From womb to world: The role of micronutrients in shaping infant development

12th June 2024 - UC Science

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Pregnancy is often a time of joy for many, while for some it can be a time associated with challenges such as maternal depression.

Numerous studies have documented the impact of depression and other mental health issues during the prenatal period on infant development. Prenatal depression impacts approximately 20% of pregnant people (Svardal et al., 2022; Yin et al., 2021), and not only does this make their experience of pregnancy even more challenging, but it can have long lasting impacts on the infant and wider whānau (Jahan et al., 2021).

Antenatal Depression, Infant Outcomes and Current Treatment Considerations

If an infant is exposed to depression during the prenatal period, it may put them at greater risk of poorer birth outcomes (including increased risk of pre-term birth and low birth weight) (Jahan et al., 2021)

As a result, there has been increasing interest in the continued development of a strong evidence base for treatments for maternal depression in pregnancy, including investigation into the effectiveness of psychiatric medications, psychological interventions, and most recently, nutritional interventions.

The NUTRIMUM trial and Infant Development Study

A recent study conducted within Te Puna Toiora (Mental Health and Nutrition Research Lab) based at the University of Canterbury explored the impact of a high-dose, broad-spectrum, vitamin and mineral supplement (collectively referred to as micronutrients) given to pregnant women as a treatment for antenatal depression (the NUTRIMUM trial) (Bradley et al., 2020; Bradley et al., 2024), and whether it may impact infant development in the first year of life (Infant Development Study) (Campbell et al., 2024; Campbell et al., 2024).

The results of the impact of the micronutrients on depression in pregnancy have been discussed in a previous blog.

The studies focused on the infant were focused on better understanding the impact of the micronutrients on infant temperament and neurobehavioural development (any behaviour linked to the brain and central nervous system) and assessing infant capacity across several domains including early signs of regulation, social development and ability to interact with the external environment, the stability of the central nervous system in the face of increasing stress, and motor development including muscle tone and motor maturity.

Infants whose mothers were enrolled in the NUTRIMUM trial, and were therefore exposed to micronutrients during pregnancy, were followed for 12 months alongside another group of infants from the general population of Aotearoa New Zealand who were not exposed to the micronutrients.

This second group of infants contained a smaller sub-group who were exposed to antidepressant medication for the treatment of antenatal depression. Neurobehavioural development of each infant was then assessed within the first 4 weeks of life, and temperament was assessed at 2 months,  4 months, 6 months, and 12 months postnatally.

What did the study find?

A portion of the results of this study were recently published in Early Human Development. The study found that infants exposed to micronutrients during pregnancy were significantly better at attending to and blocking out external stimuli whilst in a sleep state, showed fewer signs of stress to the central nervous system, and had better motor maturity and muscle tone compared to infants not exposed to micronutrients.

Further, infants exposed to the micronutrients also displayed greater ability to attend to and interact with their external environment, were better at regulating their state, and had fewer abnormal muscle reflexes than infants exposed to antidepressant medication in pregnancy.

The results of a second publication explored the effect of the nutrient exposure on infant temperament and identified no adverse effects on temperament, with micronutrient infants displaying similar temperamental profiles to non-nutrient exposed infants, even suggesting the nutrients may have a potential positive effect on negative affectivity and regulatory capacity.

What does this mean?

Nutritional interventions in the treatment of mental health conditions is an emerging, and important field. The results of this study confirm that internal and external environmental influences in the antenatal period have the ability to affect later infant outcomes, and in this case, in utero exposure to micronutrients had a positive impact on infant neurobehaviour, and may have even mitigated some of the risks of poor infant outcomes related to maternal antenatal depression.

Given the known negative effects of untreated maternal depression during pregnancy, and potential side effects of existing treatment options, it is important to continue exploration into alternative options for pregnant people.

The antenatal environment sets the foundation for a child’s future, and further investigation into the benefits of micronutrient supplementation on both mother and baby is warranted.

Overall, the results of this study provide preliminary evidence for the use of broad-spectrum micronutrients as a treatment for antenatal depression, appears to promote healthy infant neurobehaviour, and there was no evidence of the micronutrients increasing harm, potentially even setting these infants up for a better start in life.