Related Experiment Video
Updated: Aug 7, 2026

Modifying Levels of Maternal Dietary Folic Acid or Choline to Study the Impact of Deficiencies on Offspring Health Outcomes
Published on: June 28, 2024
Interaction of maternal protein and carbon monoxide on pup mortality in mice: implications for global infant
1Stillman College, Tuscaloosa, Alabama 35403, USA. jsingh@stillman.edu
Insights
Maternal protein deficiency and carbon monoxide (CO) exposure significantly increase infant mortality. These factors interact, highlighting risks from pollution and poor nutrition during pregnancy.
Area of Science:
- Environmental Health
- Nutritional Science
- Developmental Biology
Background:
- Protein deficiency in pregnant mothers is prevalent in developing nations.
- Carbon monoxide (CO) pollution poses a significant public health risk globally.
- Improving child health necessitates addressing maternal nutrition and environmental exposures.
Purpose of the Study:
- To investigate the combined effects of dietary protein restriction and carbon monoxide (CO) exposure on pregnancy outcomes in a mouse model.
- To determine the impact of varying protein levels and CO concentrations on pup mortality and weight.
Main Methods:
- A two-way factorial design exposed pregnant mice to diets with 4%, 8%, 16%, or 27% protein.
- Dams were exposed to 0, 65, or 125 ppm of CO for 6 hours daily during early gestation.
- Pup mortality and weight were recorded post-delivery.
Main Results:
- Pup weight was reduced by higher CO levels and lower protein diets.
- Pup mortality increased significantly with CO exposure and was inversely related to protein levels.
- All pups died at 4% protein, and most died at 8% protein across all CO concentrations.
Conclusions:
- Protein deficiency and CO exposure synergistically increase pup mortality during gestation.
- These factors may contribute to high infant mortality rates in developing countries and vulnerable populations.
- Indoor air pollution from combustion sources is a critical factor impacting global child health.
Background:
The United States Surgeon General declared 2005 as the "Year of Healthy Child." To improve the health of all children, we need to start before pregnancy, with their mothers. Unfortunately, protein deficiency in the diets of poor pregnant mothers in developing countries is widespread. Carbon monoxide (CO) pollution is serious public health problem in developed and developing countries.
Methods:
A two-way factorial experimental design was used. Mice were maintained on 27%, 16%, 8%, or 4% protein diets. Dams were exposed to 0 ppm (control), 65 ppm, or 125 ppm CO in air, in environmental chambers for 6 hr/day during the first 2 weeks of pregnancy. Controls were also subjected to environmental chamber conditions. Food and water were available at all times. Animals were allowed to deliver, and data on pup mortality was recorded.
Results:
Litter size was not affected by CO exposure, but was directly related to the dietary protein levels. Pup weight was inversely related to the CO exposure level, and directly related to the dietary protein levels. Pup mortality on date of birth was increased by CO exposure and was inversely related to the dietary protein levels. Pup mortality at 1 week of age was increased by CO exposure and 55% of all pups died in 125 ppm CO exposed group. Pup mortality at 1 week of age was inversely related to dietary protein levels. All pups in the 4% dietary protein and in all concentrations of CO died. All pups in the 8% protein group and in all CO concentrations died except in 125 ppm CO group. Pup mortality in the 16% dietary protein group ranged from 14.8% in 0 ppm to 36.8% in 65 ppm CO groups. Pup mortality in the 27% dietary protein group ranged from 14.3% in the 0 ppm to 41.1% in the 125 ppm CO groups.
Conclusions:
DATA suggest that protein deficiency and CO exposure enhance pup mortality. The protein and CO also interact to increase pup mortality in 16% and 27% protein groups. Carbon monoxide exposure, along with protein deficiency during gestation, may be contributing factors for high rates of infant mortality in developing countries. The results of the study also suggest that un-vented combustion for heating and cooking, ambient pollution, and biomass smoke may have a major impact on the health of children worldwide; and may explain the causes of high infant mortality in poor countries and some sections of the United States population.

