Methodological aspects of the study of dietary patterns during pregnancy and maternal and infant health outcomes. A systematic review

Maternal dietary patterns as predictors of neonatal body composition in Ethiopia: the IABC birth cohort study

BACKGROUND

Malnutrition during pregnancy is associated with adverse birth outcomes, but the importance of maternal diet during pregnancy for neonatal body composition remains inconclusive. This study investigated the role of maternal diet during pregnancy for neonatal body composition in the Ethiopian iABC birth cohort.

METHODS

The data stemmed from the first visit at birth comprising 644 mother-child pairs. Shortly after delivery, the diet of the last week of pregnancy was assessed by a non-quantitative and non-validated 18-items food frequency questionnaire. Multiple imputation was used to handle missing data. Twin births and implausible values were excluded from analysis (n = 92). The Dietary Diversity Score (0-9 points) was constructed and exploratory dietary patterns were derived via principal component analysis. Neonatal fat mass and fat-free mass were assessed by air-displacement plethysmography. The associations of maternal Dietary Diversity Score and exploratory dietary patterns with gestational age, neonatal anthropometric measures and body composition were investigated using multiple-adjusted linear regression analysis.

RESULTS

In this cohort (n = 552), mean ± standard deviation (SD) mother's age was 24.1 ± 4.6 years and the median maternal Dietary Diversity Score was 6 (interquartile range = 5-7). An 'Animal-source food pattern' and a 'Vegetarian food pattern' were identified. The mean ± SD birth weight was 3096 ± 363 g and gestational age was 39.0 ± 1.0 weeks. Maternal adherence to the Animal-source food pattern, but not Vegetarian food pattern, was related to birth weight [79.5 g (95% confidence interval (CI): -14.6, 173.6)]. In the adjusted model, adherence to the Animal-source food pattern was associated with higher neonatal fat-free mass [53.1 g (95% CI: -20.3, 126.6)], while neonates of women with high compared to low adherence to Dietary Diversity Score and Vegetarian food pattern had higher fat mass [19.4 g (95% CI: -7.4, 46.2) and 33.5 g (95% CI: 2.8, 64.1), respectively].

CONCLUSIONS

In this Ethiopian population, maternal diet during pregnancy was associated with neonatal body composition. The analysis of body composition adds important detail to the evaluation of maternal dietary habits for the newborn constitution.

Prenatal adherence to the Mediterranean diet decreases the risk of having a small-for-gestational-age baby, ECLIPSES study

There is little evidence regarding the role that consuming a Mediterranean diet (MedDiet) during pregnancy plays in foetal growth. We therefore examined the relationship between maternal MedDiet adherence during pregnancy and anthropometric measures and small-for-gestational-age (SGA) at birth in a Spanish population on the north-eastern Mediterranean coast of Spain. Prospective analysis involved 614 mother–newborn pairs from the ECLIPSES study. Diet during pregnancy was assessed using a validated food frequency questionnaire, and a relative MedDiet score (rMedDiet) was calculated. Neonatal information, including weight, length, head circumference and SGA (< 10th percentile) at birth, was recorded. Multivariable logistic regression analyses were performed. The mean rMedDiet score was 9.8 (SD 2.1), ranging from 5 to 16 points. In the sample, 45% of the women had low (≤ 9 points), 32% had medium (10–11 points), and 22% had high (≥ 12 points) adherence to the rMedDiet. There was no association between rMedDiet and birth weight, length, head circumference or anthropometric indices (weight/length ratio and ponderal index). Pregnant women with a high rMedDiet score had a lower risk of delivering a SGA baby for weight (high vs low, OR = 0.36; 95% CI 0.16–0.79) and head circumference (high vs low, OR = 0.39; 95% CI 0.18–0.86), and a nonsignificant decrease in risk of SGA for length (high vs low, OR = 0.57; 95% CI 0.28–1.17). In conclusion, closer adherence to the MedDiet during pregnancy may have beneficial effects on foetal growth.

