were recruited across the spectrum of pre-pregnancy BMI. Breast milk was collected at 1 and 6 months, and feedings/day were reported. Nineteen HMOs were analyzed using high-performance liquid chromatography, with initial interest in 2'FL. Infant cognitive development score was assessed with the Bayley-III Scale at 24 months. Linear regressions were used for prediction, and bootstrapping to determine mediation by 2'FL. RESULTS: Maternal pre-pregnancy BMI was not related to feedings/day or HMOs, but predicted poorer infant cognitive development (ß = -0.31, P = 0.03). Feedings/day (ß = 0.34) and 2'FL (ß = 0.59) at 1 month predicted better infant cognitive development (both P≤ 0.01). The association of feedings/day with infant cognitive development was no longer significant after further adjustment for 2'FL (estimated mediation effect = 0.13, P = 0.04). There were no associations of feedings/day and 2'FL at 6 months with infant cognitive development. CONCLUSIONS: Our findings suggest that maternal factors influence infant cognitive development through multiple means. Though maternal obesity may be a separate negative influence, greater frequency of breast milk feeding at 1 month contributed to infant cognitive development through greater exposure to 2'FL relative to other HMOs. The influence of 2'FL was not significant at 6 months, indicating that early exposure to 2'FL may be a critical temporal window for positively influencing infant cognitive development.

Airway exposure to TiO2 nanoparticles and quartz and effects on sperm counts and testosterone levels in male mice.

Several types of engineered nanoparticles (ENP) have been shown to adversely affect male reproduction in rodent studies, but the airway route of exposure has been little investigated. This precludes adequate risk assessment of ENP exposure in occupational settings. Titanium dioxide nanoparticles (TiO2 NP) have been shown to affect total sperm count in adult male mice after intravenous and oral administration. This study aimed to investigate whether also airway exposure would affect sperm counts in male mice. Mature C57BL/6J mice were intratracheally instilled with 63 µg of rutile nanosized TiO2, once weekly for seven weeks. Respirable α-quartz (SRM1878a) was included at a similar dose level as a positive control for pulmonary inflammation. BALF cell composition showed neutrophil granulocyte influx as indication of pulmonary inflammation in animals exposed to TiO2 NP and α-quartz, but none of the particle exposures affected weight of testes or the epididymis, sperm counts or plasma testosterone when assessed at termination of the study.

Broad Developmental Screening Misses Young Children With Social-Emotional Needs.

Many pediatricians use a broad developmental screening test as part of well-child care, but do not specifically screen for behavioral and emotional disorders. Parents at 2 urban community agencies completed both the Ages and Stages Questionnaire (ASQ-3) and the Ages and Stages Questionnaire: Social Emotional (ASQ:SE) for 608 children, ages 2 to 60 months; 51.8% in Spanish. Less than half of the children with a positive screen on the ASQ:SE would have been identified as needing additional assessment or intervention if only the ASQ-3 had been administered. Younger children with positive ASQ:SE screens were significantly less likely to be referred for mental health services compared with older children. Physicians should consider screening all young children for social-emotional and behavioral needs, and referring those identified for infant and early childhood mental health services.

Feasibility of expanding services for very young children in the public mental health setting.

OBJECTIVE: A quality-improvement study evaluated the feasibility of training mental health providers to provide mental health screening and relationship-based intervention to expand services for children 0 to 5 years of age in eight California county mental health systems from November 2002 to June 2003. State-level training was provided to more than 582 participants and county-level training to more than 5425 participants, including ongoing supervision. METHOD: Direct services and use of collateral services were tracked. Psychiatric symptoms were screened with new Mental Health Screening and Risk Assessment tools for 388 children (mean age, 34 months). At intake and after intervention (mean of 22 visits), an index sample (93 children) were further characterized by the Diagnostic Classification for Zero to Three and DSM-IV, and parent-child relationship was characterized by the Diagnostic Classification for Zero to Three Parent-Infant Relationship Global Assessment Scale. Providers reported that 41% of their service time was directed to the parent and child together, 35% to the parent alone, and 24% to the child alone. RESULTS: The 93 index children and 295 children in a clinic reference sample were comparable, supporting generalizability. After intervention, Mental Health Screening and Risk Assessment scores were significantly lower. Global Assessment of Functioning scores improved (effect size, 0.35), as did the relationship (Parent-Infant Relationship Global Assessment Scale effect size, 0.16). CONCLUSION: Training mental health staff to provide treatment to infants and preschool children and families in public mental health settings is feasible and leads to an increase in numbers of children served.

