The period when the fetus is most likely to be deformed

Fetus is most prone to abnormal period, within 12 weeks of pregnancy, especially between 6-12 weeks of pregnancy is the stage of cell differentiation, this stage if exposed to adverse substances, even some special drugs, there is a risk of abnormal. Because this stage of cell differentiation into various tissues and organs, differentiation is completed after 12 weeks of pregnancy, and the development and growth stage of various tissues and organs begins. This stage is not teratogenic, but the possibility of teratogenicity will be greatly reduced. Deformity is slowly grown, if in pregnancy 22-24 weeks do row abnormal B ultrasound, sometimes because the fetus is too small or abnormal position, it is not easy to see abnormal organs, so 26-28 weeks to carry out the second row abnormal, this time the fetus gradually grows up, each organ exposure is also relatively clear. Therefore, general pregnancy at least two row abnormal examination, in order to rule out the fetus general deformity.