Nutrition in Pregnancy: Optimising Maternal Diet and Fetal Adaptations to Altered Nutrient Supply

Development of a novel Periconceptual Nutrition Score (PENS) to examine the relationship between maternal dietary quality and fetal growth

BACKGROUND

Maternal nutrition may influence intrauterine fetal development. To date, the relationship between contemporary European dietary guidelines and fetal growth has not been examined.

AIMS

To develop a novel Periconceptual Nutrition Score (PENS) to assess maternal dietary quality in early pregnancy and examine its relationship with fetal growth.

STUDY DESIGN

Women were recruited conveniently at their first clinic visit and completed a supervised four day retrospective diet history. The PENS was developed using European Food Safety Authority recommended dietary intakes for pregnancy. The relationship between PENS and fetal growth was examined.

SUBJECTS

Women with a singleton pregnancy.

OUTCOME MEASURES

Birthweight, small for gestational age (SGA), neonatal head circumference.

RESULTS AND CONCLUSIONS

Of the 202 women, the mean age was 32.2 ± 5.0 years and 44.6% were nulliparas. The mean PENS was 9.4 ± 3.1. On multivariable regression, there was a positive relationship between the PENS and birthweight (beta = 45.3, 95%CI 14.8-75.9, P = 0.002) and neonatal head circumference (beta = 0.12, 95%CI 0.01-0.23, P = 0.03). Compared with the lowest PENS quartile, the mean birthweight was increased in the highest quartile (Mean difference 328 g, P = 0.02). The incidence of SGA was 16.4% (n = 10/61) in the lowest PENS quartile compared to 6.5% (n = 9/139) in the top three quartiles (P = 0.03). Thus, higher maternal dietary quality was associated with increased intrauterine fetal growth. The PENS is potentially useful in identifying those women before or during pregnancy who may benefit from dietary interventions that may optimise fetal growth. It may also be useful in tracking maternal dietary quality during pregnancy.

Maternal dyslipidaemic diet induces sex-specific alterations in intestinal function and lipid metabolism in rat offspring

This study investigated the effects of a maternal dyslipidaemic (DLP) diet on lipid metabolism, microbial counts in faeces and hepatic and intestinal morphology in rat offspring with respect to sex during different phases of life. Wistar rats (dams) were fed a control (CTL) or DLP during gestation and lactation. After weaning, CTL and DLP offspring were fed a standard diet. The effects of a maternal DLP on body composition, biochemical parameters, faecal microbiota and intestinal and hepatic histomorphometric characteristics in rat offspring were evaluated at 30 and 90 d of age. The DLP diet during gestation and lactation caused lower birth weight and a greater weight gain percentage at the end of the 90-d period in both male and female offspring. Female pups from DLP dams had higher liver fat levels compared with CTL (P≤0·001) at 90 d of age. Males from DLP dams had greater visceral fat weight and lower Lactobacillus spp. faecal counts at 90 d of age (P≤0·001) as well as lower faecal fat excretion (P≤0·05) and Bacteroides spp. faecal counts (P≤0·001) at 30 d of age when compared with pups from CTL dams. However, both dams and DLP pups showed damage to intestinal villi. A maternal DLP alters intestinal function and lipid metabolism in a sex-specific manner and is a potential predisposing factor for health complications in offspring from the juvenile period to the adult period.

Perinatal Nutrition and Programmed Risk for Neuropsychiatric Disorders: A Focus on Animal Models

