Associations between maternal dietary patterns during pregnancy and early childhood development in Johannesburg, South Africa

Abstract

Background and rationale. Pregnancy presents a unique period during which the health and well-being of the offspring can be influenced. Maternal nutrition is known as an important modifiable factor for both fetal and infant growth and development. Dietary pattern analysis allows for the assessment of the diet as a whole. The use of nutrients as variables for dietary pattern analysis rather than foods or food groups are advised as it is universal in consumption and allows for easier comparison between study populations. Studies investigating the associations of maternal dietary patterns during pregnancy with fetal and infant growth and development are limited, with most studies conducted in high-income countries. The aim of this study was therefore to assess the associations of maternal dietary patterns during pregnancy with fetal and infant growth and development up to the age of 12 months in Johannesburg, South Africa. Study design and methodology. Generally, healthy women pregnant with a singleton <18 weeks’ gestation residing in the city of Johannesburg were enrolled to the Nutrition during Pregnancy and Early Development (NuPED) cohort study between March 2016 and November 2017. Data were collected as part of this prospective study at early (<18 weeks’ gestation), mid (±22 weeks) and late (±36 weeks) pregnancy, as well as birth. Offspring of the enrolled women were followed up at 6 and 12 months postpartum. Maternal habitual dietary data was collected at early pregnancy using a validated quantified food frequency questionnaire (QFFQ). A posteriori nutrient patterns were determined from 22 nutrients using exploratory factor analysis and a prior patterns using the Diet Quality Index – International (DQI-I). Ultrasound-derived fetal growth was described using 418 ultrasound scans at mid (n = 226) and late (n = 192) pregnancy in terms of biparietal diameter (BPD), head circumference (HC), femur length (FL), abdominal circumference (AC), estimated fetal weight (EFW), as well as interval fetal growth (difference between a biometric measure at two time points divided by the difference in gestational age). Infant growth and neurodevelopment were assessed at 6 and 12 months postnatal by anthropometric indices and the Protocol for Child Monitoring – Infant-Toddler (PCM-IT) version, respectively. Results. A total of 250 pregnant women were enrolled to the NuPED study. Birth data of 203 infants were available, with data of 98 mother-infant pairs available at 6 months and 100 mother-infant pairs available at 12 months postpartum. Based on the a priori dietary pattern, the study population followed a borderline low-quality diet. Three distinct nutrient patterns were identified: Pattern 1 “plant protein, iron, thiamine, and folic acid”; pattern 2 “animal protein, copper, vitamin A, and vitamin B12”; pattern 3 “fatty acids and sodium”.