A Summary of Pathways or Mechanisms Linking Preconception Maternal Nutrition with Birth Outcomes

Abstract

Population, human, animal, tissue, and molecular studies show collectively and consistently that maternal nutrition in the pre- or periconception period influences fetal growth and development, which subsequently affects the individual's long-term health. It is known that nutrition during pregnancy is an important determinant of the offspring's growth and health. However, now there is evidence that the mother's nutritional status at conception also influences pregnancy outcome and long-term health. For example, the mother's nutritional status at conception influences the way energy is partitioned between maternal and fetal needs. Furthermore, placental development during the first weeks of gestation reflects maternal nutrition and establishes mechanisms for balancing maternal and fetal nutritional needs. Also, maternal nutritional signals at fertilization influence epigenetic remodeling of fetal genes. These findings all indicate that maternal parenting begins before conception. The following papers from a symposium on preconception nutrition presented at the 2015 Scientific Sessions and Annual Meeting of the ASN emphasize the importance of maternal nutrition at conception on the growth and long-term health of the child.

Keywords: birth weight; gestational age; nutrition; preconception; pregnancy.

FIGURE 1

An energy supplement during pregnancy affects infant and maternal outcomes differently in women experiencing current (A and B) or long-term (C and D) nutritional deficits. Women in the lowest quartile of skinfold thickness (A), an indicator of current nutritional status, have a greater increase in birth weight than those in the highest quartile when exposed to a higher amount of an energy supplement. An opposite relation is shown for maternal weight gain (B), suggesting that the supplemental energy is used for fetal growth at the expense of maternal gain. Knee breadth, which is determined by bone growth early in the mother’s life, is an indicator of long-term maternal nutrition. A high intake of supplemental energy had a small effect on birth weight in mothers in the lowest quartile for knee breadth (C) who gained less weight (D), suggesting that mothers with long-term undernutrition are less responsive to energy supplementation during pregnancy. This was exploratory work, so the authors used P < 0.20 as the criterion for significance in analysis of these 2-way interactions. All differences in each panel meet this criterion for statistical significance. Adapted from reference with permission.

FIGURE 2

Placental nutrient sensing. The placenta integrates maternal and fetal nutritional signals with information from intrinsic nutrient sensors, such as mTOR signaling. This process balances fetal demand with the ability of the mother to support pregnancy. Thus, the placenta plays a critical role in sensing the mother’s nutrition at conception and throughout pregnancy, and then modulates resource allocation. IGF, insulin-like growth factor; mTOR, mammalian target of rapamycin; PTHrp, parathyroid hormone–related peptide. Reproduced from reference with permission.

FIGURE 3

Conceptual framework of stages of pregnancy potentially affected by nutrients. Various aspects of maternal underlying nutrition and nutritional interventions influence the growth and development of girls and their future pregnancy outcomes. LBW, low birth weight. Reproduced from reference with permission.