Usually there is an initial rise in plasma volume followed by an increase in red blood cells. The increase in red blood cells increases your body's demand for iron. This increase in plasma can cause anemia. If you're anemic, especially during pregnancy, you may feel tired, fatigue easily or experience a general feeling of ill health. How Your Actions Affect Your Baby's Development During pregnancy, nearly every woman worries whether her baby will be perfect.
Most women worry unnecessarily.
Abnormal Fetal Development Teratology is the study of abnormal fetal development. An exact cause or reason for a birth defect is found in less than half of all cases. We believe some agents may be harmful, but researchers have not been able to prove this. However, other agents have been proved to be harmful. Some agents cause major defects if exposure occurs at a specific, critical time in fetal development.