Maternal Diet Influences Fetal Growth but Not Fetal Kidney Volume in an Australian Indigenous Pregnancy Cohort

Suboptimal nutrition during pregnancy is recognised as a significant modifiable determinant in the development of chronic disease in offspring in later life. The current study aimed: (i) to assess the dietary intakes of pregnant Indigenous Australian women against national recommendations and (ii) to investigate the associations between maternal nutrition during pregnancy and the growth of the offspring, including kidney development in late gestation in the Gomeroi gaaynggal cohort (n = 103). Maternal dietary intake in the third trimester was assessed using the Australian Eating Survey Food Frequency Questionnaire. Estimated fetal weight (EFW) and kidney size were obtained by ultrasound. Birth weight was retrieved from hospital birth records. Of the five key nutrients for optimal reproductive health (folate, iron, calcium, zinc and fibre), the nutrients with the highest percentage of pregnant women achieving the nutrient reference values (NRVs) were zinc (75.7%) and folate (57.3%), whereas iron was the lowest. Only four people achieved all NRVs (folate, iron, calcium, zinc and fibre) important in pregnancy. Sodium and saturated fat intake exceeded recommended levels and diet quality was low, with a median score of 28 out of 73 points. After adjusting for smoking and pre-pregnancy body mass index, only maternal intake of retinol equivalents and the proportion of energy from nutrient-dense or energy-dense, nutrient-poor (EDNP) foods were associated with fetal growth. EFW decreased by 0.13 g and birth weight decreased by 0.24 g for every µg increase in maternal dietary retinol intake. Interestingly, EFW, but not actual birth weight, was positively associated with percentage energy from nutrient dense foods and negatively associated with percentage energy from EDNP foods. Dietary supplement usage was associated with increased birthweight, most significantly iron and folate supplementation. Current dietary intakes of pregnant Australian women from this cohort do not align with national guidelines. Furthermore, current findings show that maternal retinol intake and diet composition during pregnancy can influence fetal growth, but not fetal kidney growth in late gestation. Strategies that aim to support and optimise nutrient intakes of Indigenous pregnant women are urgently needed. Future studies with long-term follow-up of the children in the current cohort to assess renal damage and blood pressure are imperative.

Maternal profile according to Mediterranean diet adherence and small for gestational age and preterm newborn outcomes

OBJECTIVE

The objective was to evaluate maternal Mediterranean diet (MD) pattern adherence during pregnancy and its association with small for gestational age (SGA) and preterm birth. A secondary objective of the current study was to describe the sociodemographic, lifestyle and obstetric profile of the mothers studied as well as the most relevant paternal and newborn characteristics.

DESIGN

The current study is a two-phase retrospective population-based study of maternal dietary habits during pregnancy and their effect on newborn size and prematurity. The descriptive first phase examined maternal dietary habits during pregnancy along with the maternal sociodemographic, lifestyle and obstetric profile in a cross-sectional period study. In the second phase, newborn outcomes were evaluated in a nested case-control study. Adherence to MD during pregnancy was measured with the Spanish version of Kidmed index.

SETTING

Obstetrics ward of the La Fe Hospital in Valencia.

PARTICIPANTS

All mother-child pairs admitted after delivery during a 12-month period starting from January 2018 were assessed for eligibility. A total of 1118 provided complete outcome data after signing informed consent.

RESULTS

14·5 % met the criteria of poor adherence (PA); 34·8 %, medium adherence (MA); and 50·7 %, optimal adherence (OA). Medium adherence to MD was associated in the adjusted scenarios with a higher risk of giving birth to a preterm newborn. No association was found between MD adherence and SGA.

CONCLUSIONS

Early intervention programmes geared towards pregnant women, where women were aided in reaching OA to MD, might reduce the risk of preterm newborn.

Prenatal dietary exposures and offspring body size from 6 months to 18 years: A systematic review

BACKGROUND

In utero dietary exposures may influence childhood obesity.

OBJECTIVES

To evaluate the relationship between prenatal dietary exposures and offspring body size from 6 months to 18 years.

DATA SOURCES

Articles were identified in PubMed and Web of Science (January 2010-March 2018) using the PRISMA guidelines. Additional studies were identified through a reference review of articles that met the inclusion criteria and related reviews.

STUDY SELECTION

Prospective cohort studies that assessed dietary patterns, foods, macronutrients, or beverages during healthy pregnancy and offspring body size. The extraction of articles was done using predefined data fields.

