ECHO Cohort Researchers Find Association Between Some Prenatal Chemical Exposures and Postpartum Depression

Authors: Melanie Jacobson, et al.

Who sponsored this study?

The Environmental influences on Child Health Outcomes (ECHO) Program, Office of the Director, National Institutes of Health supported this research.

Why was this study needed?

Postpartum depression affects up to 20% of new mothers, making it the most common pregnancy complication to occur after delivery. Postpartum depression can impact a mother’s daily functioning, quality of life, and long-term health. Furthermore, it is associated with poor mother-child attachment, which can impact child health and development.

Factors like genetics and stress can make some people more likely to experience postpartum depression, but researchers are still trying to understand how synthetic chemicals might also play a role. Chemicals such as phenols, phthalates, and parabens can be found in plastics and personal care products. While these chemicals are nonpersistent, meaning that they don’t linger in the environment, their presence is widespread due to frequent exposure through diet, absorption through skin, and inhalation. The investigators in this study wanted to examine the extent to which exposure to these chemicals might be associated with postpartum depression symptoms.

What were the study results?

Prenatal phthalate concentrations were associated with increased odds of slightly higher postpartum depression scores, and the condition was observed to be more likely in people who were Hispanic, had lower education levels, and had prenatal depression.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

Of the many synthetic chemicals investigated, only prenatal phthalate concentrations were associated with increased odds of postpartum depression. This suggests that finding ways to reduce prenatal exposure to phthalates might reduce the frequency of postpartum depression.

Who was involved?

Researchers used data from 2,174 pregnant individuals across five study sites. This information included data on urinary chemical concentrations from at least one point during the pregnancy and a self-reported postnatal depression assessment between two weeks and 12 months after delivery.

What happened during the study?

Researchers measured the concentrations of nonpersistent chemicals in urine samples. Researchers also collected, between two weeks and 12 months after delivery, data using self-reported postnatal depression assessments completed by the same individuals. Screening instruments indicated the presence or absence of postnatal depressive symptoms. Data was then harmonized to the Patient-Reported Measurement Information System (PROMIS) Depression scale.

What happens next?

While this is believed to be the largest study to-date examining the effects of environmental chemicals on postpartum depression, future studies are needed to replicate this research with larger sample sizes in diverse populations.

Where can I learn more?

Access the full journal article, titled “Prenatal exposure to nonpersistent environmental chemicals and postpartum depression,” in JAMA Psychiatry.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published September 20, 2023

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ECHO Cohort Researchers Find Association Between Some Prenatal Chemical Exposures and Postpartum Depression.

Exposure to Certain Phthalates During Pregnancy May Affect Brain Development in Infant Girls

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Exposure to Certain Phthalates During Pregnancy May Affect Brain Development in Infant Girls

Authors: Leny Matthew, Craig Newschaffer, et al.

Who sponsored this study?

The Environmental influences on Child Health Outcomes (ECHO) Program, Office of the Director, National Institutes of Health supported this research.

What were the study results?

In this study, researchers found that certain phthalates measured in the infant’s meconium, or first stool, were associated with lower scores on a common test that measures motor, visual, and language skills in girls under age 5.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

This study suggests that prenatal exposure to certain types of phthalates may worsen early childhood learning outcomes for girls but have a neutral or slightly positive effect on boys. By studying meconium, instead of maternal urine, the researchers may be able to capture a longer timeframe of potential pre-natal exposure.

Why was the study needed?

Phthalates are widely used in personal care products, cosmetics, plastics, and other household items. These chemicals can cause the body to make substances that are thought to reduce a mother’s level of thyroid hormones, which are critical for fetal brain development. Phthalates are also associated with a reduction in the hormones necessary for sex-specific fetal brain development. Therefore, it is important to test the levels of prenatal phthalate exposure and the potential effects on developing fetuses.

Who was involved?

The study involved 956 mother and child pairs from two ECHO research sites—the Safe Passage study (SPS) and the Early Autism Risk Longitudinal Investigation (EARLI). Researchers focused on children who were higher risk for brain and nervous system disorders based on a family history of Autism or exposure to alcohol during pregnancy.

What happened during the study?

ECHO researchers measured phthalate levels in meconium from children who had a higher risk for developing brain and nervous system disorders. When the children were 12 months old, researchers tested their motor, visual, and language skills. Researchers used meconium samples rather than the mother’s urine to capture longer-term fetal exposure to phthalates.

What happens next?

Future prenatal phthalate exposure studies using meconium samples from newborn infants could investigate the differing effects of phthalate exposure on male versus female infants in order to better understand the reasons why these differences may occur.

Where can I learn more?

Access the full journal article, titled “The associations between prenatal phthalate exposure measured in child meconium and cognitive functioning of 12-month-old children in two cohorts at elevated risk for adverse neurodevelopment,” in Environmental Research.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published November 2022

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Exposure to Certain Phthalates During Pregnancy May Affect Brain Development in Infant Girls

ECHO Study Links Phthalate Exposure During Pregnancy With Genetic Changes in the Placenta

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ECHO Study Links Phthalate Exposure During Pregnancy With Genetic Changes in the Placenta

Authors: Alison Paquette, Sheela Sathyanarayana, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, Office of The Director, National Institutes of Health.

What were the study results?

Researchers found that several phthalates were associated with changes in the expression of 38 genes within the placenta. Some of these changes in gene expression were only significant in male or female infants. This shows that phthalates may change how the placenta works in different ways for the two sexes. The team also studied which biological pathways were connected to these changes in gene expression. They found 27 specific pathways that may have been affected by phthalate exposure. These pathways involved important building blocks for the developing infant.

What was the study's impact?

Exposure to phthalate chemicals is related to changes in gene expression in placentas. This is important because these changes in gene expression may affect the growing baby.

Why was this study needed?

There is a lot we still don’t know about how phthalates affect the placenta. Phthalates are a group of chemicals used in plastics and household products. The placenta is an organ in pregnant women that provides their growing baby with oxygen and nutrients. It also helps mothers and babies share information. Exposure to phthalates during pregnancy may harm the placenta and affect how the baby develops. Looking at changes in how genes are expressed when exposed to phthalates during pregnancy can help researchers measure the effect on how the placenta works. Genes are expressed when DNA is converted into proteins, which perform a variety of important functions and play critical roles in development.

Who was involved?

The study involved pregnant women from Memphis, Tennessee who enrolled in the CANDLE study during their pregnancy. Researchers collected urine and placentas from mothers just after their babies were born. These participants were between 16-40 years old, mostly Black, and had relatively healthy pregnancies.

What happened during the study?

Researchers measured the amount of 16 phthalates in urine collected from the participants during the 2nd and 3rd trimester of pregnancy.

Researchers collected the placenta from the mother after having the baby and measured the expression of each gene in the placenta. For each gene, the researchers tried to figure out if higher phthalate concentrations were related to more or less gene expression in the placenta. This information was used to understand how phthalates may have affected how the placenta worked.

What happens next?

This research team will study how changes in the placenta are related to pregnancy complications like preterm birth within this same group of pregnant women. They will also use new tools and technologies to study how phthalates may cause these changes in gene expression.

It is also important to look at the effect of phthalates on other groups of women and see how these changes in placental function impact infant and childhood health.

Where can I learn more?

Read more information about how people are exposed to phthalates and how to decrease exposures.

Access the full journal article, titled “A Comprehensive Assessment of Associations between Prenatal Phthalate Exposure and The Placental Transcriptomic Landscape” in Environmental Health Perspectives.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published September 3, 2021

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ECHO Study Links Phthalate Exposure During Pregnancy With Genetic Changes in the Placenta