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A girls looks at a tablet computer in a hospitalIn the original phase of the study, TIDES began recruiting pregnant mothers in their first trimester from four study sites: the University of California, San Francisco, University of Minnesota, University of Rochester Medical Center, and Seattle Children’s Hospital/University of Washington. TIDES enrolled almost 800 mothers across sites from 2010 to 2012.

TIDES I aims:

  • Test the hypothesis that prenatal phthalate exposure is associated with reproductive outcomes in male infants
  • Determine population-based norms for anogenital distance (AGD) and other genital markers
  • Develop a reliable method for obtaining these measurements in a clinical setting
  • Test the hypothesis that AGD is a long-lasting marker of phthalate exposure

Participants completed prenatal visits at each trimester, as well as a birth exam and 12-month follow up visit (males only).

TIDES I Results

Results from the first phase of the study indicated that prenatal exposure to phthalates in our diet and homes may affect the reproductive tract development in boys but not in girls. These results were affected by the amount of stress that the mother reported during pregnancy. We also found that women’s attitudes about phthalates and other environmental chemicals vary widely and can influence their consumer choices and the amount of these chemicals to which they are exposed.


TIDES II was funded by the NIH in 2015, which enabled researchers to follow study participants through preschool years. Broadly, the second phase of the study examined the effects of phthalates and stress on early life growth and neurodevelopment.

TIDES II aims:

  • Identify alterations in sexually dimorphic anthropometry and neurodevelopment associated with pre and postnatal phthalate exposure.
  • Determine whether pre and postnatal maternal SLEs and other stress-related measures are associated with the child’s genital and neurodevelopment directly or as modifiers of phthalate effects
  • Estimate associations between AGD and sexually dimorphic anthropometric and neurodevelopmental endpoints

Participants completed study visits at age 4 and age 6. The age 4 visit consisted of questionnaires completed by the TIDES mother and anthropometric measurements and urine collection from the TIDES child. The age 6 visit added pulse wave velocity (a non-invasive test to measure speed blood flow through the arteries), saliva samples and cognitive testing with mom and child.

TIDES II Results

In TIDES II, we observed that exposure to prenatal phthalate mixtures were associated with small changes in autistic like behaviors and increased externalizing behaviors in early childhood. We are currently examining how stressful life events in pregnancy could impact the relationship between phthalate exposures in pregnancy and child health outcomes.


ECHO logoThe Environmental influences on Child Health Outcomes (ECHO) Program is a federal initiative to investigate how exposure to a range of environmental factors in early development – from conception through early childhood – influences the health of children and adolescents. The ECHO program includes over 70 cohorts like TIDES. ECHO expects to include nearly 50,000 children and families from 44 states to address five important child health issues: asthma, neurodevelopment, obesity, airway health and birth outcomes. ECHO will become the largest study to follow children from birth to later childhood ever conducted in the United States. See how participants contribute to ECHO science on this webpage and video summary.

An infographic of people

TIDES is participating in two ECHO Cohort Awardees:

NYU ECHO: The NYU Pediatric Obesity, Metabolism and Kidney Cohort Center (NYU ECHO) endeavors to study prenatal and childhood environmental exposures. The primary objective is to examine mixtures of environmental chemicals at three time points in pregnancy and multiple postnatal periods of vulnerability, in relation to longitudinal trajectories of in-utero and ex-utero growth, as well as longitudinal trajectories of oxidant stress and metabolomics in the prenatal period, infancy, and the school-age years.

ECHO PATHWAYS: The ECHO PATHWAYS study at the University of Washington is designed to investigate how nonchemical (socioeconomic and psychosocial) and common chemical (endocrine disrupting agents and air pollution) stressors during two sensitive time periods, pregnancy and childhood, influence neurodevelopment and airway function. ECHO PATHWAYS combines participants and data from three pre-existing studies: CANDLE (Conditions Affecting Neurocognitive Development and Learning in Early childhood), GAPPS (Global Alliance to Prevent Prematurity and Stillbirth), and TIDES.