SYNTHESIS

One author extracted all information and evaluated bias with the NHLBI's Quality Assessment Tool.

RESULTS

A total of 851 research articles were evaluated. Twenty-one studies assessing dietary patterns, macronutrients, foods, and beverages met inclusion criteria. Consumption of a Mediterranean dietary pattern during pregnancy was associated with reduced body size, while refined carbohydrates were associated with offspring obesity. No association was observed between data-driven dietary patterns and offspring body size, as well as a pro-inflammatory diet pattern and offspring body size. Mixed and null findings were observed for the relationship between total carbohydrates, n-3 polyunsaturated fatty acids, protein, sugar-sweetened beverages, and artificially sweetened beverages and offspring body size.

CONCLUSIONS

Adhering to a Mediterranean diet and limiting refined carbohydrates during pregnancy may influence offspring body size between 6 months and 18 years. The diverging results that exist between studies highlight the complexity of this topic.

Maternal Dietary Patterns and Birth Outcomes: A Systematic Review and Meta-Analysis

Findings on the relations of maternal dietary patterns during pregnancy and risk of preterm birth and offspring birth size remain inconclusive. We aimed to systematically review and quantify these associations. We searched MEDLINE, Embase, CENTRAL, and CINAHL up to December 2017. Three authors independently conducted a literature search, study selection, data extraction, and quality assessment. Summary effect sizes were calculated with random effects models and studies were summarized narratively if results could not be pooled. We included 36 studies and pooled results from 25 observational studies (167,507 participants). Two common dietary patterns-"healthy" and "unhealthy"-were identified. Healthy dietary patterns-characterized by high intakes of vegetables, fruits, wholegrains, low-fat dairy, and lean protein foods-were associated with lower risk of preterm birth (OR for top compared with bottom tertile: 0.79; 95% CI: 0.68, 0.91; I2 = 32%) and a weak trend towards a lower risk of small-for-gestational-age (OR: 0.86; 95% CI: 0.73, 1.01; I2 = 34%). Only statistically data-driven healthy dietary patterns, and not dietary index-based patterns, were associated with higher birth weight (mean difference: 67 g; 95% CI: 37, 96 g; I2 = 75%). Unhealthy dietary patterns-characterized by high intakes of refined grains, processed meat, and foods high in saturated fat or sugar-were associated with lower birth weight (mean difference: -40 g; 95% CI: -61, -20 g; I2 = 0%) and a trend towards a higher risk of preterm birth (OR: 1.17; 95% CI: 0.99, 1.39; I2 = 76%). Data from observational studies indicate that greater adherence to healthy dietary patterns during pregnancy is significantly related to lower risk of preterm birth. No consistent associations with birth weight and small- or large-for-gestational-age were observed.

A Retrospective Cross-Sectional Population-Based Study on Prenatal Levels of Adherence to the Mediterranean Diet: Maternal Profile and Effects on the Newborn

The Mediterranean diet (MD) is a dietary pattern with important benefits. The objectives of this study were to assess the adherence to the MD among pregnant women in Valencia (Spain) and characterize the pregnant women according to their level of adherence. Finally, we aimed to examine the role of MD adherence during pregnancy in the anthropometric development of the newborn. The study included 492 pregnant women who were followed at La Fe Hospital in 2017. The self-administered "Kidmed" questionnaire for data collection on dietary information evaluation was used and a clinical history review of mothers and newborns was performed. Two groups of mothers were identified: those with low adherence (LA) and optimal adherence (OA). The study revealed that 40.2% of the women showed LA to the MD. The newborns born to these women presented a higher risk of being small for gestational age (SGA) {adjusted odds ratio (aOR) = 1.68; 95% confidence interval (CI) 1.02⁻5.46} when adjusting for parental body mass index (BMI) and multiple gestation, but not when adjusting for all significant possible confounders (aOR = 2.32; 95% CI 0.69⁻7.78). The association between MD and SGA was not significantly affected by the use of iron and folic acid supplements (aOR = 2.65; 95% CI 0.66⁻10.65). The profile of the pregnant woman with LA is that of a young smoker, with a low level of education and a low daily intake of dairy products. These results suggest that LA to the MD is not associated with a higher risk of giving birth to a SGA newborn.