A Prospective Study of the Concordance of DSM-IV and DSM-5 Diagnostic Criteria for Autism Spectrum Disorder.

The transition from DSM-IV to DSM-5 criteria for autism spectrum disorder (ASD) sparked considerable concern about the potential implications of these changes. This study was designed to address limitations of prior studies by prospectively examining the concordance of DSM-IV and final DSM-5 criteria on a consecutive sample of 439 children referred for autism diagnostic evaluations. Concordance and discordance were assessed using a consistent diagnostic battery. DSM-5 criteria demonstrated excellent overall specificity and good sensitivity relative to DSM-IV criteria. Sensitivity and specificity were strongest for children meeting DSM-IV criteria for autistic disorder, but poor for those meeting criteria for Asperger's disorder and pervasive developmental disorder. Higher IQ, older age, female sex, and less pronounced ASD symptoms were associated with greater discordance.

Predictors of Memory Deficits in Adolescents and Young Adults with Congenital Heart Disease Compared to Healthy Controls.

INTRODUCTION: Adolescents and young adults with congenital heart disease (CHD) show a range of memory deficits, which can dramatically impact their clinical outcomes and quality of life. However, few studies have identified predictors of these memory changes. The purpose of this investigation was to identify predictors of memory deficits in adolescents and young adults with CHD after surgical palliation compared to healthy controls. METHOD: One hundred fifty-six adolescents and young adults (80 CHD and 76 controls; age 14-21 years) were recruited and administered an instrument to assess memory [Wide Range Assessment of Memory and Learning Second Edition - general memory index (GMI) score] and completed questionnaires that measure anxiety, depression, sleepiness, health status, and self-efficacy. Descriptive and non-parametric statistics were used to assess group differences, and logistic regression to identify predictors of memory deficits. RESULTS: CHD subjects consisted of 58% males, median age 17 years, 43% Hispanic, and medians of 2 previous heart surgeries and 14 years since last surgery. Memory deficits (GMI ≤ 85) were identified in 50% CHD compared to 4% healthy controls (median GMI 85 vs. 104, p < 0.001). Of GMI subscale medians, CHD subjects had significantly worse memory performance vs. healthy controls (verbal 88 vs. 105, p < 0.001; attention 88 vs. 109, p < 0.001; working memory 86 vs. 108, p < 0.001). No significant differences appeared between groups for visual memory. Multiple clinical and psychosocial factors were identified which were statistically different on bivariate analyses between the subjects with and without memory deficits. By multivariate analysis, male gender, number of surgeries, anxiety, and self-efficacy emerged as independent predictors of memory deficits. CONCLUSION: Adolescents and young adults with CHD, more than a decade since their last surgery, show significant verbal, attention, and working memory deficits over controls. To enhance patient memory/self-care, clinicians should explore ways to reduce anxiety, improve self-efficacy, and increase use of visual patient education material, especially in CHD males.

Kinetics of silica nanoparticles in the human placenta.

