Age-related infertility is a common and significant issue faced by women, especially as they delay childbearing into their 30s and 40s. As women age, their fertility declines due to changes in the quantity and quality of their eggs, among other physiological factors. While advances in reproductive medicine have provided more options for older women, understanding how age impacts fertility is crucial for those trying to conceive.
This article will explore the causes, risk factors, and treatment options for age-related infertility in women.
Causes of Age-Related Infertility
The biological clock plays a critical role in female fertility. As women age, several key changes occur in the reproductive system, making conception more difficult. The primary factors are the reduction in both the quantity and quality of eggs, as well as changes in reproductive health and hormonal regulation.
1. Decreased Ovarian ReserveThe term ovarian reserve refers to the number of eggs a woman has left in her ovaries. Women are born with all the eggs they will ever have—approximately 1 to 2 million at birth. By puberty, this number has already decreased to around 300,000 to 400,000. As women age, the number of eggs continues to decline, with a sharp drop occurring after age 35.
- Egg Quantity: By age 35, fertility starts to decline significantly, and by the time a woman reaches her early 40s, her chances of conceiving naturally decrease considerably.
- Egg Quality: Not only does the number of eggs decline, but their quality deteriorates as well. Aneuploidy, or chromosomal abnormalities in eggs, becomes more common with age, which can lead to infertility, miscarriage, or birth defects.
- Follicle-Stimulating Hormone (FSH): As women age, their bodies produce higher levels of FSH in an effort to stimulate the ovaries to release eggs. Elevated FSH levels, particularly after age 40, indicate diminished ovarian reserve and lower fertility potential.
- Anti-Müllerian Hormone (AMH): AMH levels are a marker of ovarian reserve. AMH levels decline as a woman ages, reflecting the reduced quantity of eggs in the ovaries.
- Progesterone: Progesterone is necessary to maintain the uterine lining for implantation and support early pregnancy. Age-related declines in progesterone can contribute to fertility issues and higher risks of miscarriage.
With aging, eggs are more likely to carry chromosomal abnormalities. This can result in:
- Infertility: Abnormal eggs may not be able to be fertilised or may fail to implant.
- Miscarriages: A significant portion of miscarriages, especially in older women, are due to chromosomal abnormalities in the embryo.
- Congenital Disorders: Babies born from older mothers are at higher risk for genetic conditions.
While ovarian aging is the primary cause of age-related infertility, the uterus and endometrium (lining of the uterus) can also be affected by aging. Over time, the endometrial lining may become less receptive to the implantation of embryos. Age-related health issues such as uterine fibroids and adenomyosis can further reduce fertility.
5. Increased Risk of Other Health ConditionsAs women age, they are more likely to develop other health conditions that can affect fertility, including:
- Endometriosis: A condition where tissue similar to the uterine lining grows outside the uterus, often worsening with age and causing pain and infertility.
- Polycystic Ovary Syndrome (PCOS): While PCOS often affects younger women, it can persist into older age, leading to continued ovulatory dysfunction.
- Chronic Illnesses: Health issues such as diabetes, obesity, and thyroid disorders are more prevalent as women age, all of which can impact fertility.
Risk Factors for Age-Related Infertility
While age itself is the biggest factor in age-related infertility, several lifestyle and environmental factors can further contribute to the decline in fertility with advancing age:
1. Age- After 35: Fertility begins to decline significantly after age 35. Women have a lower ovarian reserve, and the chances of conception per cycle drop. The likelihood of miscarriage and chromosomal abnormalities also increases.
- After 40: By the age of 40, a woman’s chances of becoming pregnant naturally decrease to about 5-10% per month. The majority of eggs will have chromosomal abnormalities, which dramatically increases the risk of miscarriage and congenital defects.
Many women are choosing to delay having children due to personal, educational, or career reasons. While this is a growing trend, it increases the risk of facing infertility challenges, as fertility naturally declines with age.
3. Lifestyle Factors- Smoking: Smoking accelerates egg loss and can bring on early menopause. It also damages the ovaries and leads to poorer outcomes in assisted reproductive technologies.
- Obesity: Being overweight or obese can cause hormonal imbalances, particularly affecting insulin levels, which can impact ovulation and overall fertility.
