General Conclusions From Current Research

Several studies have suggested the correlation between nutrition and maternal stressors and the overall growth of the child’s neurodevelopment and behavior. However, research is still needed due to inconclusive results. Due to some different study designs, sample sizes, and other factors, there are a few studies that provide weaker results while others have more promising results. Each study has a key focus in which how it links to the infants neurocognitive growth. All information and results contribute to the overall growing body of research.

Synthesized Finding # 1: Breast Milk vs Formula Milk

Proper nutrition in the early stages of life are essential for growth. In a longitudinal and cross-sectional study design organized by Deoni, S. , Dean III, D. , Joelson, S. , O'Reagan, J. , & Schneider, N. (2017), the differences of nutrition between human breast milk and formula milk presented results to help explain the neurodevelopment in infants. While an observational study by Zhang et al. (2018) showed the impact of maternal nutritional supplementation with a breastfeeding support program and duration of feeding to explain the neurodevelopment. A last study by Anderson and Burggren (2014), proposed a different hypothesis based off the Deoni et al. (2017) study. This systematic review believes that the neurocognitive differences between breastfed and formula-fed infants might be caused by the untimely introduction to cow's milk by two years old.

Deoni et al. (2017) had 500 plus participants, but ended up with a total of 452 datasets. These datasets were neuroimages, from an MRI, that were captured throughout infancy and early childhood to determine the myelin water fraction (MWF) or morphology and myelination of the brain (Deoni et al. , 2017). The Zhang et al. (2018) study focused on the offspring of 204 Vietnamese women who completed a randomized controlled trial. The trial consisted of a group that received maternal milk supplementation with a breastfeeding support program in conjunction with duration of the feedings compared to a control group with standard care and information. Results were measured from the last trimester to 12 weeks postpartum and at 30 months postpartum (Zhang et al. , 2018). The Anderson and Burggren (2014) review used the same datasets as Deoni et al. (2017) and compared the datasets and test scores from a different perspective.

Of the datasets, from Deoni et al. (2017), there were four groups, breast milk, and three different formula milks. All parts of the brain were assessed such as the frontal, temporal parietal, occipital, cerebellar, and corpus callosum. Further assessment tests such as the Mullen Scales of Early Learning and Wechsler Intelligence Scale for Children were used to evaluate general cognitive ability and skills depending on the age. The Zhang et al. (2018) study uses questionnaires filled out by the mothers to acquire information pertaining to their child such as the age and when they stopped breast feeding. To assess the infants neurodevelopment they used two tools. The Ages and Stages Questionnaires and the Bayley Scales of Infant and Toddler Development. These test assesses the child’s motor skills, communication, problem solving and personal social developments ( Zhang et al. , 2018). Anderson and Burggren (2014) simply focused on the weaknesses and inconsistent data with the Deoni et al. (2017) study and applied their own assumptions to it. They believe the mothers introduced cow’s milk prematurely prior to two years old which influenced the brain development. The Deoni et al. (2017) results show the children who were breastfed presented a period of rapid development at 2 years old, as well as an overall increase in myelin content.

The formula-fed group presented an increased MWF before 1 year of age, and then had a decreased rate of MWF development between 1 and 2 years of age, and never were able to reach the level of MWF as the breastfed children (Deoni et al. , 2017). Results are compared on graphs. The Zhang et al. (2018) study results showed that MMS from the last trimester to 12 weeks, along with the support program had significantly associated with extended breastfeeding duration improved neurodevelopment in cognitive and motor functions at 30 months of age, when compared with the control group who had standard care. Anderson and Burggren (2014) believe that data from Deoni et al. (2017) tells another compelling story which suggests that infants may be transitioning prematurely to cow's milk, which may lack adequate nutrients for their developing brains (Anderson & Burggren, 2014). Overall, results have helped present that proper breastfeeding and duration throughout infancy can potentially lead to adequate brain growth compared to formula milk, but results still remain unclear.

