When I was on a research hunt in Lowndes County, Alabama a few months ago, I went to the Archives in Montgomery, Al. While searching for other information I ran into microfilm with REGISTER OF BIRTHS. I started searching through it and came upon family members births between 1910-1915. I found people that were born that were never mentioned or on census records and the ones who they said were born and died who no one remembered their names. This is a gold mine of information for us. I don't know if all states have them but it is worth checking out.
They have questions on the form like this:
NAME OF CHILD DATE OF BIRTH MONTH DAY YEAR A.M P.M PLACE OF BIRTH COUNTY CITY OR TOWN STREET AND NO. WHITE BLACK MALE FEMALE LIVE [BIRTH] STILL SINGLE TWINS TRIPLETS PRESENTATION [TYPE OF BIRTH] HEAD BREECH CROSS LEGITIMATE ILLEGITIMATE DURATION OF LABOR FULL NAME OF MOTHER AGE COLOR BIRTHPLACE OF MOTHER OCCUPATION OF MOTHER NO. OF CHILD OF MOTHER NO. OF CHILDREN OF MOTHER NOW LIVING NUMBER MARRIAGE OF MOTHER FULL NAME OF FATHER AGE COLOR BIRTHPLACE STATE OR COUNTRY OCCUPATION OF FATHER NO. OF CHILD NO. NOW LIVING NO. OF MARRIAGES REPORTER'S NAME REMARKS
It is on a long form. Try and find this REGISTER OF BIRTHS for your State and County. The information if very useful.