Birthday is a weird and slightly perturbing play, then again considering Joe Penhall’s last show (Haunted Child), I wouldn’t expect anything less from this quirky playwright. Penhall challenges common conventions with this dark, humorous and twisted piece about childbirth, parenthood and gender.

Ed and Lisa are back in the banal maternity ward for the imminent birth of their second child. They are bored and fed up with only the view of the oppressive prison opposite to entertain them. Scarred from the complications with their first child, they are doing things differently this time round. Set on a swivelling spiral stage, the action whirls round to reveal a man in a hospital bed, nine months pregnant. This warped reverse world and reverse psychology certainly makes you think, and is so startling the audience sits upright in their seats for the full 95 minutes. Despite my distracting hayfever, I was completely engrossed in the production from start to finish.

Penhall was present in the delivery room for the birth of both his sons and it is clear from the writing that he has experienced childbirth firsthand. The writing and acting is certainly convincing – I began to wonder if male pregnancies were indeed physically possible. The action explores obvious male and female stereotyping and how the sexes are defined by their roles and duties. It is an illuminating piece illustrating perhaps how a man would and could deal with the trauma of childbirth and pregnancy and all the physical and emotional complications that come with this responsibility.

The modern clinical stage offers a stark backdrop for the play, the action is entirely set in one hospital room. The cast is made up of four talented actors, three of whom have interestingly previously taken substantial roles in TV hospital series, I particularly remember watching Louise Brealey in Casualty as a teenager. The Green Wing’s Stephen Mangan is a triumph as poor pregnant Ed, he suffers sarcasm and provides numerous laughs for the audience. His physical rendition is scarily realistic and his speech expressive, he is a pleasure to watch on stage. Lisa Dillon is a perfectly good actress though I find her a little artificial and irritating (I’ve seen her several times before), her tone of voice seems disingenuous and her manner is indifferent, she paled in comparison next to Mangan. There is some great support from Louise Brealey and Llewella Gideon as Natasha and Joyce, the overworked hospital staff. Gideon is hilariously sarky and fierce as the overly relaxed nurse, and I was thankful for Brealey’s occasional presence which offers a welcome break from the intense interchange between man and wife.

By the closing lines, I had almost got used to the idea of an impregnated man… and was certainly curious about its repercussions. Maybe one day it will be normal and Penhall’s play won’t be a study but an astonishing reality, in the meantime this is an interesting piece exploring the possibilities.

Birthday continues at the Royal Court until 4 August, book here.