Mothers were approached when their child reached age 7 to complete an online questionnaire. Families completed a study visit at age 8-9.  We are currently conducting the age 9-10 visit with TIDES families.


TIDES III was funded by the NIH to follow study participants at ages 12 and 14 and study visits are currently underway. This phase of the study is focused on examining the effects of prenatal and childhood exposure to endocrine-disrupting chemicals on adolescent airway health.


  • Evaluate cross-sectional and longitudinal associations between phthalates and bisphenol from pregnancy through adolescence in relation to measures of airway health from late childhood to adolescence
  • Evaluate associations of (a) prenatal and adolescent serum sex steroid hormones and (b) targeted urinary steroid metabolites in adolescence with male and female airway health at ages 12 and 14
  • Characterize sex differences in associations of EDC exposures in pregnancy and adolescence with serum sex hormones and targeted urinary steroid metabolites in adolescence

Assess serum sex hormones and targeted urinary steroid metabolites as mediators of the relationships between EDC exposures and sex-specific measures of airway health  


  1. Swan SH, Sathyanarayana S, Grady R, Redmon B, Ivicek K, Barrett E, Janssen S. First trimester phthalate exposure and anogenital distance in newborns. Hum Reprod. 2015 Apr;30(4):963-72. PMID: 25697839. PMCID: PMC4359397.
  2. Sathyanarayana S, Grady R, Redmon JB, Ivicek K, Barrett E, Janssen S, Nguyen R, Swan SH, TIDES Study Team. Anogenital distance and penile width measurements in The Infant Development and the Environment Study (TIDES): methods and predictors. J Pediatr Urol. 2015 Apr; 11(2):76.e1-6. PMID: 25824881. PMCID: PMC4456209.
  3. Adibi JJ, Lee MK, Naimi AI, Barrett E, Nguyen R, Sathyanarayana S, Janssen S, Thiet MP, Baskin L, Redmon JB, Swan SH. Human chorionic gonadotropin partially mediates phthalate association with male and female anogenital distance. J Clin Endocrinol Metab. 2015 Sep;100(9):e1216-24. PMID: 26200238. PMCID: PMC4570159.
  4. Alur S, Hongyue W, Hoeger K, Swan SH, Sathyanarayana S, Barrett ES. Urinary phthalate metabolite concentrations in relation to history of infertility and use of assisted reproductive technology. Fertil Steril. 2015 Nov;104(5):1227-35. PMID: 26275821. PMCID: PMC4630141.
  5. Barrett E, Sathyanarayana S, Redmon B, Brantley E, Fiore H, Janssen S, Nguyen R, Kobrosly R, Swan SH, and the TIDES Study Team. Prenatal stress as a modifier of associations between phthalate exposure and reproductive development: results from a multicenter pregnancy cohort study. Paediatr Perinat Epidemiol. 2016 Mar;30(2): 105-14. PMID: 26576028. PMCID: PMC4749428.
  6. Martino-Andrade AJ, Liu F, Sathyanarayana S, Barrett ES, Redmon JB, Nguyen RH, Levine H, Swan SH; TIDES Study Team. Timing of prenatal phthalate exposure in relation to genital endpoints in male newborns. Andrology. 2016 Jul;4(4):585-93. Epub 2016 Apr 7. PMID: 27062102 