Maternal nutrition is critically important for fetal development. Recent human studies demonstrate a strong connection between diet during pregnancy and offspring risk for neuropsychiatric disorders including depression, anxiety, and attention-deficit/hyperactivity disorder. Animal models have emerged as a crucial tool for understanding maternal nutrition's contribution to prenatal programming and the later development of neuropsychiatric disorders. This review highlights preclinical studies examining how maternal consumption of the three macronutrients (protein, fats, and carbohydrates) influence offspring negative-valence behaviors relevant to neuropsychiatric disorders. We highlight the translational aspects of animal models and so examine exposure periods that mirror the neurodevelopmental stages of human gestation. Because of our emphasis on programmed changes in neurobehavioral development, studies that continue diet exposure until assessment in adulthood are not discussed. The presented research provides a strong foundation of preclinical evidence of nutritional programming of neurobehavioral impairments. Alterations in risk assessment and response were observed alongside neurodevelopmental impairments related to neurogenesis, synaptogenesis, and synaptic plasticity. To date, the large majority of studies utilized rodent models, and the field could benefit from additional study of large-animal models. Additional future directions are discussed, including the need for further studies examining how sex as a biological variable affects the contribution of maternal nutrition to prenatal programming.

Effect of Adherence to a Mediterranean Diet and Olive Oil Intake during Pregnancy on Risk of Small for Gestational Age Infants

To quantify the effect of a Mediterranean dietary pattern, as well as the consumption of olive oil (OO), on the risk of having a small for gestational age infants (SGA), a matched case-control study was conducted in Spain. Dietary intake during pregnancy was assessed using a validated food frequency questionnaire. Three indices were used to evaluate the adherence to Mediterranean diet (MD) (Predimed, Trichopoulou and Panagiotakos). Crude odds ratios (cOR) and adjusted odds ratios (aOR) and their 95% confidence intervals (CI) were estimated using conditional logistic regression models. Results were stratified by severity of SGA: moderate (percentiles 6–10), and severe (percentiles ≤5). For moderate, four or more points in the Predimed´s index was associated with a 41% reduction of having SGA compared with women with a score ≤3, aOR = 0.59 (95% CI 0.38–0.98); for severe, the reduction in risk was not statistically significant. Similar results were found when the other MD indexes were used. An intake of OO above 5 g/day was associated with a lower risk of SGA (aOR = 0.53, 95% CI 0.34–0.85); statistical significance was observed for moderate SGA (aOR = 0.53, 95% CI 0.30–0.96), but not for severe SGA (aOR = 0.51, 95% CI 0.24–1.07), although the magnitude of ORs were quite similar. Adherence to a MD and OO intake is associated with a reduced risk of SGA.

Dietary and Physical Activity Behaviours in African Migrant Women Living in High Income Countries: A Systematic Review and Framework Synthesis

Dietary and physical activity behaviours during preconception and in pregnancy are important determinants of maternal and child health. This review synthesised the available evidence on dietary and physical activity behaviours in pregnant women and women of childbearing age women who have migrated from African countries to live in high income countries. Searches were conducted on Medline, Embase, PsycInfo, Pubmed, CINAHL, Scopus, Proquest, Web of Science, and the Cochrane library. Searches were restricted to studies conducted in high income countries and published in English. Data extraction and quality assessment were carried out in duplicate. Findings were synthesised using a framework approach, which included both a priori and emergent themes. Fourteen studies were identified; ten quantitative and four qualitative. Four studies included pregnant women. Data on nutrient intakes included macro- and micro-nutrients; and were suggestive of inadequacies in iron, folate, and calcium; and excessive sodium intakes. Dietary patterns were bicultural, including both Westernised and African dietary practices. Findings on physical activity behaviours were conflicting. Dietary and physical activity behaviours were influenced by post-migration environments, culture, religion, and food or physical activity-related beliefs and perceptions. Further studies are required to understand the influence of sociodemographic and other migration-related factors on behaviour changes after migration.

