Richard Molloy’s new comedy-drama about the trials and tribulations of conceiving presents two middle-class couples at different life stages - the nesting thirty-somethings, versus the fortysomething empty-nesters.

Energetically directed by Alice Hamilton, the play raises questions about the materialism of fertility and what success means in terms of coupledom.

The script is laugh-out-loud funny with marked tonal shifts as the writing swings between farce and tough realism.

Ham & High: Jemima Rooper, Sandro Rosta and Bally Gill in The Harmony SydromeJemima Rooper, Sandro Rosta and Bally Gill in The Harmony Sydrome (Image: Richard Lakos)

The issue of double standards is flagged in the opening scene as naïve, out- of-work actor Kash [Bally Gill] and his bossy schoolteacher wife Zoe [Pearl Chanda] discuss their fertility programme.

Zoe repeatedly stresses ‘the language we use is important’ so he must not say timetable but fertility plan.

Zoe has also written a checklist of baby items: expensive pram and cots, breast pumps, vitamins. When Kash brings home an exclusive fertility drug flogged by a conman moonlighting as a sales assistant at a health store, his absurd revelation that it’s a remnant of Jesus’ foreskin doesn’t deter her for long.

Meanwhile, best friend Naomi [Jemima Rooper] declares to husband Charlie [Milo Twomey] that she can’t bear him. She goes to the gym once and hooks up with an absurdly ripped personal trainer Rocco, [Sandro Rosta], who is half her age.

Naomi moves into Zoe and Kash’s pad – a brilliantly detailed Ikea kitchen-sink set - to launch her affair. Farcical situations are mined as Rocco ambles repeatedly into explosive domestic scenarios.

Molloy does not go easy on male vanity. Kash is a man-boy who whinges readily, especially when Rocco borrows his boxers to fetch a glass of water following another bout of loud sex.

Charlie’s drunken diatribe about male lust, fidelity and sacrifice is a highpoint: the bathos is perfectly pitched.

Ham & High: Sandro Rosta as Rocco and Milo Twomey as Charlie in The Harmony SyndromeSandro Rosta as Rocco and Milo Twomey as Charlie in The Harmony Syndrome (Image: Richard Lakos)

The performances are very strong, 'though whether Kash and Zoe are a credible couple is debatable. With the results of their harmony blood test and the viability of a successful pregnancy hanging over them, the tone shifts into kitchen-sink gloom and the plotting feels somewhat schematic.

But the searing pain bound up with the difficulty of conceiving is conveyed with heart and force.

Beneath the acidic exchanges, the desperation to have a family is honoured.

The Harmony Test runs at Hampstead Theatre until June 22.