ABC comedy series The Letdown was one of the best Australian shows produced in recent years because it accurately depicted the mental and physical chaos those cute cherubs create.

Bump takes the chaos and amplifies it up to 11. Ambitious and Jacinda Ardern-loving year 11 student Oly (Nathalie Morris) is preparing for an exam in her inner-Sydney school when she suddenly goes into labour.

However no one, including herself, knew she was pregnant.

Oly's mother Angie is played by Australian TV royalty Claudia Karvan, who also serves as co-producer.

After the birth Angie is forced to deal with the situation while contemplating leaving her own husband, Oly's lovable but unreliable father, Dom (Angus Sampson).

When the baby's father is revealed to be someone other than Oly's studious boyfriend, it creates tension in both Oly and Angie's relationships.

Bump opens with Oly awkwardly walking in on her mum dancing in lingerie to flamenco music, while a sex toy vibrates on the floor. And from there the cheeky, yet poignantly written, comedy-drama never slackens in pace.

The birth scene in the back of an ambulance is horrifically graphic and will probably serve as a better advertisement for contraception for teens than any campaign.

Morris proves she's a talent to watch, revelling in the role as the moody tough-talking Oly, who is actually terrified and out of her depth.

"It's like the Handmaiden's Tale around here," Oly snaps at a midwife, who is encouraging her to breast feed. "Blessed is the boob."