What was the main reason that the birth rate in America declined during the great depression

Parents were hesitant to have children because they couldn't afford them. Thus the birth rate went down.

During the depression, money and food and other necessities to life were running low. Parents could barely afford to keep themselves going. The fear of losing homes and jobs or even their own lives kept most adults from having children as they would be unable to afford a full family. Therefore the birth rate went down.