Women aged 40-42 who are having fertility problems should be offered IVF on the NHS, according to guidelines published on Wednesday by the National Institute for Health and Clinical Excellence (Nice).
Previously, Nice did not recommend IVF for women older than 39.
The guidelines also recommend IVF treatment for eligible women who have been unable to conceive after two years of regular intercourse - one year earlier than previously recommended.
They also cover women who have been having artificial insemination, which can include same-sex couples. This is the first time these have been officially included in the guidelines, which were originally drawn up in 2004.
The guidelines say women aged 40-42 who have not conceived after two years of regular unprotected intercourse or 12 cycles of artificial insemination should be offered one full cycle of IVF, if they have never previously had IVF treatment.
Where women are under 40, and have not conceived after two years of regular intercourse or 12 cycles of artificial insemination, three cycles of IVF should be offered.
Scroll down for 10 things you didn't know about fertility
Nice chief executive Sir Andrew Dillon said: "Infertility affects more people than you might think; around one in seven heterosexual couples in the UK.
"We know fertility problems can have a potentially devastating effect on people's lives, causing significant distress, depression and possibly leading to the breakdown of relationships.
"The good news is that, thanks to a number of medical advances over the years, many fertility problems can be treated effectively.
"It is because of these new advances that that we have been able to update our guideline on fertility, ensuring that the right support, care and treatment is available to those who will benefit the most."
Tim Child, consultant gynaecologist and director of the Oxford Fertility Unit, who helped develop the guideline, said: "Many women do conceive naturally in the 40-42 year age group, but for those who can't, and who have been diagnosed with the medical condition of infertility, then improvement in IVF success rates over the last decade mean that we are now able to offer cost effective treatment with a single IVF cycle.
"This decision was taken after considerable discussion and close analysis of the available evidence."
On same-sex couples, a spokeswoman for Nice said: "With the advancement of medical technology and techniques such as donor insemination, same-sex couples are now able to become parents.
"Infertility is a medical condition that can be caused by a past illness or underlying medical condition and can affect anyone, regardless of sexual orientation. Infertility can also cause real suffering and can lead to depression and the break-down of relationships.
"This is the first time same-sex couples have been included in NICE guidance on fertility. In terms of fertility treatment, same-sex couples only account for a small proportion of NHS patients - around 5%.
"However, it is important that we are sure that everyone who has this distressing medical condition has access to the best levels of help."
A full cycle of fresh IVF can cost the NHS around £3,000.
The National Infertility Awareness Campaign (NIAC) warned that as NICE guidelines are not mandatory, fears still remained over local implementation.
Chairwoman Clare Lewis-Jones said: "By updating the fertility guideline and extending the range of people it is recommending receive treatment, NICE clearly understands the impact which infertility has on people. And we must be clear that infertility is a medical condition that causes significant distress for those trying to have a baby and has a devastating impact on people's lives.
"We know infertility can be treated effectively and thousands of people have become parents after fertility treatment.
"The current 'postcode lottery' approach to the treatment of infertility here has gone on for far too long and it is vital that the Government supports the measures in the updated guideline and communicates the need to implement them to those who commission fertility services in the NHS.
"We know the current system leaves many people unable to access NHS treatment and we need reassurance about the future of NHS fertility treatment as we move towards GP commissioning in 2013.
"The new guideline gives hope to more infertility sufferers - but it is pointless if the recommendations are not put into practice. People are suffering every day because some PCTs have continually flouted the NICE guideline.
"Infertility requires specialist knowledge and GPs are, by their very definition, generalists.
"Over 50% of respondents to our patient survey last year found their GP lacked sufficient knowledge on infertility and this worries us.
"NIAC is willing and able to work with the Government to close this knowledge gap so that access to fertility treatment is improved in the new NHS."
The Royal College of Obstetricians and Gynaecologists said the new guidelines offered more choice to women trying to conceive up to the age of 42.
President Dr Tony Falconer said: "We welcome the updated guidelines and support that people experiencing fertility problems should be able to get the most appropriate and effective medical treatment and in a timely fashion."
