Fertility decreases with age in both men and women. Men are still able to release active sperm well into old age. However, there is increasing evidence that sperm quality declines with age.
Women are even more at the mercy of their biological clocks. They are born with all the eggs they will ever have. Their fertility only goes down over time.
For both men and women, the ticking time clock of fertility speeds up after age 35. That’s when fertility begins to decline quickly for both sexes.
Age can and does influence the physical aspects of pregnancy. Here’s what women can expect by the decade.
Our bodies are primed to produce babies in our twenties. Physically, we’re at the top of our game. The irregular cycles of our teen years have evened out. Eggs are healthy and fresh. The body can handle the additional load on the back, bones, and muscles better than at any other time. Women in their twenties have the lowest occurrence of medical complications during pregnancy.
According to the Cleveland Clinic, the risk of miscarriage in your twenties is low—around 15 percent. There is also only a low risk of having a child with:
- Down syndrome
- spina bifida
- other chromosomal birth defects
According to the March of Dimes, at 25, your risk of having a baby with Down syndrome is one in 1,250. By 40, the odds are one in 100.
However, being pregnant in your twenties does have its hazards. According to the Mayo Clinic, the risk of pregnancy-induced hypertension (preeclampsia) is high, particularly in women over 40.
According to the March of Dimes, one in five women today waits until after age 35 to have her first child. At this age, your fertility is waning. However, your body is still capable of producing and carrying a healthy baby. You may just have to be more patient with your conception timeline. According to the American Society of Reproductive Medicine (ASRM), there is about a 20 percent chance you’ll get pregnant each month. Women in their thirties typically need three to six months longer to conceive than younger mothers do.
Women in their thirties are also at high risk for developing pregnancy-related health concerns such as:
- gestational diabetes
- high blood pressure
- placenta previa, a condition where the placenta grows near the cervix. It can cause severe bleeding during delivery
Chronic conditions, such as diabetes and high blood pressure, often become apparent in this decade. Organ and tissue damage from such conditions can complicate pregnancy.
Age 35 marks the official start of “high-risk” pregnancies. However, it’s not as if the clock ticks to your 35th year and things instantly go downhill. Instead, doctors use this age as a good indicator of when to start watching for certain problems.
At this age, your odds of having a baby with a chromosomal problem, such as Down syndrome, also increase. If you’re pregnant at 35, your baby has a:
- one in 400 chance of having Down syndrome
- one in 192 chance of having another chromosomal abnormality
The risk of miscarriage in the last half of this decade is double what it was in your twenties.
It’s not entirely uncommon for women to have babies well into their forties. In fact, between 2007 and 2009, the Centers for Disease Control and Prevention (CDC) reported that in the US, women aged 40 to 44 experienced a six percent increase in births. During the same time, all other age groups saw a decline. Still, the risks associated with advanced maternal age aren’t anything to be ignored. This is especially true as women approach their mid-to-late forties.
Fifty percent of women in their forties will experience infertility or have difficulty conceiving. According to the ASRM, women over 40 only have about a five percent chance of getting pregnant per month. This figure is true for natural conception as well as medically assisted pregnancies.
The health risks associated with being pregnant are about the same for a mother in her forties as they were for mothers in their late thirties. The difference between the two decades is in the potential effects on the baby. The chances of having a baby with a chromosomal abnormality increases dramatically. According to the March of Dimes, the risk of Down syndrome is one in 100 for a 40-year-old. It’s one in 30 for a 45-year-old. The rate of miscarriage goes up as well. The risk of losing a baby is greater than 50 percent in women aged 45 and older.
Women in their forties also have a higher chance of carrying multiple gestations as well. This is true even without medical intervention. Changes in hormone levels that occur naturally in a woman’s forties may stimulate the body to release more than one egg at ovulation.
Despite these risks, your overall risk of complications is reduced if you:
- are in good health
- don’t have any preexisting conditions that can complicate a pregnancy
- eat well throughout your pregnancy