Ayurveda and the science of aging

Since time immemorial, humanity has been concerned with developing and preserving youthful vigor, and extending longevity by stopping or delaying the aging process. By 2030, one in five of the world population will be over 65 years old. Longevity and old age are accompanied with a variety of health challenges and population studies indicate that the elderly will use between three to five times more healthcare services compared to the younger population. Modern medicine has made a great deal of progress in understanding the aging process and in controlling age-associated health issues including heart attacks, strokes, diabetes, cancer, senility, and arthritis. Thus, every individual is now looking forward to a youthful, productive lifespan of 100 or more years filled with unlimited health and opportunity. Research by aging experts is focused on ways to go against the natural order of the aging process in order to delay it. Interventions include among other things anti-aging pills, restricted food consumption and cloning body parts to stay young and delay biological aging. Ayurveda, one of the world's most authoritative mind-body-spirit medicinal systems, offers various concepts of the aging process. This system of medicine includes therapies for healthy aging so as to create an optimal health and lengthen an individual's healthspan by living in harmony with nature. This review will explore various aspects of aging and longevity by comparing the science of aging as defined by modern medicine with the Ayurvedic treatise of Jara and Vriddhavastha.

Birthweight, Type 2 Diabetes Mellitus, and Cardiovascular Disease: Addressing the Barker Hypothesis With Mendelian Randomization

BACKGROUND

Low birthweight has been associated with a higher risk of hypertension, type 2 diabetes mellitus (T2D), and cardiovascular disease. The Barker hypothesis posits that intrauterine growth restriction resulting in lower birthweight is causal for these diseases, but causality is difficult to infer from observational studies.

METHODS

We performed regression analyses to assess associations of birthweight with cardiovascular disease and T2D in 237 631 individuals from the UK Biobank. Further, we assessed the causal relationship of such associations using Mendelian randomization.

RESULTS

In the observational analyses, birthweight showed inverse associations with systolic and diastolic blood pressure (β, -0.83 and -0.26; per raw unit in outcomes and SD change in birthweight; 95% confidence interval [CI], -0.90 to -0.75 and -0.31 to -0.22, respectively), T2D (odds ratio, 0.83; 95% CI, 0.79-0.87), lipid-lowering treatment (odds ratio, 0.84; 95% CI, 0.81-0.86), and coronary artery disease (hazard ratio, 0.85; 95% CI, 0.78-0.94), whereas the associations with adult body mass index and body fat (β, 0.04 and 0.02; per SD change in outcomes and birthweight; 95% CI, 0.03-0.04 and 0.01-0.02, respectively) were positive. The Mendelian randomization analyses indicated inverse causal associations of birthweight with low-density lipoprotein cholesterol, 2-hour glucose, coronary artery disease, and T2D and positive causal association with body mass index but no associations with blood pressure.

CONCLUSIONS

Our study indicates that lower birthweight, used as a proxy for intrauterine growth retardation, is causally related with increased susceptibility to coronary artery disease and T2D. This causal relationship is not mediated by adult obesity or hypertension.

Skeletal Muscle Damage in Intrauterine Growth Restriction

Intrauterine growth restriction (IUGR) represents a rate of fetal growth that is less than average for the population and the growth potential of a specific infant. IUGR produces infants who are small for gestational age (SGA) but also appropriate for gestational age (AGA). It refers to growth less than expected for gestational age and is most often under 10th percentiles for age. It develops during the late second and third trimesters of gestation. The etiology of IUGR is multifactorial. One of the most important factors which leads to IUGR is a decrease of nutrients and oxygen delivered to the fetus by the placenta. The growth of adipose tissue and skeletal muscle is limited by the declined fetal nutrient supply later in gestation. IUGR affects about 24% of babies born in developing countries. Worldwide, IUGR is the second cause of perinatal morbidity and mortality behind the premature birth and a major predisposing factor to metabolic disorders throughout postnatal life, even at adult age. Skeletal muscle represents about 35-40% of the body mass and plays an essential role in metabolic homeostasis, being responsible for 65% of fetal glucose consumption. A reduction in skeletal muscle growth characterizes IUGR fetuses compared to normal weight neonates. The decrease in muscle mass is not compensated after birth and persists until adulthood. This is a review of the literature, a neonatological, clinical point of view on the effects of IUGR on striated muscles. The available studies on this subject are currently the results of experimental research on animals, and information about the human fetus and newborn are scarce.