  7. Sathyanarayana S, Barrett E, Nguyen R, Redmon B, Haaland W, Swan SH. First trimester phthalate exposure and infant birth weight in the Infant Development and Environment Study. Int J Environ Res Public Health. 2016 Sep 23;13(10). PMID: 27669283. PMCID: PMC5086684.
  8. Sathyanarayana S, Grady R, Barrett E, Redmon B, Nguyen R, Bush N, Swan SH, and the TIDES Study Team. First trimester phthalate exposure and newborn male genital anomalies. Environ Res. 2016 Nov; 151:777-82. PMID: 27567446.
  9. Sathyanarayana S, Butts S, Wang C, Barrett E, Nguyen R, Schwartz SM, Haaland W, Swan SH. Early Prenatal Phthalate Exposure, Sex Steroid Hormones, and Birth Outcomes. J Clin Endocrinol Metab. 2017 Jun 1; 102(6):1870-1878. PMID: 28324030. PMCID: PMC5470772.
  10. Barrett ES, Sathyanarayana S, Bowe O, Thurston SW, Redmon JB, Nguyen RHN, Swan SH. First-Trimester Urinary Bisphenol A Concentration in Relation to Anogenital Distance, an Androgen-Sensitive Measure of Reproductive Development, in Infant Girls. Environ Health Perspect. 2017 Jul 11; 125(7):077008. PMID: 28728138. PMCID: PMC5744699.
  11. Barrett E, Sathyanarayana S, Redmon B, Brantley E, Fiore H, Janssen S, Nguyen R, Kobrosly R, Swan SH, and the TIDES Study Team. Anogenital distance in newborn daughters of women with polycystic ovary syndrome indicates fetal testosterone exposure. Dev Orig Health Dis. 2018 Jun;9(3):307-314. Epub 2018 Jan 9. PMID: 29310733. PMCID: PMC5997496.
  12. Bornehag CG, Lindh C, Reichenberg A, Wikström S, Hallerback MU, Evans SF, Sathyanarayana S, Barrett ES, Nguyen RHN, Bush NR, Swan SH. Association of prenatal phthalate exposure with language development in early childhood. JAMA Pediatr. 2018 Dec 1;172(12):1169-1176. PMID: 30383084. PMCID: PMC6583016.
  13. Rosen EM, van ‘t Erve TJ, Boss J, Sathyanarayana S, Barrett ES, Nguyen RHN, Bush NR, Milne GL, McElrath TF, Swan SH, Ferguson KK. Urinary oxidative stress biomarkers and accelerated time to spontaneous delivery. Free Radic Biol Med. 2019 Jan;130:419-425. PMID: 30445128. PMCID: PMC6331226.
  14. Shaffer RM,  Ferguson KK, Sheppard L, James-Todd T, Butts S, Chandrasekaran S, Swan SH, Barrett ES, Nguyen R, Bush N, McElrath TF, Sathyanarayana S, TIDES Study Team. Maternal urinary phthalate metabolites in relation to gestational diabetes and glucose intolerance during pregnancy. Environ Int. 2019 Feb:588-596. PMID: 30622083. PMCID: PMC6347428.
  15. van 't Erve TJ; Rosen EM, Barrett ES, Nguyen RHN, Sathyanarayana S, Milne GL, Calafat AM, Swan SH, Ferguson KK. Phthalates and phthalate alternatives have diverse associations with oxidative stress and inflammation in pregnant women. Environ Sci Technol. 2019 Mar 19;53(6): 3258-3267. PMID: 30793895. PMCID: PMC6487641.
  16. Barrett ES, Mbowe O, Thurston SW, Butts S, Wang C, Nguyen R, Bush N, Redmon JB, Sheshu S, Swan SH, Sathyanarayana, S. Predictors of steroid hormone concentrations in early pregnancy: results from a multi-center cohort. Matern Child Health J. 2019 Mar;23(2):397-407. PMID: 30659461. PMCID: PMC6397082.
  17. Ferguson KK, Rosen EM, Barrett ES, Nguyen RHN, Bush N, McElrath TF, Swan SH, Sathyanarayana S. Joint impact of phthalate exposure and stressful life events in pregnancy on preterm birth. Environ Int. 2019 Dec;133(Pt B): 105254. PMID: 31675562.