He added: "We strongly endorse the recommendation that single embryo transfer is used if possible for women aged 39 and under. We know that replacing more than one embryo in the uterus can result in a multiple pregnancy, which carries a higher risk of complications, therefore a reduction in multiple births would have major benefits to both mother and child.
"We are aware that maternal age has risen over the years and that it is harder for older women to conceive naturally. The recommendation that IVF treatment be made available up to the age of 42 provides more choice for women but they should still be aware of the increased risks associated with pregnancy at advanced maternal age."
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<strong>1. Your fertility is mostly determined by genetics, which influences how many eggs you are born with. </strong> Doctors believe that the number of eggs you have at birth determines the length of time you will remain fertile. At birth, women have about two million eggs in their ovaries. For every egg ovulated during your reproductive life, about 1,000 eggs undergo programmed cell death. Other things, such as smoking cigarettes and certain types of chemotherapy, can accelerate egg cell death and promote an earlier menopause.
<strong>2. Regular menstrual cycles are a sign of regular ovulation.</strong> Most women have regular cycles lasting between 24 and 35 days. This is usually a sign of regular, predictable ovulation. Women who do not ovulate regularly have irregular menstrual cycles. Those who do not ovulate at all may have a genetic condition called polycystic ovarian syndrome (PCOS).
<strong>3. Basal temperature charting does not predict ovulation.</strong> An older method of tracking ovulation involves taking your oral body temperature each morning before getting out of bed. This is called basal body temperature. This method is used to spot a rise in basal temperature, which is a sign that progesterone is being produced. The main problem with using this method is that your temperature rises after ovulation has already occurred. This makes it more difficult to time intercourse at an optimal time for conception. A better method is to use over-the-counter urine ovulation predictor test kits such as Clearblue Easy. These kits test for the hormone that prompts ovulation, which is called luteinizing hormone (LH).
<strong>4. Most women with blocked fallopian tubes are completely unaware they may have had a prior pelvic infection.</strong> About 10 percent of infertility cases are due to tubal disease, either complete blockage or pelvic scarring causing tubal malfunction. One major cause of tubal disease is a prior pelvic infection from a sexually transmitted disease such as chlamydia. These infections can cause so few symptoms that you may be completely unaware your tubes are affected. This is why fertility physicians will order a dye test of the tubes, called a hysterosalpingogram (HSG), if you have been trying and failing to conceive for 6 months or longer.
<strong>5. In most cases, stress does not cause infertility.</strong> Except in rare cases of extreme physical or emotional distress, women will keep ovulating regularly. Conceiving while on vacation is likely less about relaxation than about coincidence and good timing of sex.
<strong>6. By age 44, most women are infertile, even if they are still ovulating regularly.</strong> Even with significant fertility treatment, rates of conception are very low after age 43. Most women who conceive in their mid-40's with fertility treatment are using donated eggs from younger women.
<strong>7. Having fathered a pregnancy in the past does not guarantee fertility.</strong> Sperm counts can change quite a bit with time, so never assume that a prior pregnancy guarantees fertile sperm. Obtaining a semen analysis is the only way to be sure the sperm are still healthy!
<strong>8. For the most part, diet has little or nothing to do with fertility.</strong> Despite popular press, there is little scientific data showing that a particular diet or food promotes fertility. One limited study did suggest a Mediterranean diet with olive oil, fish and legumes may help promote fertility.
<strong>9. Vitamin D may improve results of fertility treatments.</strong> A recent study from the University of Southern California suggested that women who were undergoing fertility treatments, but had low vitamin D levels, might have lower rates of conception. This vitamin is also essential during pregnancy. At Pacific Fertility Center, we recommend our patients take 2,000-4,000 IU per day.
<strong>10. Being either underweight or overweight is clearly linked with lowered levels of fertility.</strong> The evidence in recent years is that obesity is clearly linked with a longer time to conception. Having a body mass index less than 18 or over 32 is associated with problems ovulating and conceiving, as well as problems during pregnancy.