Women should take a "baby break" from their careers in their late twenties to avoid the potential trauma of not being able to have children in their mid-to-late thirties, a report says today.

The theory that working women are leaving it too late to have children follows a survey showing that more than a third of women - average age 29 - who were deferring pregnancy were doing so because they were saving for a house, while a fifth wanted to establish their career.

Susan Hart, editor of Pregnancy & Birth magazine, which commissioned the poll of 2,000 women, said career opportunities could be recaptured but women should not waste fertility opportunities.

"By the age of 35 women are half as fertile as they were at 25 and by 40 women are half as fertile as they were at 35. We are not suggesting women start having babies the minute they are one step up the career ladder but that they think seriously about finding Mr Right and taking a career baby break by their late twenties."

Two thirds of couples who fail to conceive think their past lifestyle has contributed to their fertility problems.

But the most common causes of problems are not ovulating (39 per cent of women), polycystic ovary syndrome (20 per cent), blocked fallopian tubes (18 per cent) and low sperm count (19 per cent of men).

An estimated one in seven couples have fertility problems.

The average couple who failed to conceive said their GP only acknowledged their fertility problem after 17 months of trying for a baby.

　　英国的一份研究报告提醒说，妇女应该在30岁之前做妈妈，以避免在35岁以后可能无法怀孕的痛苦。

　　据英国9月1日《每日电讯报》刊登英国杂志《怀孕和生育》的一份研究报告说，对该国2000名妇女所做的调查表明，在那些平均年龄为29岁的职业女性中，三分之一为了省钱买房的人、五分之一为事业而奋斗的人选择暂时不要孩子。

　　报告指出，职业机会可以再次获得，但女性朋友不应该浪费生育能力的黄金时期。《怀孕和生育》杂志编辑、这项研究的负责人哈特称：“女性35岁时受孕能力为25岁时的一半，而40岁时又是35岁时的一半。我们并不是建议那些在事业刚刚起步的女性匆忙要小孩，只是她们应该认真考虑找到自己的真命天子，并在30岁之前做妈妈。”

　　报告说，三分之二的不孕夫妇认为不孕和他们过去的生活方式有关。而最主要的不孕原因是不排卵（39％的女性）、多囊卵巢综合征（20％）、输卵管阻塞（18％）和精子数目低（19％的男性）。

　　报告估计，大约七分之一的夫妇存在生育问题。普通不孕夫妇表示，他们是在试图怀孕17个月后才发现存在生育问题。