Microplastic Exposure in Neonates Receiving Parenteral Nutrition: A Prospective Cohort Study in the NICU
Phase: NA
Conditions: Microplastics Exposure
Sponsor: Huiyi Li

Exposure to Microplastics in Neonates Receiving Parenteral
Nutrition: A Prospective Cohort Study in Neonatal Intensive Care
Units (Protocol)
2025.1。1

1. Background
Microplastics are defined as plastic particles smaller than 5 millimeters in diameter. This
definition, established by the National Oceanic and Atmospheric Administration (NOAA),
remains
the
most
widely
accepted
standard.
These
particles
exhibit
diverse
morphologies, ranging from fragments and fibers to films, granules, and even foam. Due
to their minuscule size, they are often referred to as "PM2.5 of the ocean." Microplastics
are ubiquitous, present in water bodies, soil, air, and the food chain, with detection
reported in seawater, seafood, drinking water, and even honey. Primary microplastics
(MPs) originate directly from personal care products, synthetic textiles, and industrial
production processes, while secondary microplastics result from the weathering and
mechanical degradation of larger plastic products. Recent advancements in analytical
techniques have led to the detection of microplastics in human blood, lungs, placentas,
and
even
breast
milk,
confirming
their
systemic
distribution
and
potential
for
accumulation in the human body. These findings have sparked significant public and
scientific concern regarding their long-term health impacts, particularly in the most
vulnerable population—neonatal infants.
Newborns, particularly those requiring hospitalization due to preterm birth, low birth
weight, or severe intestinal dysfunction, are exposed to scenarios markedly different
from the general population. In neonatal intensive care units (NICUs), life support and
nutritional supply are highly dependent on plastic medical devices such as intravenous
infusion bags, tubing, infusion pumps, and ventilator circuits. These devices may contain
intentionally added microplastics during production or release secondary microplastics
through physical friction or chemical degradation during use. Of particular significance is
that for critically ill neonates who cannot be fed orally, parenteral nutrition (PN) serves as
their sole source of survival. However, the entire "plastic tubing" system constituting the
parenteral nutrition delivery pathway represents a potential, persistent source of
microplastic exposure. Studies have demonstrated that microplastic particles can be
detected in infusion solutions after passing through plastic equipment[]. This implies that
neonates receiving intravenous nutrition may be subjected to a unique exposure pattern
of "iatrogenic, persistent microplastic infusion."
However, clinical studies on neonatal exposure to AP remain limited. Moreover, most
neonatal biomonitoring studies are based on in vitro experiments and random urine
samples
collected
at
hospital
admission
or
discharge,
without
considering
the
time-dependent nature of exposure. Additionally, there is a lack of research on neonatal
microplastic load, particularly quantitative data in blood. Therefore, this study aims to
assess the current status of neonatal microplastic exposure during NICU hospitalization.
Through a meticulously designed gradient exposure cohort, this study seeks to
systematically evaluate and compare the microplastic load in the blood of neonates
receiving long-term parenteral nutrition for the first time.
2、Materials and Methods
2.1. Study Population and Stratification
This study was a prospective observational study. In 2 02 5,12 neonates were enrolled in
the NICU of the Second Affiliated Hospital of Guangdong Province, Jinan University. All

