Maternal Supplementation with Antioxidant Vitamins in Sheep Results in Increased Transfer to the Fetus and Improvement of Fetal Antioxidant Status and Development

Associations between maternal dietary scores during early pregnancy with placental outcomes

Background and aims

Individual macronutrient and micronutrient effects on placental growth have been widely investigated. However, the influence of overall maternal diet is relatively unknown. Therefore, the aim of this study is to examine associations between a range of maternal dietary scores during early pregnancy with placental outcomes, and to investigate whether there is evidence of sexual dimorphism.

Methods

This analysis of the Lifeways Cross-Generational Cohort includes 276 mother-child pairs. A validated 148-item semi-quantitative food frequency questionnaire assessed maternal diet in early pregnancy. Dietary scores reflecting dietary quality [Healthy Eating Index (HEI-2015), Dietary Approaches to Stop Hypertension (DASH)], dietary inflammatory potential [Dietary Inflammatory Index (DII) and the energy adjusted DII (E-DII)], dietary antioxidant status [Dietary Antioxidant Quality (DAQ)], and glycemic and insulinemic loads/indices (GL/GI, IL/II) were calculated. Linear regression analyses assessed maternal dietary score relationships with untrimmed placental weight (PW) and birth weight:placental weight (BW:PW) ratio.

Results

In fully adjusted models, maternal E-DII and GI were positively associated, and HEI-2015 and DAQ were negatively associated with PW (B: 12.31, 95% CI: 0.41, 24.20, p = 0.04, B: 4.13, 95% CI: 0.10, 8.17, p = 0.04, B: -2.70, 95% CI: -5.03, -0.35, p = 0.02 and B: -15.03, 95% CI: -28.08, -1.98, p = 0.02, for E-DII, GI, HEI-2015 and DAQ respectively). Maternal DAQ associations with BW:PW ratio were attenuated. When stratified by sex, maternal GI and pregnancy-specific DAQ were associated with PW in female offspring (B: 5.61, 95% CI: 0.27, 10.96, p = 0.04 and B: -15.31, 95% CI: -30.35, -0.27, p = 0.046). Maternal E-DII and HEI-2015 were associated with PW in males (B: 24.31, 95% CI: 5.66, 42.96, p = 0.01 and B: -3.85, 95% CI: -7.47, -0.35, p = 0.03 respectively).

Conclusion

The results of this novel investigation suggest that maternal diet may influence placental development. Female fetuses may be more sensitive to increased glucose levels whereas male fetuses may be more susceptible to in-utero stresses that are regulated by inflammatory pathways and overall diet quality. Hence, early pregnancy offers an opportune time for a mother to prioritize dietary changes that focus on reducing inflammatory and glycemic responses.

Oxidative Stress and Fetal Growth Restriction Set Up Earlier in Undernourished Sheep Twin Pregnancies: Prevention with Antioxidant and Nutritional Supplementation

Hypoxemia and oxidative stress, resulting in intrauterine growth restriction (IUGR) in undernourished twin sheep pregnancies, has been described in near-term studies. Our aim was to evaluate if the counteractive effects of maternal nutritional or antioxidant supplementation on the fetal redox status were evident before the accelerated fetal growth phase. Forty twin-bearing ewes grazing on natural Patagonian prairie were randomly assigned to four groups (n = 10 each; P: control ewes consuming mainly natural pasture; P+A: pasture plus antioxidants; P+C: pasture plus concentrate; P+A+C: pasture plus antioxidants and concentrate). Daily herbal antioxidants were supplemented in a feedstuff concentrate as a premix from day 35 until day 100 of gestation, when fetal venous cord blood samples and biometric measurements were obtained via cesarean section. The fetuses from group P were clearly hypoxemic. An analysis of variance showed that maternal antioxidant supplementation showed a trend of increased PO2, SatHb, and Ht, effects not observed in P+C fetuses. Antioxidants decreased the fetal MDA concentration (p < 0.05). Fetal TAC was increased by the antioxidants and concentrate (p < 0.05). Antioxidant supplementation showed a trend to increase fetal body weight but not biometry. The results suggest that negative effects of oxidative stress occur earlier than the overt growth arrest, and the maternal administration of antioxidants may constitute a good nutritional strategy for the early prevention of IUGR.

Molecular regulation of lung maturation in near-term fetal sheep by maternal daily vitamin C treatment in late gestation

BACKGROUND

In the fetus, the appropriate balance of prooxidants and antioxidants is essential to negate the detrimental effects of oxidative stress on lung maturation. Antioxidants improve respiratory function in postnatal life and adulthood. However, the outcomes and biological mechanisms of antioxidant action in the fetal lung are unknown.

METHODS

We investigated the effect of maternal daily vitamin C treatment (200 mg/kg, intravenously) for a month in late gestation (105-138 days gestation, term ~145 days) on molecular regulation of fetal lung maturation in sheep. Expression of genes and proteins regulating lung development was quantified in fetal lung tissue. The number of surfactant-producing cells was determined by immunohistochemistry.

