We didn't tell anyone till about 6 hours after DD was born. We had warned close friends and family that I was probably going to be induced early due to my blood pressure but didn't want anyone knowing the exact timing so they wouldn't worry or pester us if it took a long time.

Apparently my MIL rang the night I was admitted to hospital and DH just lied and said I was fine so they were surprised to hear we'd had a baby by the next evening!