subjects mothers had no underlying conditions such as heart disease, chronic kidney
disease, mental illness, hypertension, diabetes, gestational hypertension, or gestational
diabetes. Researchers conducted face-to-face interviews to record demographic
information.
All
participants
signed
informed
consent
forms
and
completed
questionnaires. A total of 12 neonatal blood samples, 12 breast milk samples, and 12
bottle milk samples were collected. To accurately assess the dose-response relationship
between the duration of parenteral nutrition and microplastic load, neonatal blood
samples were divided into the following three groups: (1) Long-term exposure group
(n=4): Preterm infants requiring total parenteral nutrition support for>14 days due to
severe feeding difficulties, necrotizing enterocolitis (NEC), short bowel syndrome, or
other serious intestinal diseases. (2) Short-term exposure group (n=4): Preterm infants
receiving total parenteral nutrition support for 3 to 7 days due to early adaptation issues
(e.g., respiratory distress, transient feeding intolerance) and
having successfully
transitioned to total enteral nutrition for at least 48 hours prior to blood sample collection.
This group represented common, transient, routine iatrogenic exposure in NICUs.
Control group (n=4):The cohort consisted of healthy full-term neonates with gestational
age ≥37 weeks. These infants received no intravenous nutritional support or planned fluid
therapy, serving as baseline microplastic levels in the absence of relevant iatrogenic
exposure. The study strictly adhered to the ethical guidelines of the Declaration of
Helsinki, and the protocol was approved by the Medical Ethics Committee of the Second
Affiliated Hospital of Guangdong Province, Jinan University.
2.2 Interview Content
At enrollment, investigators conducted interviews to collect demographic information
from newborns and pregnant women, including education level (high school or below,
bachelors degree, masters degree or above), per capita annual income (<100,000 yuan,
100,000-200,000 yuan,>200,000 yuan), occupation (government official, professional
technician, general clerk, commercial service, other), number of pregnancies (primipara,
multipara), mode of pregnancy (natural delivery, assisted delivery), delivery outcome
(preterm, full-term), delivery method (vaginal delivery, cesarean section), newborn gender
(male, female), and neonatal weight. Details are provided in Table S1.
2.3 Sample Collection
Samples were collected by trained pediatricians and pediatric nurses. After delivery, the
newborns blood was drawn using a non-plastic blood collector and then injected into a
glass anticoagulation tube (KERONG, 3mL, China Chengdu). Breast milk and milk from
bottles were collected by trained nurses or family members and quickly placed into
sample boxes. To avoid contamination, all consumables that came into contact with the
samples during the sampling process were non-plastic products. All samples were
stored in a-80℃environment and strictly anonymized.
2.3 Microplastic Analysis
The sample was transferred to a glass vial and subjected to digestion for a specified
duration to obtain the digestion solution. The sample was then processed through a

membrane and analyzed using a confocal micro-Raman spectrometer. All reagents and
instruments (e.g., test tubes, beakers, pipettes) used during the procedure were
glassware, with no contact with plastic components. When a monochromatic light beam
was incident on the transparent sample, most of the light transmitted while a small
portion was scattered in various directions. When photons undergo inelastic collisions
with sample molecules, the scattered light exhibits energy differences compared to the
incident light, resulting in changes in both frequency and direction. This phenomenon is
termed Raman scattering. The mechanism of Raman scattering involves energy
exchange between photons and molecules, altering the photons energy. Raman shift
spectra are particularly suitable for analyzing molecular structures, especially non-polar
bonds (e.g., C-C bonds) and crystalline materials. Combined with confocal microscopy,
point-by-point scanning generates high-resolution chemical images, enabling precise
localization of microplastic components and their distribution.
2.4 Statistical Analysis
All data analyses were performed using SPSS Statistics 26, with statistical significance
set at a two-tailed test (p <0.05). First, normality testing (Shapiro-Wilk test) and
homogeneity of variance were conducted for measurement data. Variables conforming to
normal distribution were described as mean ± standard deviation, while non-normally
distributed variables (primarily microplastic concentration data) were described as
median (interquartile range, IQR). Categorical data were presented as frequency
(percentage).
For
baseline
characteristic
comparisons
among
the
three
groups,
normal-distributed
continuous
variables
were
analyzed
using
one-way
ANOVA,
non-normally distributed continuous variables were analyzed using the Kruskal-Wallis H
test, and categorical variables were analyzed using Fishers exact test. Some charts were
created using GraphPad Prism 9.0 software, and data were rigorously reviewed.
Statistical analysis of some data was primarily completed using R software (version 4.4.1).
Some plots were generated using ggplot. Correlation coefficients were calculated using
the R function cor.test, and hypothesis testing results were calculated using the R
function wilcox.test.
Survey Form
Characteristics
Categories
Education
High school and below
Bachelor’s degree
Postgraduate and above
Occupation
Governmental official
Profession and technology
General office

Business services
Others
Annual income per capita (CNY)
<100 thousand
100–200 thousand
>200 thousand
Parity
Primipara
Multipara
Mode of conception
Natural conception
Assisted reproduction
Birth outcome
Preterm
Full-term
Mode of delivery
Vaginal delivery
Cesarean delivery
Sex of newborns
Male
Female
Newborn weight (kg)
-