Food is generally the most common cause of anaphylaxis. Common food triggers include nuts, shellfish (shrimp, lobster), dairy products, egg whites, and sesame seeds.
The most common time for a scan is about 19-20 weeks of pregnancy. This is the best time to check the baby's physical development. Ultrasound scans can be done at any stage of pregnancy, with signs of pregnancy being seen as early as 5 weeks.he most common time for a scan is about 19-20 weeks of pregnancy. This is the best time to check the baby's physical development. Ultrasound scans can be done at any stage of pregnancy, with signs of pregnancy being seen as early as 5 weeks.
If ultrasound is performed in the first trimester, it can indicate fetal age within a range of 3  5 days. Later in pregnancy, it is less accurate. Up to 20 weeks, the margin of error is 7  10 days. By the third trimester, an ultrasound date can be off by as much as 3 weeks in either direction. Therefore, a baby that appears term (40 weeks) may be anywhere from 37  43 weeks.