Elicit: Effects of Microplastics on Pregnancy

Effects of Microplastics on Pregnancy

What are the effects of microplastic exposure during pregnancy?

Research shows that maternal exposure to microplastics during pregnancy disrupts maternal physiology, compromises placental integrity, and impairs fetal growth and development.

Abstract

Microplastic exposure during pregnancy shows measurable impacts on maternal physiology, placental integrity, and fetal development. In rodent studies, exposure to primarily polystyrene and polyethylene particles via drinking water, oral gavage, or inhalation has been associated with the following outcomes:

Maternal changes such as altered cardiovascular parameters (e.g., increased heart and spleen weight, vascular dysfunction), reproductive delays (e.g., disturbed estrous cyclicity and diminished fertility), metabolic disruptions, and shifts in liver weight or function.
Placental findings that include accumulation of microplastics (with one report noting a mean concentration of 6.91 mg/g in 100% of placentae) and altered vascular flow—up to a 43% increase in umbilical artery flow in one study.
Fetal effects marked by growth restriction—for example, a 12% reduction in fetal weight at 106 ng/L exposure—and neurodevelopmental disruptions, including hippocampal ferroptosis, reduced myelin formation, and altered neurotransmitter levels.

Biochemical assessments reveal increased oxidative stress, inflammation, and modulated gene expression linked to lipid metabolism and angiogenesis. In several experiments, higher doses (for instance, exposures equivalent to levels producing dose-dependent effects in mice) correspond with more pronounced adverse outcomes. These findings indicate that microplastic exposure during gestation may perturb maternal, placental, and fetal systems in measurable ways.

Methods

We analyzed 40 sources from an initial pool of 499, using 5 screening criteria. Each paper was reviewed for 5 key aspects that mattered most to the research question.

Papers identified with Elicit search

n = 499

Papers screened using:

Study Population
Exposure Assessment
Outcome Measures
Study Design
Exposure Quantification

Results: 499 papers screened out 459 papers, included 40 for extraction.

Characteristics of Included Studies

Study	Study Design	Microplastic Type/Size	Exposure Route	Species/Model	Full text retrieved
Aghaei et al., 2022	Animal experimental	Polystyrene, 5 μm and 50 nm	Drinking water	Mice	No
Amereh et al., 2022	Observational cross-sectional	Polyethylene, Polystyrene, <5 mm	Not applicable (detected in placenta)	Human	No
Barrozo et al., 2024	Observational	Polyethylene, < 20 μm	Not applicable (detected in placenta)	Human	No
Cary et al., 2024	Animal experimental	Polystyrene nanoplastic	Intratracheal instillation	Rats	No
Chen et al., 2022	Animal experimental	Polystyrene, 100 nm	Drinking water	Mice	No

The extracted data indicates that many of the included studies were animal experiments, often using mice models, and frequently examining polystyrene nano- and microplastics.

Effects of Microplastic Exposure

Maternal Effects

Study	Effect Category	Observed Changes	Exposure Level	Significance
Aghaei et al., 2022	-	No mention found	102, 104, or 106 ng/L	No mention found
Dou et al., 2024	Reproductive	Delayed puberty, disturbed estrous cyclicity, diminished fertility	No mention found	No mention found
Fournier et al., 2020	Organ deposition	Nanopolystyrene particles in lung, heart, spleen	2.64 × 10^14 particles	No mention found

Placental and Fetal Effects

Study	System Affected	Observed Changes	Exposure Level	Key Findings
Aghaei et al., 2022	Fetal growth	12% decrease in fetal weight	106 ng/L	Significant fetal growth restriction at highest exposure
Amereh et al., 2022	Fetal growth, Development	Reduced birth weight, length, head circumference	Not applicable	Inverse associations between microplastic exposure and birth outcomes
Barrozo et al., 2024	Placenta	Microplastic accumulation	Mean 6.91 mg/g	Microplastics detected in 100% of placentae

Biochemical and Molecular Changes

Oxidative Stress: Increased malondialdehyde generation and altered superoxide dismutase and catalase activities in offspring tissues.
Inflammation: Increased levels of inflammatory markers such as monocyte chemoattractant protein-1 and tumor necrosis factor-alpha in neonatal livers.
Gene Expression Changes: Dysregulation of genes involved in angiogenesis and visual system development in offspring.

Dose-Dependent Relationships

Several studies reported dose-dependent effects of microplastic exposure during pregnancy:

Fetal Growth: Chen et al. (2024a) observed dose-responsive harmful effects on fetal development.
Placental Effects: Zhang et al. (2022) found maternal exposure to polystyrene nanoplastics caused dose-dependent structural damage to the placenta.