Is secondhand marijuana smoke extremely bad for pregnant women to be around? What are the causes of secondhand marijuana smoke around newborn babies?

In a way, yes. Some of the toxins inhaled from the smoke will enter your blood and travel through the umbilical cord to baby.It is well documented that the newborn affected by marijuana smoke will have a smaller skull volume & the question of related learning problems has conflicting findings.Your best approach to any such exposure is to avoid them at any stage of pregnancy.
No. No its fine. There's not too much data on it but pregnant women smoke weed all the time. We don't see that population having birth issues/defects. It's fine. Just don't smoke while pregnant to be safe.