Five pairs of teenage girls facing similar and potentially life-changing decisions are followed as The Adult Season opens with the documentary series My Big Decision.

The first episode follows two teenage girls who are determined to have a baby.

Separated by age, culture and geography, but sharing the same all-consuming desire, the girls go on a very personal journey of self discovery – but they’re taking their mums and grans with them.

Taking a break from everyday life, the six women embark on a five-day road trip across the UK, immersing themselves in the subject matter. Offering help and support throughout the experience, it’s the last chance the older women have to persuade the teenagers to really think about making the right choice.

Sixteen-year-old Chantelle lost her virginity at 13. Having been with her boyfriend for a year and a half, she is desperate for a child. Her mum, Mandy, and 81-year-old gran, Maggie, are very much against the idea. Why does Chantelle so desperately want a child?

Headstrong only child Lydia is convinced that she’s independent enough to raise a child, even though she’s only 14 years old and doesn’t have a boyfriend. Mum, Josephine, and family friend Lynn cannot understand why she wants to throw her teenage years away.

Along the way, the families are introduced to people and situations that are designed to get them talking openly and honestly and to help inform their decision.

Both girls spend the day exploring how their futures could pan out in a career day. Chantelle, who wants to be a hairdresser, spends the day assisting a top stylist on a fashion shoot, while Lydia, who loves to cook, spends the afternoon in the kitchen of a posh restaurant.

Both families spend the day with a teen mum; visit a maternity ward; and talk openly and honestly about themselves and their relationships with each other with a psychotherapist. Then the teens are given computerised “babies” which they must look after for 24 hours.

Finally, after five days on the road, has their shared experiences had any effect on the girls’ decisions?

Thursday 16 July
9.00-10.00pm BBC THREE