Factors influencing fetal growth

Area of Science:

• Reproductive biology
• Developmental biology
• Endocrinology

Background:

• Fetal growth is exponential, with 95% of weight gained in the last 20 weeks of gestation.
• Multiple factors influence fetal growth, including genetic, nutritional, environmental, uteroplacental, and fetal elements.
• Key determinants include uteroplacental/umbilical blood flow, transplacental glucose, and fetal insulin.

Purpose of the Study:

• To investigate the roles of fetal pituitary (growth hormone) and thyroid in fetal growth.
• To explore the influence of placental lactogen, somatomedin, or somatostatin-like substances on fetal growth.
• To identify potential placental-fetal growth-promoting and growth-regulating factors in humans.

Main Methods:

• Review of existing literature on factors affecting fetal growth.
• Analysis of data from studies on anencephalic or athyroid fetuses.
• Extrapolation from experimental findings in animal models (e.g., rats).

Main Results:

• The roles of fetal pituitary and thyroid hormones in fetal growth are not fully understood.
• Anencephalic or athyroid fetuses typically show minimal or no growth retardation.
• Evidence from rat studies suggests the existence of specific placental-fetal growth factors.

Conclusions:

• Further research is needed to elucidate the precise roles of fetal endocrine organs in growth.
• The existence of specific placental-fetal growth factors in humans is hypothesized.
• Identification of these factors could significantly advance the prevention, diagnosis, and treatment of fetal growth retardation.