Critical Periods of Fetal Development. Teratogens are toxic agents that can cause a birth abnormality. Developing infants are particularly at risk in the first couple of months of pregnancy during the germinal and embryonic stages as the chart shows.
TEKS (4) B - Infancy. The student analyzes the growth, development, and care of the newborn. The student is expected to:(B) explain the relationship of nurturing to the growth and development of the newborn; article: early critical periods in human brain development