Did extreme emotional stress during pregnancy cause birth defects or autism in the baby?

Stress. Streas has not truly been shown to be associated with any pregnancy issues. How stress affects the pregnant mothers sleep & eating patterns might effect fetal growth, but otherwise should not contribute to birth defects or autism.
Not likely. No particular cause has been associated with autism but a combination of factors may contribute. Severe emotional stress during pregnancy however may result in factors that may contribute to poor maternal health with resultant low birth and prematurity. These in turn may contribute to factors that may negatively impact a baby cognitively.
No, but a new study. Shows it's associated with an increased risk of your child's being bullied at school, oddly enough. Any thing that harmfully impacts your ability to bond with your baby or causes you post-partum depression can impact your baby's development & social interaction.

Related Questions

Are some antiepileptic medications known to cause birth defects or autism in a 22 week pregnancy?

Antiepileptic. Yes, this is something you need to discuss with your ob. Monitoring can be done, to help determine if there are any anomalies. Do not just stop the medication though, because seizures can cause a bigger problem for the fetus.

10 wks pregnant. Just got a flu. Will it harm the baby? Read about autism, birth defects? What can I do at this point? Please help! Stressed out!!

There is. 0.0000000% chance you have harmed your baby! Stop reading about autism and birth defects! OK... first off, congratulations! The best thing you can do for your pregnancy is take a prenatal vitamin. Don't smoke. Avoid alcohol. Limit or eliminate caffeine. But beyond that, just take care of yourself. Pregnancy is a natural process and a wonderful journey. Enjoy it and relax!
Things to ponder. You can do nothing at this point other than try to maintain a healthy diet, get proper rest & prepare for the work ahead. Every pregnancy has a 4% risk of some unexpected outcome, including all forms of birth defects, prematurity, infection, etc. Emerging data on autism suggest a curious change in genetic information present at conception, not induced by flu or other agents later.