The development of the fetus is highly regulated.
The 3 layered cell, gastrula will then begin to form tissues.
In the first 3 months organs will then begin to form.
All organs and body features are developed by the end of the 6th month.
The final 3 months allow for organ and feature development.
The embryo and fetus may encounter risks from the mother's exposure to environmental factors: diet, alcohol, tobacco, drugs, toxins, or infection.
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