What are the critical periods in prenatal development

Events of Fetal Development. A. 9 to 12 weeks. 1. Head still dominant with brain enlargement continuing and cervical and lumbar ... Fetal cells produce oxytocin, which stimulates prostaglandin production by the placenta ... B. Stages of labor. 1. Dilation stage – rhythmic contractions occur until the cervix dilates 10 cm. A) The head of the ... ................
................