Krista Parker, 28, had just begun planting roots for herself in the sandy soil of El Segundo, California. After years of taking assignments as a travel nurse all over the state, she accepted a permanent job in Southern California and moved into an apartment just a bike ride away from the beach. She met the man who is now her boyfriend and they developed a close group of friends who clustered at her place for game nights. The future was sunny.

What Parker didn’t know was that she suffered from polycystic ovary syndrome (PCOS). Nor did she know the extent of the link between reproductive health and lifelong wellbeing. For years, doctors weren’t sure either. Studies have since revealed strong connections that all women should know about. Breakthroughs in genetic research may create new paths to prevention, diagnostics and treatments. In the meantime, every woman can take a few easy steps to reduce her risk.

PCOS, a hormone-driven condition that interferes with eggs being released, is a common cause of infertility. But that’s not all. Women like Parker are also twice as likely to develop diabetes or dyslipidemia—abnormally high fat levels in the bloodstream—than women who don’t have PCOS. They are also more likely to be overweight, another risk factor for diabetes. What’s more, a 2011 study found that risks persist even when controlling for body weight. Those with the most severe PCOS symptoms have the highest risk. They are also twice as likely to develop endometrial cancer. 

PCOS is just one example of conditions that can lead to infertility—and future health concerns. Endometriosis, a disorder in which the tissue lining the uterus spreads beyond it—with often agonizing results—is associated with high cholesterol, heart disease and autoimmune diseases. Primary ovarian insufficiency, a condition in which the ovaries stop working normally before age 40, is linked to osteoporosis and cardiovascular disease.

"Even people who never intend to have children should pay attention to what's happening with their reproductive health," says Erica Wang, MD, a specialist in Cedars-Sinai's Fertility and Reproductive Medicine program who led the 2011 study. "It's an important window into what could happen to their bodies in the future."

Krista Parker was empowered by her diagnosis of PCOS to make a lifelong plan for her health.

Symptoms don’t have to be drastic. Parker was starting to feel “off.” Despite her happy new life, she developed mood swings. She felt like she had premenstrual syndrome, only without getting her period. Missed periods were nothing new since she used an intrauterine device (IUD) for birth control. But then her long, golden brown hair started shedding.

Based on her background as a nurse and earlier problems related to her ovaries, Parker decided to see an expert. Jessica Chan, MD, a reproductive endocrinologist at Cedars-Sinai, diagnosed her. 

“At first I was shocked,” Parker says. “I’ve always thought of myself as healthy and taken care of myself. I thought nothing could go wrong with me. Then there was all this worry that I might not be able to have kids, and I could have these other risks.”

Infertility is a fairly common health issue, with about 10% of women of reproductive age in the U.S. having difficulty becoming pregnant or staying pregnant, according to the Centers for Disease Control and Prevention. Infertility also affects about 7% of men. 

“Even in people with unexplained infertility, we see higher risks for heart disease, for example,” says Margareta Pisarska, MD, director of Reproductive Endocrinology and Fertility at Cedars-Sinai. “When women who struggled with fertility do get pregnant, they face higher risks in the short term for preeclampsia and gestational diabetes,” she adds. “They also have higher risks throughout their lives.”

In asking why, doctors first looked to fertility treatments themselves. But research published by Pisarska and her colleagues points in a different direction. 

The genetic causes of many forms of infertility are likely the culprits behind other health problems as well. 

One clue is in the placentas of women who received fertility treatments. Pisarska's team examined how the placenta forms and implants in the first 13 weeks of pregnancy and compared genetic differences between women who conceived spontaneously with those who had fertility treatments. 

They found that placentas in women who underwent in vitro fertilization had similar expressed genes to those who conceived spontaneously despite their fertility problems. In fact, the investigators discovered only one gene that differed. Meanwhile, women who had other fertility treatments—medications to increase ovulation or intrauterine insemination—had at least five genes that differed. "As a result, we think it's the infertility—not the treatments—that accounts for these differences in future health," Pisarska says. 

Hundreds of genes are associated with infertility, and Pisarska's goal is to pinpoint which ones are linked to the mechanisms causing the condition. She hopes to mine raw data from large genome studies that implicate certain genes in causing reproductive health issues. The next step would be to link the genes to what they do in individual tissues, such as the uterine lining or blood cells, to determine how these genes affect particular functions.

"We want to tailor it down to the genes' specific purposes. One might be affecting implantation of the fetus, another might affect your cholesterol and another might affect diabetes risk," Pisarska says. "If we can define these genetic profiles, we will be able to tell who is at risk of other diseases and help minimize those risks." 

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No one visits the doctor for any reason without stepping on a scale, strapping on a blood pressure cuff or having their temperature taken. For women, periods should be treated the same as other important vital signs, Wang says.

"If you don't have regular periods, you really should be on a quest to figure out why," she says. In the same way elevated blood pressure prompts discussions about lifestyle changes, medications or further testing, missing periods should inspire scrutiny. 

Missing periods means ovulation isn't happening. When the body doesn't release an egg from the ovary, it also skips making progesterone, a hormone that helps regulate the uterus lining. When that lining overgrows it can lead to endometrial cancer or a precancerous condition called endometrial hyperplasia. 

Irregular periods can have many causes but the most common is PCOS. In other cases, women aren't producing enough estrogen and their periods stop, a condition called hypothalamic amenorrhea. These women are more likely to develop osteoporosis and heart disease.

Hormonal birth control provides the estrogen and progesterone that may mitigate some of these risks. "Women will often stop a birth control pill because they were unhappy with the side effects," Wang says. "If we explain that the pill is to prevent endometrial cancer down the line, they may be willing to find an option that works for them."

Hormonal birth control can also ease the most frequent and troublesome symptoms of PCOS: irregular periods, thinning hair, hair growth on the face or body, and acne. When Parker went to see Chan, they talked about medication, among other options. "What I appreciate about Krista is that she was so proactive about seeking care," Chan says.

For mood swings, Parker decided to try lifestyle changes. After consulting with Chan and doing research of her own, she decided to eliminate dairy and gluten from her diet. "There's no ‘magic bullet' diet for PCOS," Chan says, noting that weight gain and difficulty losing weight are also common PCOS concerns. "I don't tell my patients to diet. Instead, I suggest they focus on choosing nonprocessed foods. Lowering carbohydrates can also be a good idea because insulin resistance is common with PCOS."

Being a nurse keeps Parker on her feet, but she felt she was ordering takeout or delivery meals too often and not moving much outside of work. She got back on her bike and made the most of living close to the beach, a perfect place for walks. 

Within six months, she lost weight, noticed her moods had evened out and felt better overall. "It's hard to change your diet but I've seen wonderful changes in my body and in how I feel. It's made a huge difference," she says. She follows other women with PCOS on social media and finds hope in their stories—seeing them celebrate pregnancies and the births of their children, whether conceived spontaneously or with medical help.

Parker plans to maintain her new routine and sees Chan regularly to check up on her PCOS. She jokes with her friends about what she terms her "condition," sharing openly what she's learned. Her refrigerator displays a magnet her sister gave her, proclaiming that ovaries sure can be cruel. 

She continues working as a registered nurse, mostly with patients undergoing elective surgeries. She's more strongly rooted than ever in the Southern California town that became her home three years ago. Most importantly, what Parker discovered about her reproductive health has led her to a lifelong plan to protect her heart and body.