The Maternal Gut Microbiome During Pregnancy

The gut microbiome is a critical component of an individual's metabolism and overall health. The prenatal period is marked by unique inflammatory and immune changes that alter maternal gut function and bacterial composition as the pregnancy advances. The composition of the maternal gut microbiome contributes to obstetric outcomes with long-term health sequelae for mother and child. Estrogen and progesterone also have an impact on gut function, especially during the prenatal period. These physiologic changes in pregnancy allow for adjustments in maternal metabolism and weight necessary to support the pregnancy. Normal hormonal, metabolic, and immunologic changes to the maternal gut microbiome throughout the prenatal period are reviewed, including relevant implications for nurses providing care for pregnant women.

Association between Vitamin Intake during Pregnancy and Risk of Small for Gestational Age

Pregnancy increases the requirements of certain nutrients, such as vitamins, to provide nutrition for the newborn. The aim was to analyze the association between dietary intake of vitamins during pregnancy and risk of having a small for gestational age (SGA) newborn. A matched case-control study was conducted (518 cases and 518 controls of pregnant women) in Spain. Dietary vitamin intake during pregnancy was assessed using a validated food frequency questionnaire, categorized into quintiles. Odds ratios (ORs) and their 95% confidence intervals (CI) were estimated with conditional regression logistic models. A protective association was observed between maternal dietary intake of vitamins A and D and SGA. For vitamin B3 and B6, the observed protective effect was maintained after adjusting for potential confounding factors. For vitamin B9, we found only an effect in quintiles 3 and 4 (OR = 0.64; 95% CI, 0.41-1.00; OR = 0.58; 95% CI, 0.37-0.91). Protective effect for vitamin B12 was observed in 4th and 5th quintiles (OR = 0.61; 95% CI, 0.39-0.95; OR = 0.68; 95% CI, 0.43-1.04). No associations were detected between dietary intake of vitamins B2, E and C intake and SGA. Our results suggest a positive association between dietary vitamin intake during pregnancy and the weight of the newborn, although more studies are necessary and there could be a ceiling effect for higher intakes of some vitamins cannot be discarded.

A qualitative study exploring midwives' perceptions and knowledge of maternal obesity: Reflecting on their experiences of providing healthy eating and weight management advice to pregnant women

Midwives are responsible for providing advice regarding the complex issues of healthy eating and weight management during pregnancy. This study utilised an inductive data-driven thematic approach in order to determine midwives' perceptions, knowledge, and experiences of providing healthy eating and weight management advice to pregnant women. Semistructured interviews with 17 midwives were transcribed verbatim and data subjected to thematic analysis. The findings offer insight into the challenges facing midwives in their role trying to promote healthy eating and appropriate weight management to pregnant women. Three core themes were identified: (a) "If they eat healthily it will bring their weight down": Midwives Misunderstood; (b) "I don't think we are experienced enough": Midwives Lack Resources and Expertise; and (c) "BMI of 32 wouldn't bother me": Midwives Normalised Obesity. The midwives recognised the importance of providing healthy eating advice to pregnant women and the health risks associated with poor diet and obesity. However, they reported the normalisation of obesity in pregnant women and suggested that this, together with their high workload and lack of expertise, explained the reasons why systematic advice was not in standard antenatal care. In addition, the current lack of UK clinical guidance, and thus, possibly lack of clinical leadership are also preventing delivery of tailored advice. Implementation literature on understanding the barriers to optimal health care delivery and informing clinical practice through research evidence needs to be further investigated in this field. This study has recommendations for policy makers, commissioners, service providers, and midwives.

