Rocker Rod Stewart tells of pair's two-year IVF ordeal to be parents again

• Rod Stewart with wife Penny Lancaster. The baby is due just before she turns 40 Picture: Getty

Now veteran rocker Rod Stewart has spoken candidly about how he and his wife Penny Lancaster spent two years on IVF programmes before she fell pregnant.

The couple consulted fertility experts in the US and the UK when efforts to conceive naturally failed, describing the battle since as an "emotional rollercoaster".

• Fast-freezing gives sperm a better chance

In an interview with this week's Hello! magazine from the couple's LA mansion, the Scottish singer said: "IVF can be stressful, especially for the woman with all the hormone injections and procedures.

"When the first attempt didn't work, I said to Penny, 'don't worry, we'll just keep trying'."

Lancaster described their four-year-old son Alastair's joy on hearing he would have a sibling.

She said: "Our son's happiness made all the IVF treatments worthwhile."

Recounting the moment she was told she was finally successful, she said: "I couldn't believe it. I burst into tears. I called Rod when I was still sobbing.

"Rod said, 'I'm in the middle of a restaurant in Russia, crying'.

"I kept pinching myself. Neither of us could believe that it had finally happened."

Lancaster was told mercury levels in her body were "off the scale" as a result of her love of fish, something she believes may have contributed to their problems.

She cut seafood from her diet and after a third IVF cycle she fell pregnant.

Stewart has fathered seven children - Kimberly, 30, and Sean, 29, with first wife Alana Hamilton, and daughter Ruby in 1987 with Kelly Emberg.

He had two children - Renee, 18, and Liam, 15 - during his marriage to Rachel Hunter.

Stewart's eldest daughter, 46-year-old Sarah Streeter, was conceived when the singer was 18 and was later adopted.

She was born to Susannah Boffey, an art student with whom the singer had a year-long relationship, but who was unable to cope with the child who was put up for adoption after six months. Miss Boffey only discovered her father's identity when she was 18.

The new baby is due in mid-March, just before Lancaster turns 40 and by which point Stewart will be 66.

Photographer and model Lancaster said her husband's age was not an issue: "All the tests he's had show he's fitter than the average 45-year-old."

Stewart added: "I keep very fit and healthy and, with a young family, there's no holding me back."

Lancaster previously suggested the singer's touring schedule might be a contributing factor.

"I think touring and running around interferes with things but we're still trying and have high hopes," she said."Though once you get over 35 it takes a little longer."

Stewart said he is relaxed about being a father for an eighth time: "As a parent of a new child, I may only be around for 25 years at most.

"But it will be a happy, loving 25 years. You get children born into a family who have 25 miserable years. What's the point in that? The most important thing is I can afford it and have got the time."

Fast-freezing gives sperm a better chance

A NEW technique for rapidly freezing sperm could offer hope to couples undergoing IVF, researchers have announced.

Experts found that fast-freezing sperm preserves far more of its quality and ability to swim towards an egg than the slow-freezing method currently in use.

They hope the technique could help men with low sperm counts as well as those having their sperm frozen before undergoing cancer treatment.

The study, by experts in Chile and Germany, will be presented at the World Congress of Fertility and Sterility in Munich.

Current slow-freezing techniques have several drawbacks, and retain only about 30 per cent to 40 per cent of sperm activity, or motility.

But rapid freezing – also known as vitrification – allows that figure to rise to almost 80 per cent. Vitrification is already used to quick-freeze eggs and embryos with success.

Following thawing, more eggs and embryos survive with vitrification.

Some men with low sperm counts fail to produce a good enough sample when it is time for IVF. The new technique could also allow several samples to be put together as one.