It has not quite got to the stage where players will be issued with feeding bottles as well as water bottles, but the tennis family is about to welcome more babies into the fold. Roger Federer, a new father of twins, returns to the tournament circuit in Montreal next week, while Kim Clijsters, with her daughter Jada in tow, makes her long-awaited comeback in Cincinnati.
The patter of tiny feet is not an uncommon sound in players' lounges across the world, but in the vast majority of cases they are the children of tennis-playing fathers rather than mothers. While not many fathers win Grand Slam titles – just eight have done so since 1980, with only Jimmy Connors winning more than one – no mother has triumphed since Evonne Goolagong won Wimbledon in 1980, three years after the birth of her first child. The previous mother to win at the All England Club was Dorothea Lambert Chambers in 1914.
Given the parlous state of women's tennis, there are many who predict a highly successful comeback for 26-year-old Clijsters, but history is hardly on her side. Austria's Sybille Bammer, the world No 29, is the only mother in the current top 100 and is one of just eight women since Goolagong who have returned to the main tour after having children.
Most made little impact. Laura Gildemeister won a title in 1989, Rosanna de los Rios reached two tour semi-finals in 2001 and Lindsay Davenport won three tournaments and climbed back into the world's top 25 after her brief return at the end of 2007. The American, who was back on the court barely a month after becoming a mother, gave birth to her second child six weeks ago.
While Federer insists that fatherhood will have no major impact on his career – the world No 1 plans to travel on the circuit with his family – Clijsters will leave any long-term decisions until she completes her three-tournament comeback at the US Open. Her travelling entourage includes her 17-month-old daughter, her husband, her coach, a physical trainer, an osteopath, a media representative and the occasional nanny and friend.
"I'll see how the whole trip went and which things I have to adjust," she said. "It's a new experience for me. I'm travelling with a family. Being back on tour is going to be completely different."
Almost all mothers who return to professional sporting careers agree that practical problems, such as child-care issues, are the biggest to overcome: playing sport is the easy part compared with ensuring the health and happiness of your family.
"There's absolutely no physical reason why players shouldn't come back after having babies," said Dr Anik Shawdon, who has worked as a doctor at the Australian Open. "After pregnancy a woman should be just as strong as she was before, if not stronger. Some women can put on quite a lot of weight during pregnancy, which might mean they will take a little longer to get back into shape, but if you maintain an exercise regime you should be able to come back pretty quickly.
"Many sportswomen actually find that they are mentally stronger when they return. The discipline that you have to follow when you have a baby, particularly if you're breast-feeding, should help you with the discipline you need in your training programme."
Distance runners have been particularly successful. Liz McColgan enjoyed a long and successful marathon career after becoming a mother, while Paula Radcliffe won the New York Marathon only nine months after giving birth. The Scottish golfer Catriona Matthew won the British Open last weekend less than three months after giving birth to her second child.
Davenport's example showed Clijsters what was possible. "Lindsay and I have always kept in touch," she said. "A lot of it was just talking about how the kids were doing, sending pictures of the babies back and forth. We didn't really talk much about life on tour as a mother and as a wife."
Clijsters will be welcomed back into tennis with open arms. Her retirement was a setback for the women's game, particularly as Justine Henin and Martina Hingis quickly followed her off the stage. Her sunny disposition and bold game won both admirers and titles before she quit in May 2007. Although she had only the 2005 US Open to show for her five appearances in Grand Slam finals, the Belgian won 34 singles titles and nearly $15m (some £9m) in prize-money. She was the world No 1 for 19 weeks.
Her commitment to tennis seemed to wane after she struggled with injury problems. She announced her engagement three years ago to Brian Lynch, an American basketball player, married in the summer of 2007 and gave birth to Jada Ellie in February 2008.
The All England Club played a major part in her decision to return. Clijsters played alongside Andre Agassi, Steffi Graf and Tim Henman in an event to test Wimbledon's new Centre Court roof earlier this summer and so enjoyed getting back into shape that she decided to make a trial return to competition. She has accepted wild cards into tournaments in Cincinnati and Toronto as well as the US Open.
Clijsters, who breastfed for nine months and hardly played for two years, said: "When I started playing tennis again my strokes were there very quickly, but physically it was harder. In my mind I know how I wanted to move, when I had to run forward or when I had to take a step backwards, but my mind and body weren't really connecting the same way.
"I really had to tell myself that I had to start from zero and take it one step at a time and try not to look too far ahead, try not to look at negative things. Now, luckily, it feels like it never happened. Now I feel like I'm back in good shape."