The effect of a lifestyle intervention on pregnancy and postpartum dietary patterns determined by factor analysis

OBJECTIVE

Optimizing maternal diet during pregnancy improves maternal and infant health. This study assessed the effect of an antenatal lifestyle intervention for women with overweight or obesity on dietary patterns during pregnancy and post partum.

METHODS

This study is a secondary analysis of a randomized controlled trial in which pregnant women (BMI ≥ 25 kg/m² ) received lifestyle advice (n = 943) or standard care (n = 924). Dietary pattern analysis was undertaken using factor analysis with comparisons between trial entry and 28 weeks, 36 weeks, and 4 months post partum.

RESULTS

The dietary pattern analysis revealed two distinct patterns: "prudent" and "Western." There was a significant difference between groups in the change over time for both patterns (P < 0.001). For the prudent score, the lifestyle group had higher scores at all times after trial entry compared with standard care, while for the Western score, the lifestyle group had a lower score at 28 weeks. The intervention effect differed based on trial entry BMI (P =  0.043) and smoking (P = 0.019), with higher prudent scores for women with obesity compared with overweight and smokers compared with nonsmokers.

CONCLUSIONS

The provision of an antenatal lifestyle intervention for women with overweight and obesity was associated with an improvement in dietary patterns that persisted post partum. This has important implications for the future consideration of optimal dietary intervention components to include in antenatal lifestyle interventions.

A comparison of pregnancy outcomes in Ghanaian women with varying dietary diversity: a prospective cohort study protocol

INTRODUCTION

Poor dietary intake during pregnancy can have negative repercussions on the mother and fetus. This study therefore aims to explore the dietary diversity (DD) of pregnant women and its associations with pregnancy outcomes among women in Northern Ghana. The main outcome variables to be measured are gestational weight gain and birth weight.

METHODS AND ANALYSIS

A prospective cohort study design will be used and 600 pregnant women in their first trimester will be systematically recruited at health facilities and followed until delivery. In three follow-up visits after recruitment, information on sociodemographic and general characteristics, physical activity (International Physical Activity Questionnaire (IPAQ) short form, dietary intake (24-hour food recall), anthropometry and pregnancy outcomes will be collected. DD will be measured three times using the minimum DD-women (MDD-W) indicator and the mean of the three values overall will be used to determine low (<5 food groups) and high (≥5 food groups) DD. Data will be analysed using SPSS. Comparisons between groups (categorical data) will be made using the χ² test for proportions, and t-tests and ANOVA will be performed on continuous variables. Regression analysis will be used to identify independent outcome predictors while controlling for possible confounding factors. The results may help to identify differences in DD between healthy and unhealthy pregnancy outcomes.

ETHICS AND DISSEMINATION

The study protocol has been approved by the ethics committee of Tehran University of Medical Sciences and the ethical review committee of the Tamale Teaching Hospital. Written informed consent will be obtained from all subjects. The results will be published in due course.

Maternal dietary patterns during pregnancy and offspring cardiometabolic health at age 6 years: The generation R study

BACKGROUND & AIMS

Maternal nutrition during pregnancy might be important in influencing offspring cardiometabolic health. However, research has focused mostly on specific nutrients or total energy, and possible effects of whole diet are unclear. We aimed to assess the associations between different dietary patterns during pregnancy and offspring cardiometabolic health among 2592 mother-child pairs from Generation R, a prospective population-based cohort study from fetal life onwards in Rotterdam, the Netherlands.

METHODS

Maternal diet was assessed in early pregnancy with a food-frequency questionnaire. We identified three a posteriori-dietary patterns, namely a 'Vegetable, fish and oil', 'Nuts, soy and high-fiber cereals' and 'Margarine, snacks and sugar'-pattern. An a priori-pattern was created based on the 'Dutch Healthy Diet Index'. Cardiometabolic health (pulse wave velocity, blood pressure, insulin, HDL-cholesterol and triglycerides) was measured at the child's age of 6 years.

