By Jessica Heaton, MSc, postgraduate student in clinical psychology.
Pregnancy can be an exciting journey for many, but for others, it comes with unexpected challenges, such as maternal depression. Depression during pregnancy, or antenatal depression, affects approximately 20% of pregnant individuals. It doesn’t just make pregnancy harder—it can have long-term effects on infants and the wider whānau. Research consistently shows that untreated depression during pregnancy increases the risk of complications like preterm birth, low birth weight, and even infant health interventions after delivery.
For more information on antenatal depression please read our previous blog post.
Current Treatments for Antenatal Depression: Are They Enough?
Psychological therapy is often the first-line treatment for antenatal depression, but access can be limited by cost, time, and availability. Antidepressants, while effective for managing symptoms, carry concerns about potential impacts on foetal development, including low birth weight, preterm birth, and higher admission rates to specialized care. Although a recent umbrella meta-analysis reported adverse health outcomes associated with psychotropic medications are suggestive at best, there is no evidence that these medications are reducing the risks associated with untreated depression down to levels observed in pregnancies of nondepressed individuals. Further, despite these assurances on the absence of serious adverse effects and overall low estimation of the clinical significance of effects that have been observed, pregnant women are often reluctant to use psychiatric medications. As such, other treatment options are needed.
These limitations have sparked interest in nutritional interventions, which are gaining recognition for their role in supporting mental health during pregnancy. This is where the NUTRIMUM trial steps in.
What Did this phase of the NUTRIMUM Trial Explore?
The NUTRIMUM trial, conducted at Te Puna Toiora (Mental Health and Nutrition Research Lab) within the University of Canterbury, examined whether broad-spectrum micronutrients—a combination of vitamins and minerals—could offer a safer, effective alternative to antidepressants for treating symptoms of antenatal depression. The first phase was a randomised trial of the micronutrients versus an active placebo. Those results were described here. The second phase consisted of an observational study, recruiting other pregnant women to help contextualise the effect of the nutrients on birth outcomes.
The observational follow up study included three groups:
- MN Group (Micronutrients): Mothers taking micronutrients for at least eight weeks to treat symptoms of antenatal depression.
- MED Group (Medications): Mothers using antidepressants during pregnancy to treat antenatal depression.
- Reference Group: Mothers not using the NUTRIMUM micronutrients or medications.
What Were the Results?
- Birth Outcomes Are Comparable to the Reference Group
Mothers taking micronutrients had birth outcomes similar to the reference group, with no increased risks of preterm births, low birth weight, or delivery complications. The one group difference that was identified favoured a better outcome for the micronutrient-exposed infants. There was significantly less post-partum haemorrhage in vaginal births for the micronutrient exposed mothers compared with the reference group (7.7% versus 30%). The outcomes for the micronutrient-exposed infants were also on par or better than national averages in Aotearoa NZ. This means that the risks conferred to the infant based on the mother’s history of depression were possibly mitigated by the micronutrients. This is good news. - Micronutrients Outperformed Antidepressants
Compared to the MED group, the MN group had significantly better results:- Preterm births were lower (5.5% in MN vs. 20% in MED).
- Infants in the MN group were longer at birth (52.2 cm vs. 50 cm in MED).
- Rates of infant resuscitation were lower (14.5% in MN vs. 45% in MED).
- Duration of Use Matters
Longer exposure to micronutrients correlated with increased infant weight and length, indicating a potential dose-response effect.
What About the Costs of Birth Complications?
A major consideration for any treatment is cost. The micronutrients used in the NUTRIMUM trial cost around NZ$200 per month. Six-month treatment would cost about NZ$1200, a substantial barrier for many pregnant people. However, when considering healthcare savings for the public health care system, the story changes.
For example, preterm births (32–36 weeks) are estimated to cost ~NZ$28,000 per infant, accounting for birth, neonatal care, delivery costs, early intervention, schooling, primary and secondary care to 18 years. The risk of a preterm birth for a birthing person with untreated depression is about 15%. Therefore, the cost savings per birth to a birthing person with antenatal depression treated with micronutrients is ((15%-5.5%) * $28,000) – $1200 = NZ$1460.
With 60,000 live births in NZ per year, and about 12% of birthing persons in NZ experiencing antenatal depression, potential cost savings per annual cohort using micronutrients for these individuals is substantial: 60,000 births * 12% * $1460 = ~NZ$10.5M.
This figure highlights the economic and medical value of exploring micronutrients as a standard treatment option to mitigate the negative effects of depression. NZ$10.5M per annual cohort likely underestimates potential cost savings as benefits were also observed in other costly health issues, such as maternal depression, post-partum haemorrhaging, and infant resuscitation. This is the kind of cost savings our health system should reflect on in guidelines and planning.
What Does This Mean for You?
If you’re pregnant and feeling emotionally distressed, talk to your midwife or healthcare provider about your symptoms. You may want to explore whether broad-spectrum micronutrients could be an option for you.
Nutritional approaches to mental health support are an emerging area of research, and the NUTRIMUM trial adds to a growing body of evidence supporting their safety and efficacy. By reducing the risks of poor birth outcomes, micronutrients may offer a potential alternative to antidepressant medications during and after pregnancy.
However, supplementation is not a replacement for nutritious food. But these data illustrate through a controlled study the positive effect that additional nutrients can have on outcomes as proof of principle that the nutritional environment is inadequate for some pregnancies. Supporting individuals to eat nutrient dense food during pregnancy should be one goal. In turn, research could evaluate the potential cost savings obtained through supporting birthing persons to eat more nutrient dense foods during pregnancy, with supplementation as an additional support, on both mental and physical health outcomes.
To read to full article check out the recent publication in the Journal of Clinical Psychopharmacology.
For other finding from the NUTRIMUM trial, check out a post to The Conversation.