Clijsters said the most difficult part was rebuilding her serve. "The timing has to be perfect – bending your legs, rotating your hips, your shoulders, hitting the ball at the right moment," she said. "Everything has to be so correct and precise."
Serena Williams is among those who are predicting a successful comeback. "She was always a strong player and always a fighter," the Wimbledon champion said. "I think she will eventually be able to reach the level she was at before she retired – and probably be even better."
Paula Radcliffe: 'You need a supportive partner – and a baby that sleeps well'
Paula Radcliffe felt physically stronger after the birth of her daughter, Isla, two years ago but believes that mental strength was just as important a factor in her winning return to distance running. "Because you have your child you feel happier and I think that transfers into your sport," she said. "I don't know whether it's a process of the pregnancy or of giving birth, but you just feel things are more in perspective. When you go through a difficult phase in your sporting life they're easier to get through.
"Before you have a baby it's hard to stop thinking about your sport the whole day long, even when you're not competing or training. Whether I come back from a good training session or a bad training session, Isla doesn't care. She's just glad that mummy's come home. Having her around definitely normalises things."
She added: "I love my running, but I also wanted to have a child. If I had just carried on doing my sport until I finished, and then had a child, I think I would have come to resent my sport for taking something away from me that I wanted."
Radcliffe, 35, agrees that organising child care is the trickiest part of combining motherhood with a sporting career. She says she could not do it without the support of her husband, Gary, and their parents.
"I do find that I need to concentrate on my sport," she said. "I've never found it great to be at training and have Isla there. It's a distraction. If you're in the weights room you worry whether she's going to pull something over. If you're on the track you're going to worry whether she's going to disturb other people who are training or distract me if she's crying. Even if someone else is there looking after her I don't want to hear her crying. I want to be focusing on my training."
Nevertheless, Isla travels almost everywhere with her parents. "We didn't have her for any sporting reason, to improve my performances or whatever, so we wanted to have her with us all the time," Radcliffe said. "She was also a very good traveller and a good sleeper, so it wasn't stressful. To be honest, it would have been harder for me to leave her behind and worry about her than to have her with us, so we took the decision that it would be better, for example, to bring grandma along with us and have her there with us at races."
Radcliffe thinks travelling would be the biggest problem for a tennis-playing mother. "You'd have to have a very supportive partner and probably a nanny to travel with you as well," she said. "You also need a baby who travels and sleeps well, though I think that sometimes it's a question of what they're used to."
Sybille Bammer: 'I was so much stronger mentally when I came back – I knew it was my last chance'
Sybille Bammer makes a decent living out of tennis – she has already earned $255,910 (about £150,000) this year – but being the only mother in the world's top 100 does entail extra costs. Her eight-year-old daughter, Tina has had her own mobile phone since Easter. "We speak every day that I'm away," Bammer said. "She calls me a lot."
Until Tina started going to school she was a regular on the tennis circuit. "We travelled as a family to almost every tournament," 29-year-old Bammer said. "It wasn't too difficult. We were well-organised. Everyone helped, particularly my coach and my boyfriend. Tina was a very good sleeper. She was very good at night. Travelling was the worst part. She hated having a seat belt on, either on a plane or in a car.
"When I first became pregnant I wasn't sure if I would continue playing, but my boyfriend said I was still very young and he wanted me to continue. He said he was happy to quit his job for a while and look after the baby. He only started working again after Tina started school."
Bammer had made little impact before becoming a mother but won her first tournament back – an International Tennis Federation event in Grenoble – just six months after giving birth. Subsequently she made steady progress, breaking into the world's top 100 four years ago and reaching a career-high No 19 in the world rankings at the end of 2007. She won her second title on the main tour in Prague last month.
"I'm proud because before I had my daughter my best ranking was 200," she said. "I think I was so much stronger mentally when I came back. I really knew this would be my last chance. I knew that if I wasn't successful this time I would have to give up tennis. I think it would be easier to come back if you've already been a successful player, rather than try to come back and reach the top for the first time."
Bammer thinks she will find touring tougher than her daughter in the years ahead. "At home she has a lot of friends," she said. "Her father is there and she also has both sets of grandparents around. I think she understands better now why I'm away a lot, though it's not always easy for her.
"Most kids grow up with their mother with them all the time, while their father goes out to work. Tina has friends whose parents both go out to work, but she knows that they leave in the morning and come back home every day, whereas I have to be away at tournaments."
Bammer thinks Clijsters will enjoy "an unbelievably good comeback" and does not rule out the Belgian becoming world No 1 again. "She's making very good preparations for her return and I think she will be very strong," she said.
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