The potential medical applications of nanoparticles (NPs) warrant their investigation in terms of biodistribution and safety during pregnancy. The transport of silica NPs across the placenta was investigated using two models of maternal-foetal transfer in human placenta, namely, the BeWo b30 choriocarcinoma cell line and the ex vivo perfused human placenta. Nanotoxicity in BeWo cells was examined by the MTT assay which demonstrated decreased cell viability at concentrations >100 µg/mL. In the placental perfusion experiments, antipyrine crossed the placenta rapidly, with a foetal:maternal ratio of 0.97 ± 0.10 after 2 h. In contrast, the percentage of silica NPs reaching the foetal perfusate after 6 h was limited to 4.2 ± 4.9% and 4.6 ± 2.4% for 25 and 50 nm NPs, respectively. The transport of silica NPs across the BeWo cells was also limited, with an apparent permeability of only 1.54 × 10(-6) ± 1.56 × 10(-6) cm/s. Using confocal microscopy, there was visual confirmation of particle accumulation in both BeWo cells and in perfused placental tissue. Despite the low transfer of silica NPs to the foetal compartment, questions regarding biocompatibility could limit the application of unmodified silica NPs in biomedical imaging or therapy.

Secondary analysis of primary and preventive services accessed and perceived service barriers by children with developmental disabilities and their families.

Children and youths with developmental disabilities (DD) have needs for more community-based services to address ongoing health, educational, employment, housing, transportation, and recreational concerns. Secondary data analysis was conducted to examine the array of services accessed and service obstacles to primary, preventive and special health care services of 102 children and youths with developmental disabilities. The two services most frequently reported as being used by families were SSI (29.4%) and MediCal (California's Medicaid program) (27.8%). Speech therapy was the most frequently identified support service accessed by respondents (51%). Respondents identified a number of unaddressed concerns and perceived barriers to having these concerns addressed as it related to service referrals for speech therapy, nutrition services, dental services, and behavior management services.

Modelling of human transplacental transport as performed in Copenhagen, Denmark.

Placenta perfusion models are very effective when studying the placental mechanisms in order to extrapolate to real-life situations. The models are most often used to investigate the transport of substances between mother and foetus, including the potential metabolism of these. We have studied the relationships between maternal and foetal exposures to various compounds including pollutants such as polychlorinated biphenyls, polybrominated flame retardants, nanoparticles as well as recombinant human antibodies. The compounds have been studied in the human placenta perfusion model and to some extent in vitro with an established human monolayer trophoblast cell culture model. Results from our studies distinguish placental transport of substances by physicochemical properties, adsorption to placental tissue, binding to transport and receptor proteins and metabolism. We have collected data from different classes of chemicals and nanoparticles for comparisons across chemical structures as well as different test systems. Our test systems are based on human material to bypass the extrapolation from animal data. By combining data from our two test systems, we are able to rank and compare the transport of different classes of substances according to their transport ability. Ultimately, human data including measurements in cord blood contribute to the study of placental transport.

In vitro placental model optimization for nanoparticle transport studies.

BACKGROUND: Advances in biomedical nanotechnology raise hopes in patient populations but may also raise questions regarding biodistribution and biocompatibility, especially during pregnancy. Special consideration must be given to the placenta as a biological barrier because a pregnant woman's exposure to nanoparticles could have significant effects on the fetus developing in the womb. Therefore, the purpose of this study is to optimize an in vitro model for characterizing the transport of nanoparticles across human placental trophoblast cells. METHODS: The growth of BeWo (clone b30) human placental choriocarcinoma cells for nanoparticle transport studies was characterized in terms of optimized Transwell(®) insert type and pore size, the investigation of barrier properties by transmission electron microscopy, tight junction staining, transepithelial electrical resistance, and fluorescein sodium transport. Following the determination of nontoxic concentrations of fluorescent polystyrene nanoparticles, the cellular uptake and transport of 50 nm and 100 nm diameter particles was measured using the in vitro BeWo cell model. RESULTS: Particle size measurements, fluorescence readings, and confocal microscopy indicated both cellular uptake of the fluorescent polystyrene nanoparticles and the transcellular transport of these particles from the apical (maternal) to the basolateral (fetal) compartment. Over the course of 24 hours, the apparent permeability across BeWo cells grown on polycarbonate membranes (3.0 µm pore size) was four times higher for the 50 nm particles compared with the 100 nm particles. CONCLUSION: The BeWo cell line has been optimized and shown to be a valid in vitro model for studying the transplacental transport of nanoparticles. Fluorescent polystyrene nanoparticle transport was size-dependent, as smaller particles reached the basal (fetal) compartment at a higher rate.

