Researchers followed 87 pregnant women and their babies to see how the mother’s health during pregnancy affected how fast the baby grew in the first year of life. They measured the mother’s weight, diet quality, and exercise habits during pregnancy, then tracked the baby’s growth at birth, 6 weeks, 6 months, and 12 months. The study found that mothers who were healthier during pregnancy—eating better quality food and exercising more—tended to have babies who grew at a healthy pace. Interestingly, maternal weight gain during pregnancy was also linked to faster infant growth. These findings suggest that taking care of yourself during pregnancy may help set your baby up for healthy growth.
The Quick Take
- What they studied: Whether a pregnant woman’s weight, diet quality, and exercise habits affect how quickly her baby grows during the first year of life.
- Who participated: 87 mother-baby pairs from Australia who were part of a larger study about pregnancy and health. Researchers collected information about the mothers during pregnancy and measured the babies’ growth multiple times in their first year.
- Key finding: Mothers who ate higher quality diets and exercised regularly during pregnancy had babies who grew at healthier rates during the first year. Additionally, mothers who gained more weight during pregnancy tended to have babies with faster growth patterns.
- What it means for you: If you’re pregnant or planning to become pregnant, maintaining a healthy diet and staying physically active may help support your baby’s healthy growth. However, this is one small study, so talk with your doctor about what’s right for your individual situation.
The Research Details
This study followed 87 pregnant women and their babies over time, collecting information at different stages. The researchers measured the mothers’ weight at three different points during pregnancy (each trimester). They also asked mothers about their eating habits and exercise using standard questionnaires designed to measure diet quality and physical activity levels. For the babies, researchers measured weight and length at birth, 6 weeks, 6 months, and 12 months of age.
The researchers then used statistical analysis to look for connections between what the mothers did during pregnancy and how their babies grew. They adjusted their analysis to account for other factors that might affect baby growth, like the baby’s sex and birth weight, to make sure they were seeing the real relationship between maternal health and infant growth.
This type of study is valuable because it follows people over time and collects detailed information about their behaviors and health, allowing researchers to spot patterns that might be important for health.
Understanding how a mother’s health during pregnancy affects her baby’s growth is important because growth patterns in infancy can have long-term effects on a child’s health. By identifying which maternal behaviors are connected to healthy infant growth, doctors and health professionals can give better advice to pregnant women about diet and exercise.
This study has some strengths: it measured multiple aspects of maternal health (weight, diet, and exercise), tracked babies over a full year, and used established questionnaires to measure diet and activity. However, the sample size of 87 mother-baby pairs is relatively small, which means the findings need to be confirmed in larger studies. The study is observational, meaning researchers watched what happened naturally rather than randomly assigning women to different diets or exercise programs, so we can’t be completely certain that maternal behaviors directly caused the growth differences.
What the Results Show
Mothers who had higher quality diets in early pregnancy had babies who showed healthier growth patterns throughout the entire first year of life. This relationship was measured using growth scores that account for the baby’s age, and the connection was statistically significant, meaning it’s unlikely to have happened by chance.
Maternal weight—both at the beginning of pregnancy and at the end—was linked to faster infant growth in the first six months. Additionally, the amount of weight mothers gained during pregnancy was associated with changes in their babies’ growth measurements.
Mothers who exercised more during pregnancy had babies who showed increased growth measurements, particularly in length (how tall the baby was). This relationship held true whether the exercise was measured early, middle, or late in pregnancy, suggesting that staying active throughout pregnancy may be beneficial.
Greater maternal body fat was associated with faster infant growth between 6 weeks and 6 months of age.
The study looked at a specific type of growth measurement called ‘conditional weight gain,’ which accounts for a baby’s previous growth and shows how much faster or slower a baby is growing compared to their own growth pattern. This measurement was affected by maternal diet quality, exercise, and body composition, suggesting these factors influence not just overall size but the rate of growth itself.
Previous research has shown that maternal nutrition and weight during pregnancy matter for baby health, but this study adds new information by tracking growth throughout the entire first year and looking at multiple maternal factors together. The findings align with the general understanding that maternal health during pregnancy has lasting effects on infants, though the specific connections between maternal exercise and infant growth patterns are less well-studied and warrant further investigation.
The study included only 87 mother-baby pairs, which is a relatively small number. This means the findings might not apply to all populations, especially those with different ethnic backgrounds or living in different countries. The study only included Australian families, so results may differ elsewhere. Additionally, because this is an observational study, we cannot say for certain that maternal behaviors directly caused the growth differences—other unmeasured factors could be involved. The researchers did their best to account for other important factors, but some might have been missed. Finally, the study is from 2026, so it’s very recent and the findings need to be confirmed by other researchers before we can be completely confident in the results.
The Bottom Line
Pregnant women should aim to eat a high-quality diet rich in whole foods and stay physically active during pregnancy, as this research suggests these behaviors may support healthy infant growth (moderate confidence level). Weight gain during pregnancy should be discussed with your healthcare provider, as appropriate weight gain varies by individual circumstances. These recommendations should complement, not replace, guidance from your obstetrician or midwife.
Pregnant women and those planning pregnancy should pay attention to these findings. Healthcare providers counseling pregnant women about nutrition and exercise may find this research useful. However, women with specific health conditions, high-risk pregnancies, or those carrying multiples should follow their doctor’s individualized advice rather than general recommendations.
If these findings apply to you, the effects on infant growth would be visible starting from birth and continuing through the first year of life. You wouldn’t see immediate changes, but rather gradual differences in growth patterns over months.
Want to Apply This Research?
- Track weekly diet quality using a simple scoring system (e.g., servings of vegetables, whole grains, and lean proteins) and weekly minutes of moderate physical activity. Compare these to infant growth measurements taken at 6-week intervals to identify personal patterns.
- Set a specific goal such as ’eat 5 servings of vegetables daily’ and ’exercise 150 minutes per week’ during pregnancy, logging these activities in the app to maintain accountability and see correlations with baby growth milestones.
- Create a dashboard showing maternal diet quality and activity levels alongside infant growth curves (weight and length percentiles) to visualize the relationship between maternal behaviors and baby growth over the first 12 months.
This research suggests associations between maternal health behaviors and infant growth but does not prove direct causation. Individual pregnancy circumstances vary greatly, and what’s appropriate for one person may not be for another. All pregnant women should follow personalized medical advice from their obstetrician, midwife, or healthcare provider rather than making changes based solely on this research. This study is preliminary and requires confirmation through larger research before being considered definitive guidance. If you are pregnant or planning pregnancy, consult your healthcare provider before making significant changes to your diet or exercise routine.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.