On the topic of fertility levels in the 30’s.
My dad was born in 31, my aunt in 36. Because of the economy my grandparents lived apart for many of these years. My grandfather got the only job he could get – auditing the public works projects fro the government… so he was on the road – mostly out west. My grandmother moved to her parents town (PA) and saw him maybe 2 times a year.

I have my grandmother’s diaries from this timeframe. Very enlightening.

My grandmother had a pregnancy scare after one of the visits. This was after my dad was born, before my aunt was born. Lets just say she considered all options (at least emotionally, as written in her diary). Fortunately, it turned out to be a false alarm. They could *not* afford a second child.

The depression definitely impacted fertility – if couples are apart due to work (or lack thereof) it’s harder to make babies.