Validation of a Smartphone Image-Based Dietary Assessment Method for Pregnant Women

Image-based dietary records could lower participant burden associated with traditional prospective methods of dietary assessment. They have been used in children, adolescents and adults, but have not been evaluated in pregnant women. The current study evaluated relative validity of the DietBytes image-based dietary assessment method for assessing energy and nutrient intakes. Pregnant women collected image-based dietary records (via a smartphone application) of all food, drinks and supplements consumed over three non-consecutive days. Intakes from the image-based method were compared to intakes collected from three 24-h recalls, taken on random days; once per week, in the weeks following the image-based record. Data were analyzed using nutrient analysis software. Agreement between methods was ascertained using Pearson correlations and Bland-Altman plots. Twenty-five women (27 recruited, one withdrew, one incomplete), median age 29 years, 15 primiparas, eight Aboriginal Australians, completed image-based records for analysis. Significant correlations between the two methods were observed for energy, macronutrients and fiber (r = 0.58–0.84, all p < 0.05), and for micronutrients both including (r = 0.47–0.94, all p < 0.05) and excluding (r = 0.40–0.85, all p < 0.05) supplements in the analysis. Bland-Altman plots confirmed acceptable agreement with no systematic bias. The DietBytes method demonstrated acceptable relative validity for assessment of nutrient intakes of pregnant women.

A Brief Tool to Assess Image-Based Dietary Records and Guide Nutrition Counselling Among Pregnant Women: An Evaluation

Background

Dietitians ideally should provide personally tailored nutrition advice to pregnant women. Provision is hampered by a lack of appropriate tools for nutrition assessment and counselling in practice settings. Smartphone technology, through the use of image-based dietary records, can address limitations of traditional methods of recording dietary intake. Feedback on these records can then be provided by the dietitian via smartphone. Efficacy and validity of these methods requires examination.

Objective

The aims of the Australian Diet Bytes and Baby Bumps study, which used image-based dietary records and a purpose-built brief Selected Nutrient and Diet Quality (SNaQ) tool to provide tailored nutrition advice to pregnant women, were to assess relative validity of the SNaQ tool for analyzing dietary intake compared with nutrient analysis software, to describe the nutritional intake adequacy of pregnant participants, and to assess acceptability of dietary feedback via smartphone.

Methods

Eligible women used a smartphone app to record everything they consumed over 3 nonconsecutive days. Records consisted of an image of the food or drink item placed next to a fiducial marker, with a voice or text description, or both, providing additional detail. We used the SNaQ tool to analyze participants’ intake of daily food group servings and selected key micronutrients for pregnancy relative to Australian guideline recommendations. A visual reference guide consisting of images of foods and drinks in standard serving sizes assisted the dietitian with quantification. Feedback on participants’ diets was provided via 2 methods: (1) a short video summary sent to participants’ smartphones, and (2) a follow-up telephone consultation with a dietitian. Agreement between dietary intake assessment using the SNaQ tool and nutrient analysis software was evaluated using Spearman rank correlation and Cohen kappa.

Results

We enrolled 27 women (median age 28.8 years, 8 Indigenous Australians, 15 primiparas), of whom 25 completed the image-based dietary record. Median intakes of grains, vegetables, fruit, meat, and dairy were below recommendations. Median (interquartile range) intake of energy-dense, nutrient-poor foods was 3.5 (2.4-3.9) servings/day and exceeded recommendations (0-2.5 servings/day). Positive correlations between the SNaQ tool and nutrient analysis software were observed for energy (ρ=.898, P<.001) and all selected micronutrients (iron, calcium, zinc, folate, and iodine, ρ range .510-.955, all P<.05), both with and without vitamin and mineral supplements included in the analysis. Cohen kappa showed moderate to substantial agreement for selected micronutrients when supplements were included (kappa range .488-.803, all P ≤.001) and for calcium, iodine, and zinc when excluded (kappa range .554-.632, all P<.001). A total of 17 women reported changing their diet as a result of the personalized nutrition advice.

Conclusions

The SNaQ tool demonstrated acceptable validity for assessing adequacy of key pregnancy nutrient intakes and preliminary evidence of utility to support dietitians in providing women with personalized advice to optimize nutrition during pregnancy.