You may experience some of following changes during the second trimester, according to the National Women's Health Information Center:
Pain in your abdomen, groin and thighs
Backache
Shortness of breath
Skin changes, including stretch marks
Tingling in your hands and fingers
Itching on your abdomen, palms and soles of your feet; call your doctor if the itching is accompanied by nausea, vomiting, loss of appetite or jaundice
�
During this trimester, the weight of your growing baby will multiply more than seven times—and you will start showing more.
Screening is usually performed by taking a sample of the mother's blood between the 15th and 20th weeks of pregnancy (16th to 18th is ideal).