- Poor Diet: A diet lacking essential nutrients can affect overall reproductive health. High sugar intake, processed foods, and excessive alcohol consumption can negatively impact fertility.
- Stress: Chronic stress can interfere with hormone production and regulation, potentially delaying or preventing ovulation.
- Previous Surgeries: Any surgeries on the reproductive organs, such as those for ovarian cysts or fibroids, may have damaged reproductive tissues or led to scarring.
- Sexually Transmitted Infections (STIs): Untreated STIs can lead to pelvic inflammatory disease (PID), causing scarring and blockages in the fallopian tubes, further decreasing the chances of conception.
Diagnosis of Age-Related Infertility
If a woman over 35 has been trying to conceive for six months or more, or a woman over 40 for three months, it’s recommended that she seek fertility evaluation. The diagnostic process typically involves:
1. Hormonal Testing- Anti-Müllerian Hormone (AMH) Levels: AMH is a marker of ovarian reserve, and low levels can indicate diminished ovarian function.
- Follicle-Stimulating Hormone (FSH) Levels: High levels of FSH, particularly on the third day of a menstrual cycle, can indicate that the body is trying to compensate for a decline in egg quality or quantity.
- Oestradiol Levels: Elevated oestradiol levels, particularly early in the menstrual cycle, can suggest reduced ovarian reserve.
- Antral Follicle Count (AFC): An ultrasound can measure the number of small follicles in the ovaries that have the potential to develop into eggs. A low AFC suggests diminished ovarian reserve.
- Pelvic Ultrasound: To assess the uterus and ovaries for any structural abnormalities like fibroids, polyps, or cysts.
Ovarian reserve tests provide an indication of how many eggs a woman has left. This is a critical component of fertility evaluation, especially for older women.
4. Uterine EvaluationTests such as hysteroscopy or saline sonohysterography can be used to examine the uterine lining for polyps, fibroids, or other abnormalities that may interfere with implantation.
Treatment Options for Age-Related Infertility
Although age-related infertility is a natural part of the aging process, modern fertility treatments offer various options to help women conceive, even later in life.
1. Lifestyle ModificationsWhile age-related fertility decline cannot be reversed, adopting healthier lifestyle practices may help improve fertility outcomes:
- Maintaining a Healthy Weight: Achieving a normal body mass index (BMI) can help regulate ovulation and improve reproductive health.
- Nutrition: A diet rich in antioxidants, healthy fats, and vitamins can support egg health and overall fertility. Supplements like pre-Conceive may help improve egg quality in older women.
- Quit Smoking: Quitting smoking is essential, as it accelerates egg loss and can negatively impact fertility treatment outcomes.
For women who are still ovulating, medications like clomiphene citrate (Clomid) or letrozole can stimulate the ovaries to release eggs, increasing the chances of conception.
3. In Vitro Fertilisation (IVF)IVF is often the most effective option for older women facing infertility. The process involves stimulating the ovaries to produce multiple eggs, retrieving those eggs, fertilising them in a lab, and then transferring one or more embryos to the uterus.
- Preimplantation Genetic Testing (PGT): In IVF, embryos can be screened for chromosomal abnormalities before being transferred, reducing the risk of miscarriage or birth defects.
- Egg Donation: For women with diminished ovarian reserve or poor egg quality, using donor eggs is a common option. Donor eggs from a younger woman have higher chances of successful implantation and a healthy pregnancy.
For younger women who wish to delay childbearing, egg freezing is a proactive measure to preserve fertility. By freezing eggs during peak reproductive years (typically before age 35), women can later use these eggs in IVF when they are ready to conceive, even in their 40s or beyond.
5. Hormone Replacement Therapy (HRT)In cases of premature ovarian failure or menopause, hormone replacement therapy can help regulate the menstrual cycle and improve the endometrial lining in preparation for assisted reproductive treatments.
Conclusion
Age-related infertility is a natural consequence of the aging process, largely due to the decline in egg quality and quantity. While fertility begins to decline around age 35 and drops sharply after 40, many women are still able to conceive with the help of fertility treatments such as IVF, egg donation, or lifestyle changes.
Those who are trying to conceive later in life should seek early evaluation and guidance from fertility specialists. Although age-related infertility presents challenges, modern reproductive technologies offer hope for many women looking to expand their families.
