Maternal stress has been linked to imperfections in the fetal neuronal system leading to problems in perception, memory and lowered IQ. Major stress during 24-28th week of gestation, can be linked to autism, was reported by Dr. David Beversdorf of OSU Medical Center in the Society of Neuroscience meeting.
Some research indicates that women in lower socioeconomic groups and those with pessimistic personalities are more prone to stress and therefore to preterm labor and pregnancy complications.
Depressed and stressed out mothers should be urged to seek help. They can reduce stress by developing healthy habits, like eating a balanced diet, getting regular exercise and plenty of sleep. Finding healthy outlets to relieve stress and anxiety like getting out for fresh air, a shower before bed, or just taking a walk may be refreshing. Reducing work load if possible , both at home and at work may be helpful. Talking to ones partner, just sharing thoughts and feelings, can resolve issues and definitely decrease stress.
I believe that stress is increased during pregnancy and realizing that fact is important. Professional help is very useful in times of stress. Both psychotherapy (talk therapy) and pharmacotherapy (medications) can help resolve issues and put the mother on the path of a happy and healthy pregnancy.