Effects of Micronutrient levels on the maternal mitochondrial DNA copy number (mtDNA-CN) in apparently healthy term pregnant women (≥37 weeks) and in turn its effect on birth weight of the baby-A Mixed Methods Research Study.

Abstract

Background: Nutrient intake is important to the well-being of pregnant women and the fetus. Micronutrients are necessary for normal growth and development of the fetus and deficiencies have been found to be associated with intrauterine growth retardation and small for gestational age infants. The nutritive composition of a diet has important influence on mitochondrial health—nutrients provide the substrates to harvest energy in the form of adenosine triphosphate (ATP) to affect key cellular functions and processes. Micronutrients were known to stabilise the mitochondrial DNA which could be related to Birth weight. Hence this study was taken up with following objectives. Objectives: a. Quantitative study: 1. To estimate the micro nutrient levels such as serum Ferritin, vitamin B12, Vitamin A, Vitamin D, Calcium, Selenium and Zinc in apparently healthy term pregnant women(≥37 weeks) and to study the causes for nutritional anemia in this area. 2. To estimate the maternal mitochondrial DNA copy number in term pregnant women using Q-PCR technique. 3. To study the correlation between the different micronutrient levels with Dietary diversity and maternal mitochondrial DNA copy number among them. 4. To study the effects of different micronutrient levels and maternal mitochondrial DNA copy number on the birth weight of the baby.b. Qualitative study: 1. To explore the cultural beliefs and practices related to diet and nutrition in pregnancy through focus group discussions among term pregnant women, Care givers like mothers and mother-in laws . Methods: After obtaining ethical clearance, present study was conducted in 150 apparently normal term (>37 completed weeks) pregnant women at tertiary care centre. Informed consent was obtained. Data was collected using the pre-designed questionnaire. Collected 5ml of venous blood under aseptic precaution and they were stored in Central Research Lab at -20 Degree. After serum separation, Micronutrients estimations and mitochondrial DNA copy number was done using Q-PCR technique. Complete Blood Count(Using Penta ES 60 cell counter) Serum ferritin, serum Vitamin B12 and Vitamin D (SNIBE Maglumi 1000 autoanalyser, which works on the principle is Chemiluminucence method (CLIA). Zinc and Calcium was estimated using a Fully automated analyser BA-400 of Bio-system company. Selenium by inductive couple plasma mass spectrometry (ICP-MS). Vitamin A By chromatographic methods using HPLC method. Results: In the present study Dietary diversity, Calorie intake, protein intake, Gestational weight gain was associated with Birth weight of the baby, Dietary Diversity and protein intake was found to be statistically significant(p<0.05). There was statistically significant positive correlation between maternal serum zinc, serum calcium and serum folic acid with dietary diversity with correlation co-efficient of 0.183, 0.192 and 0.21 respectively There was a statistically significant negative correlation between Maternal mitochondrial DNA copy number and birth weight of the baby (r=-0.25, p=0.002). There was a statistically significant positivecorrelation between maternal serum micronutrients such as ferritin (r=0.17, p=0.035), Vitamin D3(r=0.21,p=0.008), Calcium (r=0.16, p=0.04), and folic acid (r=0.23, p=0.004). Serum Ferritin, Vitamin D, Selenium, Zn, Calcium, Folate levels were significantly lower in mothers of low birth weight baby when compared with normal weight baby. Antioxidant micronutrients Se, Zn, Vitamin D was negatively correlated with Mt DNA CN. There is a reduced affordability for the protective food items which are rich in micronutrients. There is a high calorie malnutrition and hidden hunger noted in our study group. Dietary diversity is an important factor which determines the adequate micronutrient intake. It should be increased by incorporating the food items rich in micronutrients in pregnancy. There was a less compliance for IFA supplementation. Conclusion: There is an association between micronutrients and Birth weight of the baby. Only improving Dietary diversity is not going to help in improving the micronutrient levels, but proper planning of menu with good representation of protective food could help. Since there is lot of prejudices in the food intake in pregnancy, nutrition education could help. Micronutrient Supplementation could have questionable benefit, since the compliance for tablet intake was very poor. Food fortification could be helpful in improving the micronutrient supplementation and good birth weight of the baby. Mitochondrial DNA copy number gave the objectivity for the present study at the molecular level, could have influenced by the micronutrients and in turn affect the birth weight of the baby