By Tory Milne
BBC News Online Staff
Kristy Tenio and her husband Adam have been trying for a baby since they married seven years ago.
Kristy hopes to have children
She has been diagnosed with Polycystic Ovarian Syndrome, one of the most common causes of infertility in women - but one of the least well known. This is her story.
Kristy 27, and Adam 33, live on the west coast of the USA, where Kristy is training as a nurse.
They decided in 1996, when Kristy was just 19, that they wanted to start a family, so Kristy came off the contraceptive pill, and they waited - for two years.
In America many people have to meet the costs of medical care from their own pocket, and because she had no health insurance at the time, Kristy decided not to go to a doctor.
However, she began to put on weight - from weighing 11st 5 lb (72kg) as a teenager, she became nearly 18 stone (114kg). Kristy also started to develop excess hair growth, which upset her deeply.
Kristy at her lightest, aged 18
"I was very embarrassed. I didn't feel like a real woman.
"Women aren't supposed to wax or shave. I'm still very conscious of it".
Soon, however, her husband started work with a company that provided insurance, and Kristy took her problems to a doctor.
She explained that she had not had a period for two years, and explained her other symptoms - but her doctor told her that her weight gain was at the root of the problem, and told her to go on a diet.
It was not a success. She struggled to lose more than a few pounds, and her periods did not return.
Desperate, she tried another doctor, who finally diagnosed Polycystic Ovarian Syndrome (PCOS).
The disorder affects an estimated 5-10 percent of women of childbearing age, and is a leading cause of infertility.
Sufferers may have some or all of the following
Amenorrhea (no menstrual period)
Multiple, small cysts in the ovaries
Obesity or weight gain
Increased levels of male hormone
The doctor gave Kristy a synthetic hormone, and enough of the fertility drug clomiphene citrate for five attempts.
It failed to work for Kristy. She was forced to stop taking the drug when her body no longer reacted to the drug.
The insulin connection
Her doctor conducted more tests. Tests revealed that she also suffered from resistance to insulin - her body's tissues had stopped responding to it properly, causing the pancreas to compensate by producing too much of it.
Some scientists believe that insulin resistance may be the root cause of PCOS.
Many sufferers are advised to go on a low-carbohydrate diet to control their insulin resistance, and to help them lose weight.
Around half of PCOS sufferers are overweight, and symptoms often improve with just a small amount of weight loss.
Kristy as she is now
But after a lifetime of unsuccessful dieting, Kristy has decided to pursue a more radical option.
"I've read that many women with PCOS have had weight loss surgery and had normal healthy pregnancies afterwards. So my doctor and I think it's the thing to do.
"The only problem is that we will have to wait over a year after the operation before we can start trying for a baby again".
In the meantime, she is enjoying her nursing studies, and hopes in the future to be a children's nurse.
She is realistic about her options. She knows there is a possibility she may not ever be able to conceive.
"I'm past the disappointment stage - negative pregnancy tests don't even bother me - but my goal really is to have my own child.
Is found in 70% of sub fertile women
Is also known as Stein-Leventhal syndrome
Has no cure, but can be managed with drugs and diet
Is thought to be genetic
"I so want that experience and that bond - to carry a child. But if that doesn't happen, we'll look into adoption."
She says the knowledge that she is doing something about her situation gives her hope, but still does not detract from the deep need she feels for a child.
"It has been a roller coaster. In one way, I'm glad I haven't had kids yet, because I can just 'up and go', but there are other times when my heart just aches because I want it so much".