  18. Day DB, Collett BR, Barrett ES, Bush NR, Swan SH, Wang C, Sathyanarayana S, TIDES Study Team. Prenatal sex hormones and behavioral outcomes in children. Psychoneuroendocrinology. 2020 Mar;113:104547. doi: 10.1016/j.psyneuen.2019.104547. Epub 2019 Dec 24. PMID: 31901731.
  19. Lyden GR, Barrett ES, Sathyanarayana S, Bush NR, Swan SH, Nguyen RHN. Pregnancy intention and phthalate metabolites among pregnant women in The Infant Development and Environment Study cohort. Paediatr Perinat Epidemiol. 2020 Nov;34(6):736-743. doi: 10.1111/ppe.12674. Epub 2020 Apr 6. PMID: 32249967; PMCID: PMC7541656..
  20. Evans SF, Raymond S, Sethuram S, Barrett ES, Bush NR, Nguyen R, Sathyanarayana S, Swan SH. Associations between prenatal phthalate exposure and sex-typed play behavior in preschool age boys and girls. Environ Res. 2021 Jan;192:110264. doi: 10.1016/j.envres.2020.110264. Epub 2020 Sep 28. PMID: 32997969.
  21. Day DB, Collett BR, Barrett ES, Bush NR, Swan SH, Nguyen RHN, Szpiro AA, Sathyanarayana S. Phthalate mixtures in pregnancy, autistic traits, and adverse childhood behavioral outcomes. Environ Int. 2021 Feb;147:106330. doi: 10.1016/j.envint.2020.106330. Epub 2021 Jan 5. PMID: 33418196.
  22. Barrett E, Thurston SW, Harrington D, Bush NR, Sathyanarayana S, Nguyen R, Zavez A, Wang C, Swan S. Digit ratio, a proposed marker of the prenatal hormone environment, is not associated with prenatal sex steroids, anogenital distance, or gender-typed play behavior in preschool age children. J Dev Orig Health Dis. 2021 Dec;12(6):923-932. doi: 10.1017/S2040174420001270. Epub 2020 Dec 18. PMID: 33336644; PMCID: PMC8211903.
  23. Lesseur C, Pirrotte P, Pathak KV, Manservisi F, Mandrioli D, Belpoggi F, Panzacchi S, Li Q, Barrett ES, Nguyen RHN, Sathyanarayana S, Swan SH, Chen J. Maternal urinary levels of glyphosate during pregnancy and anogenital distance in newborns in a US multicenter pregnancy cohort. Environ Pollut. 2021 Jul 1;280:117002. doi: 10.1016/j.envpol.2021.117002. Epub 2021 Mar 22. PMID: 33812205.
  24. Arogbokun O, Rosen E, Keil AP, Milne GL, Barrett E, Nguyen R, Bush NR, Swan SH, Sathyanarayana S, Ferguson KK. Maternal Oxidative Stress Biomarkers in Pregnancy and Child Growth from Birth to Age 6. J Clin Endocrinol Metab. 2021 Apr 23;106(5):1427-1436. doi: 10.1210/clinem/dgab018. PMID: 33524128; PMCID: PMC8171170.
  25. Bedell SM, Lyden GR, Sathyanarayana S, Barrett ES, Ferguson KK, Santilli A, Bush NR, Swan SH, McElrath TF, Nguyen RHN. First- and Third-Trimester Urinary Phthalate Metabolites in the Development of Hypertensive Diseases of Pregnancy. Int J Environ Res Public Health. 2021 Oct 11;18(20):10627. doi: 10.3390/ijerph182010627. PMID: 34682373; PMCID: PMC8536149.
  26. Lesseur C, Pathak KV, Pirrotte P, Martinez MN, Ferguson KK, Barrett ES, Nguyen RHN, Sathyanarayana S, Mandrioli D, Swan SH, Chen J. Urinary glyphosate concentration in pregnant women in relation to length of gestation. Environ Res. 2022 Jan;203:111811. doi: 10.1016/j.envres.2021.111811. Epub 2021 Jul 30. PMID: 34339697; PMCID: PMC8616796.

A complete list of publications can be found here.