A Dunedin teen mum-to-be has received a stern lecture from a judge after she was caught drink-driving midway through her pregnancy.

18-year-old Jahmayla Santana Stewart has appeared before the Dunedin District Court today, after being pulled over by police on Friday with a blood alcohol level of 250.

Her lawyer said the unemployed teen was pressured into driving because she was the least intoxicated of her group of friends.

But Judge Kevin Phillips said her drinking was almost criminal, and Foetal Alcohol Syndrome could affect or even destroy her baby's life.