Getting Pregnant After 35: What to Know

Fertility, or the ability to conceive and have children, changes with age. Around 1 in 8 couples have trouble getting and staying pregnant, according to the National Infertility Association. (1)

The Role of Age in Pregnancy, and Fertility Basics

Normal, age-related declines in fertility are most pronounced in women over age 35.

Before pregnancy can occur, fertilization must take place. Fertilization is when a man’s sperm joins up with a woman’s egg. However, a number of steps need to take place before the sperm and egg meet for fertilization to happen. (2)

Semen is the substance that comes out of the penis during ejaculation. It contains millions of tiny sperm cells combined with other fluids.

Most sperm won’t make it all the way from the vagina through the cervix and uterus and into the fallopian tubes, where fertilization takes place. In fact, only a single sperm will fertilize an egg.

When Sperm Reaches the Fallopian Tubes Around the Time a Woman Ovulates, Fertilization May Occur

There are two fallopian tubes. Each connects one of a woman’s two ovaries to her uterus. Once a month, one egg will leave one of a woman’s ovaries and travel into the connecting fallopian tube. This is called ovulation.

If sperm are present in the fallopian tube when ovulation occurs, fertilization can happen. Fertilization can take place anywhere from a few hours to a few days after sex. (2)

Age and Aging Are Important Fertility Factors

Pregnancy happens when a man’s sperm fertilizes a woman’s egg and the fertilized egg attaches itself successfully to the wall of the woman’s uterus, where it will continue to grow for the next nine months.

Unlike men, who will continue to make more sperm throughout their lifetime, women are born with all the eggs they will ever have. As women enter their late thirties, there’s a steep drop-off in the quantity — and quality — of remaining eggs. The risks of miscarriages and chromosomal abnormalities in the child (for instance, Down syndrome) also increase with advancing maternal age, according to a 2014 paper. (3)

That’s why the American College of Obstetricians and Gynecologists (ACOG) recommends an infertility evaluation for couples in which the woman is over 35 and has not become pregnant after six months of trying. (4)

Related: The Truth About Miscarriage, Pregnancy Loss, and Fertility

Women typically reach menopause — when the menstrual cycle stops permanently — around age 50. It’s a common misconception that women remain fertile until that time, says the American Society for Reproductive Medicine (ASRM). (5,6) Most women will lose the ability to have a successful pregnancy by their mid-forties. (5)

In fact, the ASRM estimates that by age 40, a woman has about a 5 percent chance of becoming pregnant each month she tries. (5,6,7) Around one-half (54 percent) of women over 35 will become pregnant naturally after a year of trying. (3)

Age causes a decrease in male fertility, too. The decline is less pronounced and appears to happen later in life. But some men may begin to experience age-related changes in their sperm as early as their mid-to-late forties. (5,8) These changes can cause fertility problems and issues with chromosomal or developmental abnormalities in the child, according to the ASRM. (6)

Common Factors That Can Limit Fertility

Both men and women can have fertility problems. While you can’t change your age, there are other steps couples can take to optimize fertility, even in their late thirties. Some causes of infertility can be reversed.

• Being Overweight or Obese Overweight and obesity are clearly linked to fertility problems in both men and women. (Women who are underweight may be at risk of infertility, too.) Reaching and maintaining a healthy weight through exercise and healthy eating can help to reverse many fertility problems associated with weight. (6,7,8)
• Smoking Men who smoke are more likely to have sperm that are shaped abnormally or don’t swim properly. Women who smoke reach menopause earlier than women who don’t smoke. (5,8)
• Heavy Alcohol Consumption or Recreational Drug Use These behaviors can lead to fertility problems in both men and women. (7,8)
• Steroids Use of anabolic steroids has been linked to infertility in men. (8)
• Too Much Heat on the Genitals Some studies suggest that activities exposing a man’s genitals to excessive heat, including wearing briefs or other snug underwear, using hot tubs, or using a laptop on the lap, can raise scrotal temperature and harm sperm production. But evidence from these studies is inconclusive. (8)

Medical Factors That Can Limit Fertility

Some causes of infertility in women and men are medical. Luckily, many of these problems can be fixed with medicine or surgery.