How good are clinical severity and outcome measures for psoriasis?: quantitative evaluation in a systematic review.

A large number of clinical measures of psoriasis are used in clinical trials and daily practice. These measures lack uniformity and validation. However, valid outcome and severity measures for psoriasis are a prerequisite for fully informative clinical research and evidence-based medicine. The purpose of this study was to identify all clinical measures of psoriasis severity and outcome in use and to evaluate the quality of these measures using clinimetric criteria; we identified 53 separate clinical measures, which were regrouped into 11 measures for quality analysis. No measure could be scored on all items used in the clinimetric analysis. The Lattice System Physician's Global Assessment and Physician's Global Assessment were most highly noted. We conclude that none of the psoriasis measures is adequately validated. The Psoriasis Area and Severity Index is the most commonly used clinical measure in research, but it has substantial limitations such as low response distribution, no consensus on interpretability, and low responsiveness in mild disease. Nevertheless, because of its widespread use the Psoriasis Area and Severity Index permits some degree of comparison of results among clinical trials. Overall, no best instrument was identified, and different situations may call for different measures.

Otoacoustic emissions: a valid, efficient first-line hearing screen for preschool children.

BACKGROUND: Normal hearing during the preschool years is essential for speech, language, social, emotional, and preacademic development. Children of low socioeconomic status may be particularly vulnerable to the negative effects of late identification and intervention. While a mass-screening effort focused on preschool children does not have broad support, focused screening remains important to identify children at risk. This project was conducted to address 3 primary aims: develop and implement an initial hearing screen using transient evoked otoacoustic emissions (TEOAEs) for at-risk preschoolers, verify speed and tolerability of the screen, and assess the test performance of TEOAEs screening compared to pure tone audiometry in a group of 142 preschool children. METHODS: A total of 744 preschool children attending preschools in an underserved, urban community completed TEOAEs screening by a school nurse. A secondary cohort of 142 children was screened first by TEOAEs and then followed by pure tone audiometry and results compared. RESULTS: A total of 680 children passed screening. Forty-one children (5.5%) had a "refer" result. Two-year-olds had the highest refusal rate (10.5%). Mean testing time was 43 seconds per ear. Secondary cohort analysis revealed 1 subject did not pass either TEOAEs or pure tone screening; no subject passed TEOAEs and then did not pass pure tone audiometry. TEOAEs screening test sensitivity was 1.00 (95% confidence interval 0.054-1.00) and specificity 0.94 (0.88-0.97). CONCLUSIONS: TEOAEs screening performed by school nurses is a fast, efficient, and feasible model. Children who pass TEOAEs screening have a very high likelihood of being free from hearing impairment. Application may be particularly relevant in underserved communities.

Modeling placental transport: correlation of in vitro BeWo cell permeability and ex vivo human placental perfusion.

The placental passage of three compounds with different physicochemical properties was recently investigated in ex vivo human placental perfusion experiments (caffeine, benzoic acid, and glyphosate) [Mose, T., Kjaerstad, M.B., Mathiesen, L., Nielsen, J.B., Edelfors, S., Knudsen, L.E., 2008. Placental passage of benzoic acid, caffeine, and glyphosate in an ex vivo human perfusion system. J. Toxicol. Environ. Health, Part A 71, 984-991]. In this work, the transport of these same three compounds, plus the reference compound antipyrine, was investigated using BeWo (b30) cell monolayers. Transport across the BeWo cells was observed in the rank order of caffeine>antipyrine>benzoic acid>glyphosate in terms of both the apparent permeability coefficient and the initial slope, defined as the linear rate of substance transferred to the fetal compartment as percent per time, a parameter used to compare the two experimental models. The results from the in vitro studies were in excellent agreement with the ex vivo results (caffeine approximately antipyrine>benzoic acid>glyphosate). However the transfer rate was much slower in the BeWo cells compared to the perfusion system. The advantages and limitations of each model are discussed in order to assist in the preparation, prediction, and performance of future studies of maternal-fetal transfer.