In the first episode of the sixth series, fourth generation twins make an appearance on the delivery suite at Southmead Hospital in Bristol, a larger-than-life double act struggle to see the funny side of their extended labour, and an expectant father holds his breath hoping for a boy.

Mel is an identical twin. Her father is also a twin, as was her grandmother, so it's incredibly rare that Mel herself would be pregnant with twins, but that's exactly what has happened.

When Mel's waters break unexpectedly she has to choose whether her husband or her identical twin sister will be her birthing partner.

Larger-than-life Su felt she'd hit the jackpot when she met younger man Dan, and they arrive at Southmead in high spirits.

Their baby is in breech so they've been booked for a caesarean, but those plans are thrown out the window when baby decides to move, meaning that the couple are able to have a natural delivery.

Finally, the race is on for Katy and Rob to make it to the delivery suite before their second child arrives, and Rob is praying this one's a boy.

A muscle-mad macho man struggles to keep his nerves in check, an expectant dad goes all out to make his wife feel comfortable in the birthing room and a same-sex couple are rushed into hospital 10 weeks early.

Marion and Rachel are like any other couple in their early thirties trying to start a family, although as Rachel says, 'we can't just have an early night and make a baby,' so they shopped online for sperm.

Using Marion's eggs they based their decision on which donor had the most similar attributes to Rachel and they ended up with twins. But at their 30-week hospital scan the couple are told that one of the twins is not growing properly and they need to return to Southmeads the next day for a C-section.

Image-conscious Sarah and her husband, personal trainer Rob, arrive at the delivery suite to begin the induction process. Sarah's told she's only allowed one birthing partner and chooses her husband over her mum: a move she begins to regret as Rob shows signs of impatience.

They pass the time by discussing baby names but have very different ideas. Sarah reaches a compromise: if the baby comes before midnight, Rob gets to choose but any time after it's her decision.

Meanwhile, attentive husband Ollie and his wife Kate arrive at hospital and Ollie's armed with blankets, rugs and all the essentials to make sure Kate is as comfortable as possible. Kate wants to have a hypnobirth and Ollie is on hand to ensure everything runs to plan.

Southmead Hospital rolls out the red carpet for a celebrity 'baby': Baby Spice is coming in to support the maternity unit's charity and her arrival is causing quite a stir. Midwife Sacha in particular is giddy with excitement about meeting her idol, and brings in some treasured Spice Girl

he hospital corridors at Southmead turn blue as one young mum lets out all of her pent-up frustrations, on-off romancers finally take the plunge after 10 years of indecision, and pregnancy cravings