RESULTS

Maternal vitamin C treatment increased fetal lung gene expression of the antioxidant enzyme SOD-1, hypoxia signaling genes (HIF-2α, HIF-3α, ADM, and EGLN-3), genes regulating sodium movement (SCNN1-A, SCNN1-B, ATP1-A1, and ATP1-B1), surfactant maturation (SFTP-B and ABCA3), and airway remodeling (ELN). There was no effect of maternal vitamin C treatment on the expression of protein markers evaluated or on the number of surfactant protein-producing cells in fetal lung tissue.

CONCLUSIONS

Maternal vitamin C treatment in the last third of pregnancy in sheep acts at the molecular level to increase the expression of genes that are important for fetal lung maturation in a healthy pregnancy.

IMPACT

Maternal daily vitamin C treatment for a month in late gestation in sheep increases the expression of gene-regulating pathways that are essential for normal fetal lung development. Following late gestation vitamin C exposure in a healthy pregnancy, an increase in lung gene but not protein expression may act as a mechanism to aid in the preparation for exposure to the air-breathing environment after birth. In the future, the availability/development of compounds with greater antioxidant properties than vitamin C or more specific targets at the site of oxidative stress in vivo may translate clinically to improve respiratory outcomes in complicated pregnancies at birth.

Maternal Supplementation with Herbal Antioxidants during Pregnancy in Swine

The effects of a combined supplementation with herbal antioxidants during pregnancy on reproductive traits and piglet performance (number of live, dead, and mummified newborns and litter weight at birth and individual body weight at both birth and weaning) were assessed in a total of 1027 sows (504 treated and 523 control females) kept under commercial breeding conditions. The supplementation increased the number of live-born piglets (13.64 ± 0.11 vs. 12.96 ± 0.13 in the controls; p = 0.001) and the total litter weight, decreasing the incidence of low-weight piglets without affecting the number of stillbirths and mummified newborns. Such an effect was modulated by the number of parity and the supplementation, with supplementation increasing significantly the number of living newborns in the first, second, sixth, and seventh parities (0.87, 1.10, 1.49, and 2.51 additional piglets, respectively; p < 0.05). The evaluation of plasma vitamin concentration and biomarkers of oxidative stress (total antioxidant capacity, TAC, and malondialdehyde concentration, MDA) performed in a subset of farrowing sows and their lighter and heavier piglets showed that plasma levels of both vitamins were significantly higher in the piglets than in their mothers (p < 0.05 for vitamin C and p < 0.005 for vitamin E), with antioxidant supplementation increasing significantly such concentrations. Concomitantly, there were no differences in maternal TAC but significantly higher values in piglets from supplemented sows (p < 0.05). On the other hand, supplementation decreased plasma MDA levels both in the sows and their piglets (p < 0.05). Finally, the piglets from supplemented mothers showed a trend for a higher weaning weight (p = 0.066) and, specifically, piglets with birth weights above 1 kg showed a 7.4% higher weaning weight (p = 0.024). Hence, the results of the present study, with high robustness and translational value by offering data from more than 1000 pregnancies under standard breeding conditions, supports that maternal supplementation with herbal antioxidants during pregnancy significantly improves reproductive efficiency, litter traits, and piglet performance.

Maternal interventions to prevent adverse fetal programming outcomes due to maternal malnutrition: Evidence in animal models

Animal studies indicate that suboptimal conditions during pregnancy adversely impact both maternal health and offspring phenotype, predisposing offspring to development of later-life diseases including obesity, diabetes, cardiovascular diseases, and behavioral and reproductive dysfunction. Effective interventions during pregnancy and/or lactation are needed to improve both maternal and offspring health. This review addresses the relationship between adverse perinatal insults and its negative impact on offspring development and presents some maternal intervention studies in animal models, such as maternal nutrition (diet modification, antioxidants, omega-3-6 (n-3-6), probiotics) or physical activity, which can prevent or alleviate negative outcomes in both mother and offspring.

Supplementation of Underfed Twin-Bearing Ewes with Herbal Vitamins C and E: Impacts on Birth Weight, Postnatal Growth, and Pre-Weaning Survival of the Lambs

Twin-bearing pregnancies of sheep reared in harsh environmental conditions result in maternal undernutrition and feto-maternal oxidative stress, leading to intrauterine growth restriction (IUGR). We assessed the efficiency of supplementation with antioxidant herbal vitamins C and E alone or in combination with concentrate throughout gestation on pregnancy outcomes, pre-weaning growth, and survival of twin lambs from grazing ewes at the Magellan Steppe. Four groups (n = 30 each) of twin-bearing ewes received a base natural prairie (P) diet, supplemented with either herbal vitamins C 500 mg and E 350 IU per day (V) or concentrated food (S); groups were: P, P + V, P + S, and P + VS. Vitamins and concentrate were supplemented until parturition. At birth, lambs were weighed, and blood was drawn for total antioxidant capacity (TAC) evaluation. Lamb body weight (BW) and survival rate were evaluated at mid-lactation (60 days) and at weaning (120 days). Vitamin supplementation resulted in increased lamb birth weight and TAC, with a trend towards higher BW at weaning, while nutritional supplementation only had a positive effect on birth weight. Lamb survival was higher in both vitamin supplemented groups. In conclusion, supplementation with herbal vitamins C and E alone or in combination with concentrate food during pregnancy may constitute a good nutritional strategy for sheep reared in harsh environmental conditions.