Medical conditions that can decrease a woman’s fertility: (9,10,11)

• Ovulation Problems Most cases of female infertility can be traced to ovulation issues. Absent or irregular periods could signal issues with ovulation.
• Fallopian Tube Blockage An obstruction of one or both fallopian tubes can make it harder for a fertilized egg to get to the uterus.
• Physical Problems With the Uterus Uterine fibroids are noncancerous tumors that can develop on the walls of the uterus. While most women with uterine fibroids have no issues with fertility, fibroids can cause infertility or problems with pregnancy.
• Endometriosis The growth of uterine tissue outside the uterus, endometriosis can cause menstrual irregularities or blockages in the fallopian tubes or ovaries that can impact fertility.
• Polycystic Ovary Syndrome (PCOS) PCOS or other hormonal conditions can cause ovulation problems.

Medical conditions that can decrease fertility in men: (12)

• Testicular Problems Having an undescended testicle, a gonadal disorder, or an injury to a testicle can cause problems for testicular function and sperm production.
• Hormonal Imbalances Hormonal disorders, including hypogonadism (a condition that causes the body not to make enough testosterone) or thyroid problems, can lead to fertility problems.
• Sperm Problems Some men have problems producing enough sperm or may produce sperm that are abnormally shaped or that aren’t “good.” These sperm may have a hard time reaching and fertilizing the egg.
• Blockages Blockages in the ducts that carry sperm out of the testicles can result in fertility problems.
• Problems Ejaculating
• Varicocele This enlargement of veins in the scrotum may harm sperm production and is present in about 40 percent of men with fertility problems. (13)

How to Optimize Fertility Naturally

Getting pregnant takes time. Even for fully fertile couples in their twenties and early thirties, getting pregnant may routinely take several months. In your late thirties, you may feel you no longer have the luxury of time. Luckily, there are a few steps you can take to optimize your natural fertility and conceive as quickly as possible.

Understand Fertility and How Fertility Awareness Methods Work so You Can Strategize

• Track ovulation.
• Time sexual intercourse around ovulation.

The best way to get pregnant is to have sex every one to two days during the fertile window, says the ASRM. (5,7)

What Is the So-Called Fertile Window?

The fertile window is the five or six days of a woman’s cycle just before ovulation, when sex is most likely to result in a fertilized egg. (5,7)

Typically, a woman ovulates a single egg each month. During ovulation the egg passes from the ovary into the fallopian tube. If sperm are present in the fallopian tube, fertilization may happen. A man’s sperm can survive in a woman’s body for up to five days. (14)

Ovulation happens a couple of weeks before a woman gets her period. A woman with a 28-day cycle, for instance, might expect to ovulate on or near day 14 of her cycle, placing the fertile window between (and including) days 9 through 14. (7)

Not all women have a 28-day cycle. Normal menstrual cycle length varies between women, and some women have a menstrual cycle length that changes from month to month.

To Leverage the Fertile Window, Learn Why ‘Well-Timed Sexual Intercourse’ Is Key

Fertility awareness-based methods can help couples better understand a woman’s monthly cycle and when she’s ovulating so that they can make the most of the fertile window.

Fertility awareness-based methods for tracking ovulation include the following: (14)

• Keep a menstrual calendar.
• Take your basal body temperature each morning. A woman’s body temperature may fluctuate around 0.5 degrees F around the time of ovulation, so tracking when that change occurs can help to observe your body’s monthly pattern.
• Check the cervical mucus. As a woman get close to ovulation, her cervical mucus goes from being thick and cloudy to thinner, clearer, and more slippery.
• Use an ovulation predictor kit. These pee-on-a-stick kits detect luteinizing hormone (LH), a hormone that peaks just before ovulation.

Opt for Fertility-Friendly Vaginal Lubrication or Lube

Some vaginal lubricants have been shown to make sperm move more slowly or decrease their ability to survive inside the vagina. These include commercial, water-based lubricants, saliva, and olive oil. (15)

You may want to opt instead for a personal lubricant that’s fertility-friendly. The ASRM and Society for Reproductive Endocrinology recommend the following lubricants as safe for sperm: (15)

• Cellulose-based lubricants, including Pre-Seed and ConceivEase
• Mineral oil
• Canola oil

Be Open to a Fertility Evaluation and Treatment of Infertility

Couples struggling with age-related fertility declines or other causes of infertility may opt to get evaluated by a reproductive endocrinologist, also known as an infertility specialist.

A reproductive endocrinologist can run tests to determine the cause of infertility and recommend treatments going forward.

A reproductive endocrinologist may also assess ovarian reserve, or the number and quality of remaining eggs. But some studies, including research from 2017, have suggested that measures of ovarian reserve may not be good predictors of how likely a woman is to conceive — either naturally or with treatment. (16)