RESULTS

In the crude models, the 'Vegetable, fish and oil', 'Nuts, soy and high-fiber cereals' and 'Dutch Healthy Diet Index' seemed beneficial, as higher adherence to these patterns was significantly associated with lower blood pressure and lower pulse wave velocity. After adjustment for other socio-demographic and lifestyle factors, most associations disappeared, except for lower pulse wave velocity with the 'Vegetable, fish and oil'-dietary pattern (-0.19 SD (95% CI -0.33; -0.06), highest quartile of adherence vs. lowest quartile). No associations were found between maternal dietary patterns and offspring blood lipids or insulin levels.

CONCLUSIONS

Our results suggest that there are no consistent independent associations of maternal dietary patterns with offspring cardiometabolic health at 6 years.

Dietary Patterns and Birth Weight-a Review

Being born with low birth weight (LBW) is recognized as a disadvantage due to risk of early growth retardation, fast catch up growth, infectious disease, developmental delay, and death during infancy and childhood, as well as development of obesity and non-communicable diseases (NCDs) later in life. LBW is an indicator of fetal response to a limiting intrauterine environment, which may imply developmental changes in organs and tissue. Numerous studies have explored the effect of maternal intake of various nutrients and specific food items on birth weight (BW). Taking into account that people have diets consisting of many different food items, extraction of dietary patterns has emerged as a common way to describe diets and explore the effects on health outcomes. The present article aims to review studies investigating the associations between dietary patterns derived from a posteriori analysis and BW, or being small for gestational age (SGA). A PubMed search was conducted with the Mesh terms "pregnancy" OR "fetal growth retardation" OR "fetal development" OR "infant, small for gestational age" OR "birth weight" OR "infant, birth weight, low" AND "diet" OR "food habits". Final number of articles included was seven, all which assessed diet by use of food frequency questionnaire (FFQ). Five studies explored dietary patterns using principal component analyses (PCA), while one study used cluster analyses and one study logistic regression. The studies reported between one and seven dietary patterns. Those patterns positively associated with BW were labeled "nutrient dense", "protein rich", "health conscious", and "Mediterranean". Those negatively associated with BW were labeled "Western", "processed", "vegetarian", "transitional", and "wheat products". The dietary patterns "Western" and "wheat products" were also associated with higher risk of SGA babies, whereas a "traditional" pattern in New Zealand was inversely associated with having a SGA baby. The dietary patterns associated with higher BW or lower risk of having babies born SGA were named differently, but had similar characteristics across studies, most importantly high intakes of fruits, vegetables and dairy foods. Dietary patterns associated with lower BW or higher risk for giving birth to a SGA baby were characterized by high intakes of processed and high fat meat products, sugar, confectionaries, sweets, soft drinks, and unspecified or refined grains. All studies in this review were performed in high-income countries. More research is warranted to explore such associations in low and middle income countries, where underweight babies are a major health challenge many places. Furthermore, results from studies on associations between diet and BW need to be translated into practical advice for pregnant women, especially women at high risk of giving birth to babies with LBW.

Effect of a Mediterranean diet during pregnancy on fetal growth and preterm delivery: results from a French Caribbean Mother-Child Cohort Study (TIMOUN)

BACKGROUND

Recent studies suggest that a Mediterranean dietary pattern during pregnancy may influence pregnancy outcomes. The aim of this study was to evaluate the effect of adherence to a Mediterranean diet (MD) during pregnancy on fetal growth restriction (FGR) and preterm delivery (PTD) in a French Caribbean island where the population is largely of African descent and presents dietary patterns similar to MD.

METHODS

Using data from the TIMOUN Mother-Child Cohort Study conducted in Guadeloupe (French West Indies) between 2004 and 2007, we analysed data for 728 pregnant women who delivered liveborn singletons without any major congenital malformations. Degree of adherence to MD during pregnancy was evaluated with a semi-quantitative food frequency questionnaire based on nine dietary criteria. Multiple logistic regression models were used to analyse birth outcomes while taking potential confounders into account.

RESULTS

Overall there was no association between MD adherence during pregnancy and the risk of PTD or FGR. However, pre-pregnancy body mass index was a strong effect modifier, and MD adherence was associated with a decreased risk of PTD specifically in overweight and obese women (adjusted odds ratio 0.7, 95% confidence interval 0.6, 0.9) (P heterogeneity <0.01).

CONCLUSIONS

These results suggest that Caribbean diet during pregnancy may carry some benefits of MD and may contribute to reduce the risk of PTD in overweight and obese pregnant women.