Synthesized Finding # 2: Roles of Micronutrients

Specific micronutrients are essential in proper neurocognitive growth and behavior. A study by Freedman, R. , Hunter, S. K. , Hoffman, C. , & Hoffman, M. C. (2018) focused on the certain micronutrients that contribute to the infants overall development and mental illness. The micronutrients in the study include, folic acid, omega-3 fatty acids (fish oil), phosphatidylcholine and vitamins A and D. The Monk, C. , Georgieff, M. K. , & Osterholm, E. A. (2013) review suggest that unhealthy maternal diet affects children's future brain development. They mention micronutrients and the benefits of what each nutrient does. They include fats, protein, zinc, iron, and choline. In the Veena, S. R. , Gale, C. R. , Krishnaveni, G. V. , Kehoe, S. H. , Srinivasan, K. , & Fall, C. H. (2016) review, the mother is the only source of nutrition for infant neurodevelopment. The micronutrients they examined include vitamins D, B12, folate and iron and the macronutrient carbohydrate, protein and fat.

Freedman et al. (2018) identified four types of prenatal dietary interventions to promote neurodevelopment and decrease risks for future mental illness. For folic acid, 311 women participants were in a randomized control trial (RCT) and divided into 4 groups. For fish oil, 543 women were in an RCT split into 2 groups. Phosphatidylcholine had women in the first double blind controlled trial and then 50 in a second double blind control trial. Vitamin A had 12,000 women participants, which were enrolled in a health plan and vitamin D had 430 participants. Veena et al. (2016) took 38 observational studies and RCTs pertaining to nutrients and development and compared results from each one. The results from the Freedman et al. (2018) study suggest folic acid benefits development of the brain, child behavior and cognition, while higher levels of vitamins A and D improve neurodevelopment and decrease risk for mental illnesses such as schizophrenia.

That being said, folic acid results were not able to show it to prevent mental illnesses. Omega-3 fatty acids (fish oil) increase the risk for future mental illnesses such as schizophrenia and ADHD symptoms. Some benefits of fish oil is that it decreases the risk of premature birth. . Lastly, phosphatidylcholine has been found to help enable the development of the infant's brain and childhood behavior. Amongst the comparisons of the exemplar studies, Veena et al. (2016) found evidence correlating low micronutrient status to fetal brain development. Low levels of vitamin D, folate and B12, during pregnancy, links to poorer cognitive function. Each micronutrient plays a major role in growth. According to Monk et al. (2013) fats are a kind of macronutrient which correlates to neurodevelopment. They are “essential in cell membranes, intracellular communication, signal transduction, and monoamine metabolism, thus affecting neurodevelopment” (Monk et al. , 2013). Protein is typically used by the body for tissue development. The lack of macronutrients during fetal life can ultimately decrease growth. The data on a deficiency in zinc reveal delays in motor development. Lastly, choline is shown to impact methylation and myelin neurotransmitters as well as cell proliferation (Monk et al. 2013 ). Overall, the information shows prenatal exposure to poor nutrient may be linked with decreased neurocognitive development. Nutrition and growth factors play a large role in regulating the brain’s development. Adequate nutrient is important to offspring cognitive development. Further research is still need.

Synthesized Finding # 3: Influences of Obesity During Gestation

Metabolic pathologies, such as body mass index, can contribute to increasing the risk factors that may impair brain function and development during infancy. Torres-Espinola, F. J. , Berglund, S. K. , García-Valdés, L. M. , Segura, M. T. , Jerez, A. , Campos, D. , (2015). suggests that maternal weight plays a role in impacting their offsprings development. Duffany, K. , McVeigh, K. , Kershaw, T. , Lipkind, H. , & Ickovics, J. (2016) focuses on mothers who were obese (>200lbs) prior to pregnancy and assesses the risks for delayment of neurodevelopment.

The Torres-Espinola et al. (2015) study contained 331 mothers from Spain which were divided up into four groups based on their gestational BMI. These groups include overweight, obese, gestational diabetic and normal weight. The infants were assessed using the Bayley Scales of neurodevelopment at 6 months old and then again at 18 months old. Duffany et al. (2016) was a retrospective cohort study using a very large sample size of 541,816 participants. The sample size came from a population based data warehouse in New York which was link with birth and early intervention data (Duffany et al. , 2016).

Results of Torres-Espinola et al. (2015) found significant evidence at 6 months. A post hoc test presented higher scores in the obese mothers compared to the other groups. Post hoc tests are for confirming where the differences occurred between groups. Assessed again at 18 months, the infants of the obese group had a rapid decrease in scores while the rest of the groups showed better scores. Duffany et al. (2015) had results that revealed infants of obese mothers were more likely to have some sort of delayment physically and cognitively.

Results from both studies have shown impairment or delay of neurodevelopment with mothers who happen to be considered obese. This information adds to the growing evidence and research of the correlation between maternal obesity and neurodevelopment.