Question

During which period of pregnancy do major defects in body structure occur?

1) First trimester
2) Second trimester
3) Third trimester

Answer 1

Major defects in body structure occur during the first trimester of pregnancy.

Step-by-step explanation:

During pregnancy, the major defects in body structure typically occur during the first trimester.

During this period, which lasts from conception until about 12 weeks, the internal organs and body structures of the developing baby begin to form. By the end of the first trimester, important structures like the limb buds, eyes, heart, and liver have already been formed, although they may not yet be fully functional.

It is important for pregnant individuals to be cautious during the first trimester, as exposure to toxins or anything that interferes with development can have a severe effect on the survival of the fetus.