EURRECA-Evidence-based methodology for deriving micronutrient recommendations

The EURopean micronutrient RECommendations Aligned (EURRECA) Network of Excellence explored the process of setting micronutrient recommendations to address the variance in recommendations across Europe. Work centered upon the transparent assessment of nutritional requirements via a series of systematic literature reviews and meta-analyses. In addition, the necessity of assessing nutritional requirements and the policy context of setting micronutrient recommendations was investigated. Findings have been presented in a framework that covers nine activities clustered into four stages: stage one "Defining the problem" describes Activities 1 and 2: "Identifying the nutrition-related health problem" and "Defining the process"; stage two "Monitoring and evaluating" describes Activities 3 and 7: "Establishing appropriate methods," and "Nutrient intake and status of population groups"; stage three "Deriving dietary reference values" describes Activities 4, 5, and 6: "Collating sources of evidence," "Appraisal of the evidence," and "Integrating the evidence"; stage four "Using dietary reference values in policy making" describes Activities 8 and 9: "Identifying policy options," and "Evaluating policy implementation." These activities provide guidance on how to resolve various issues when deriving micronutrient requirements and address the methodological and policy decisions, which may explain the current variation in recommendations across Europe. [Supplementary materials are available for this article. Go to the publisher's online edition of Critical Reviews in Food Science and Nutrition for the following free supplemental files: Additional text, tables, and figures.].

Maternal Dietary Patterns during Third Trimester in Association with Birthweight Characteristics and Early Infant Growth

Our analysis examined the impact of maternal dietary patterns and lifestyle factors on markers of fetal growth, specifically birthweight and size for gestational age (small- (SGA) or large-for-gestational age (LGA)). The Infant Feeding Practices Study II, a prospective cohort study, surveyed pregnant women during their 3rd trimester, of which a subgroup (n = 893) completed a food frequency questionnaire. Maternal dietary patterns were evaluated by diet scores (Alternative Healthy Eating Index for Pregnancy and alternate Mediterranean diet) and by carbohydrate quality (glycemic index and glycemic load). Poisson regression with robust standard errors was used to examine the relative risk of SGA and separately LGA, with dietary patterns and other lifestyle factors. Linear regression was used to determine the association of birthweight and early infant growth with better dietary patterns. Relative risk of SGA and LGA was not associated with dietary patterns. Birthweight and infant growth were not associated with maternal diet. Smoking, however, increased the risk of delivering an SGA infant (RR = 2.92, 95% CI: 1.58-5.39), while higher prepregnancy BMI increased the risk of delivering an LGA infant (RR = 1.06, 95% CI: 1.03-1.09). Future studies are needed to evaluate whether deficiencies in more specific maternal dietary nutrients play a role in fetal growth.

Maternal dietary patterns during pregnancy and child internalising and externalising problems. The Generation R Study

BACKGROUND & AIMS

Maternal nutritional factors during pregnancy have been linked to foetal brain development and subsequent offspring behaviour. Less is known about associations between maternal dietary patterns and offspring behaviour.

METHODS

Within a population-based cohort, we assessed maternal diet using a food frequency questionnaire. Three dietary patterns were derived by means of Principal Component Analysis. Child internalising (emotionally reactive, anxious/depressed or withdrawn, having somatic complaints) and externalising problems (inattention, aggression) were assessed with the Child Behaviour Checklist at 1.5, 3 and 6 years in 3104 children. We assessed the association of maternal Mediterranean, Traditionally Dutch and Confectionary dietary pattern during pregnancy with child internalising and externalising problems.

RESULTS

After adjustment, the Mediterranean diet was negatively associated (ORper SD in Mediterranean score = 0.90, 95% CI: 0.83-0.97) and the Traditionally Dutch diet was positively associated with child externalising problems (ORper SD in Traditionally Dutch score = 1.11, 95% CI: 1.03-1.21). Neither diet was associated with internalising problems.

CONCLUSIONS

Both low adherence to the Mediterranean diet and high adherence to the Traditionally Dutch diet during pregnancy are associated with an increased risk of child externalising problems. Further research is needed to unravel the effects of nutrient interplay during and after pregnancy on child behavioural development.