With female celebrities regularly debuting babies at age 45 and up, it can be easy to forget that getting pregnant grows increasingly more difficult with age.

A number of factors make both conception and a healthy pregnancy harder for women in their 40s. Namely, as you near perimenopause, ovulation becomes irregular, making conception more difficult.

Secondly, whereas men are constantly producing new sperm, women are born with all the eggs they’ll ever produce. By the time four decades have passed, those eggs have aged, increasing the chance of chromosomal abnormalities.

In addition, older women are at increased risk for a host of medical issues and complications throughout pregnancy, including high blood pressure and gestational diabetes.

In 2012, we interviewedMargery Gass, MD, who was then the executive director of the North American Menopause Society (NAMS) and a NAMS-certified menopause practitioner. She gave us the scoop on the pros and cons of conceiving and delivering a child as you near perimenopause.

Healthline: How much harder is it to conceive when you’re in your 40s versus a younger age?

Dr. Gass: A 30-year-old woman has a 20 percent chance of getting pregnant in any given month. At 40, that figure plummets to 5 percent. By the time you reach 45, your chance of a healthy pregnancy using your own eggs is 1 percent. That’s why women over 35 looking to conceive are encouraged to see a reproductive endocrinologist after just 6 months of trying, while younger couples are encouraged to try on their own for a full year.

Healthline: But women in their 40s can still get pregnant, correct?

Dr. Gass: Absolutely! Never assume, “Oh, I’m too old to get pregnant.” Unless you have gone a year without a period — the technical definition of menopause — pregnancy remains a possibility. Some women may experience menopausal symptoms, such as hot flashes or skipped periods for a few months, only to have them disappear and their cycle return. For birth control, you might want to try an IUD (intrauterine device) or a low-dose birth control pill, which can ease hot flashes and mood swings while preventing pregnancy. And unless you are in a committed relationship where both partners have been tested for sexually transmitted infections and HIV, always practice safe sex, even if you have entered menopause, because you can still contract a disease.

Healthline: What are some of the biggest risks to a woman who conceives at an older age?

Dr. Gass: Medically speaking, the risks go up considerably with age. Inwomen over 40, gestational diabetes is twice as common, and the risk for high blood pressure and placental problems, such as placenta previa (a condition in which the placenta covers the cervix) increases as well. A woman over 40 also experiences a 50 percent cesarian-section rate — much higher than the national average — because her uterus typically doesn’t function as efficiently to push the baby out. Older women may also be more prone to ectopic pregnancy (when an embryo implants outside of the uterus), which can be life-threatening.

Pregnancy can be harder on your body as you age. It’s more difficult to snap back into shape and lose the baby weight. This is all assuming a woman is able to maintain her pregnancy. Overall, miscarriages are quite common for women of all ages — 20 percent of pregnancies occurring among women in their 30s end in miscarriage. That’s 1 in 5, which is high. But between ages 40 and 44, it shoots to 33 percent, or 1 in 3. And at age 45, it’s 50 percent.

Healthline: How about risks to the baby?

Dr. Gass: Babies conceived by older mothers are at a much greater risk for Down syndrome: At age 40, the risk is 1 in 100, which is 10 times higher than the risk of a 25-year-old (1 in 1250). By age 49, the risk is 1 in 10. Factor in other birth defects or chromosomal abnormalities and the risk increases even more. That’s why many older women use donor eggs — you assume the risk of the (almost always younger) donor. Many of the older celebrities you see having babies are likely using donor eggs. Regardless of your age, it’s important to discuss genetic testing with your OB-GYN. Babies born to more mature women are also at greater risk for prematurity and stillbirth.

Healthline: Are there any advantages to having a baby later in life?

Dr. Gass: Well, your psychological health matters, and many older women feel more comfortable in their own skin. You have likely spent the past decade or so highly engaged in your career and finally feel ready to raise a child — and feeling ready is important. Having the financial means to raise a child is another factor, and many older women have been able to save up a sizable nest egg.

Healthline: What are some steps older women can take to ensure the healthiest pregnancy possible?

Dr. Gass: Proper prenatal care is essential. I strongly encourage getting to a normal weight before attempting to conceive, which can reduce the already heightened risk of diabetes and elevated blood pressure. Eating organic foods and practicing stress management may be helpful — but they would probably help most of us, mothers-to-be or not.