Secondary infertility refers to the difficulty in becoming pregnant or completing a pregnancy following the successful birth of one or more children. Potential treatments range from ovulation-stimulating medications and surgical procedures to assisted reproductive technologies such as in vitro fertilization (IVF).
Overview
Understanding Secondary Infertility
Secondary infertility describes the inability to conceive or carry a baby to term after a previous natural childbirth, without the aid of fertility-enhancing interventions like IVF. Typically, healthcare professionals consider this diagnosis when a couple fails to conceive after 6 to 12 months of trying, depending on age and individual circumstances.
How prevalent is it?
Secondary infertility is just as prevalent as primary infertility, impacting roughly 11% of couples in the United States.
Symptoms and Causes
What indicates secondary infertility?
The key symptom is the inability to become pregnant after having one or more biological children. For individuals under 35, this condition is usually suspected after a full year of unprotected, regular intercourse without success. For those over 35, the timeline is shortened to six months.
Primary causes of secondary infertility
Both partners can contribute to secondary infertility, which often stems from a combination of factors or remains unexplained. Statistically, causes are evenly distributed between male and female factors, with a significant portion remaining idiopathic.
Frequent contributors include:
- Suboptimal sperm or egg quality.
- Advanced parental age.
- Issues arising from past pregnancies.
- Post-surgical complications.
- Significant weight gain or elevated body mass index (BMI).
- Ongoing medical treatments or conditions.
- Infections transmitted sexually.
- Habits such as smoking and alcohol use.
Factors affecting female fertility
Women may experience secondary infertility due to egg quality, anatomical issues, health disorders, or lifestyle elements.
Egg quantity and quality
Females are born with a fixed number of eggs that deplete with age. As a woman nears her 40s, both the count and genetic integrity of her eggs typically decline. Genetic disorders, autoimmune diseases, and prior exposure to surgery or radiation may further reduce egg viability.
Physical obstructions or damage
Previous infections or surgeries may injure the uterus or fallopian tubes, impairing egg transportation and implantation. Conditions such as pelvic inflammatory disease (PID), gonorrhea, or chlamydia may obstruct fallopian tubes. Surgical scars, fibroids, and uterine polyps can also disrupt fertility.
Polycystic Ovary Syndrome (PCOS)
This endocrine disorder often results in irregular ovulation due to hormonal imbalances, significantly hindering conception efforts.
Endometriosis
When endometrial-like tissue grows outside the uterus, it can interfere with fertility. Although widespread, not every case leads to infertility.
Body weight and lifestyle adjustments
Sudden or significant weight gain may disrupt hormonal balance and ovulation. Lifestyle habits like alcohol consumption and smoking may also impair fertility.
Factors contributing to male infertility
Men may encounter secondary infertility due to hormone deficiencies, medical issues, or unhealthy lifestyle choices.
Low testosterone levels
This hormone is vital for sperm development. Levels may decrease due to age, testicular injury, or underlying health conditions such as:
- Genital infections
- Thyroid disorders
- Diabetes
- Tuberculosis
- Mumps and smallpox
- Blood diseases
- Benign tumors
- Severe emotional stress
- Heart conditions and other systemic illnesses
This condition is medically referred to as hypogonadism, affecting approximately 2% of men and increasing with age.
Varicocele in the testes
This refers to swollen veins within the scrotum, which may disrupt sperm production and quality, affecting roughly 30% of men with infertility issues.
Poor semen quality
The fluid that transports sperm can decline in quality with age, particularly after 40.
Reduced sperm count
A count below 15 million sperm per milliliter of semen is classified as low (oligospermia), impacting the likelihood of conception.
Prostate issues
An enlarged or surgically removed prostate can interfere with ejaculation and sperm delivery, potentially causing infertility.
Medications that impair fertility
Certain drugs, including some antibiotics and those used to manage blood pressure, can reduce sperm count or quality. Treatments for the following ailments can have similar effects:
- Prostate cancer
- Fungal infections
- Urinary tract infections
- Ulcerative colitis
- Autoimmune disorders like arthritis and gout
- Chronic pain
- Cancer treatments
- Neurological and psychiatric conditions such as epilepsy and schizophrenia
Environmental and lifestyle influences
Exposure to toxic substances and unhealthy lifestyle choices can severely affect fertility. These include:
- Use of sperm-toxic lubricants such as oils or petroleum jelly
- Environmental toxins like pesticides, lead, and industrial chemicals
- Heat exposure and substantial weight gain, which can alter hormone levels
Who faces increased risk?
Several factors may elevate the risk of developing secondary infertility, including:
- A history of sexually transmitted infections or pelvic inflammatory disease
- Irregular menstrual cycles
- Previous miscarriages
- Low sperm count
- Hormonal disruptions
