I heard that getting sick with a cold or flu in your sixth month of pregnancy can cause serious birth defects in the baby. Is this true?

It would be important to know what your definition of birth defects is. My definition is any baby born with a chromosomal disorder, error in metabolism, or any other anomaly not associated with either of the above. All of these types of disorders or problems occur during the first trimester. Severe flu or viral infection could cause preterm labor and all the sequela that goes with preterm neonates. Viral infections are much different than the cold or flu. Any time during the pregnancy, certain viruses can have certain deleterious effects on the fetus. You should speak to your primary care provider on specific viral infections and their effect on the fetus. Also, if you are not currently pregnant, you should have your blood tested and get any immunizations that may be needed."