Infertility: Nursing

Infertility is defined as the inability to conceive after 12 months of regular, unprotected sexual intercourse in couples of reproductive age. Infertility can affect one or both partners, or, in some cases, no cause can be found in either partner, in which case it’s termed unexplained infertility.

Now, let’s go over some anatomy and physiology when it comes to conceiving. The female gonads are called ovaries, which are paired reproductive organs that produce sex hormones, namely estrogen and progesterone; as well as gametes, called oocytes, in the process known as oogenesis.

These functions are an integral part of the menstrual cycle, which usually lasts around 28 days and can be divided in two phases. First, there’s the follicular phase, during which estrogen rises, and the oocytes mature until ovulation, which typically occurs on day 14 of a 28 day cycle.

During ovulation, the mature oocyte is released in the fallopian tube and it can possibly be fertilized by a male gamete, called a sperm. If fertilization occurs, the fertilized egg travels down the Fallopian tube and implants into the uterine lining, so pregnancy occurs.

If fertilization doesn’t occur, ovulation is followed by the luteal phase, during which progesterone rises and peaks, and then hormone levels gradually decrease until menstruation occurs, and the cycle starts all over again.

The menstrual cycle is primarily controlled by two pituitary hormones: luteinizing hormone or LH for short, and follicle-stimulating hormone or FSH for short; but a normal concentration of several other hormones, including thyroid hormones, cortisol and prolactin, is needed for the menstrual cycle to unfold optimally.

On the other hand, the male gonads are called testicles, or testes, which are also paired reproductive organs that lie in the scrotum. The testes produce the sex hormone testosterone, and they’re also where spermatogenesis, or the development of sperm, happens. Just like oogenesis, spermatogenesis is also controlled by LH and FSH; the difference is that spermatogenesis occurs constantly, and doesn’t follow a cyclical pattern. The mature sperm are stored in the epididymis, which is a little coiled tube found on one side of the testicle. During ejaculation, sperm is released from the epididymis and travels through a series of reproductive ducts, including the vas deferens, to eventually exit the body through the urethra.

Finally, remember that sex hormones also play a role in the normal reproductive function and the development of secondary sex characteristics. Estrogen and progesterone control menstrual cycles; and enable the normal development of female secondary sex characteristics, such as enlargement of the breast. Testosterone, on the other hand, is needed for spermatogenesis, and the development of male secondary sex characteristics, such as facial and body hair, enlargement of the larynx, and maturation of voice.

That being said, infertility can affect one or both partners. The causes of infertility in individuals with female reproductive organs can be subdivided into two main groups. The first group covers ovulatory dysfunction, which can result from premature ovarian failure, meaning the ovaries run out of oocytes before menopause; as well as endocrinological, genetic or developmental causes.

Endocrinological causes include polycystic ovarian syndrome, or PCOS, which is a condition characterized by excess testosterone production; Cushing syndrome, or excess cortisol production; hyperprolactinemia where a tumor in the pituitary overproduce prolactin; and hyperthyroidism or hypothyroidism.

Another cause is functional hypothalamic amenorrhea, which is when the hypothalamus doesn’t stimulate pituitary production of FSH and LH enough. This can be caused by excessive exercising, stress, or having a body mass index, or BMI, below 18.5 kg/m2, or over 25 kg/m2.

Alternatively, the most common genetic or developmental causes include Turner syndrome, which is when the individual only has one X chromosome instead of two; or Kallman syndrome, which is when the hypothalamic neurons that produce gonadotropin-releasing hormone, or GnRH, don’t develop properly.

On the other hand, the second group covers conditions that can affect the normal anatomy of the reproductive system, such as adhesions of the Fallopian tubes; uterine tumors; pelvic inflammatory disease caused by sexually transmitted infections or other infections in the female reproductive organs; and endometriosis, which is when the lining of the uterine cavity, called the endometrium, grows in other places, such as the ovaries or fallopian tubes.

On the flip side, causes of infertility in individuals with male reproductive organs can be classified into three main groups. The first group includes pre-testicular causes, such as Kallman syndrome; Prader-Willi syndrome, a genetic condition caused by a gene defect located on chromosome 15, which disrupts the function of the hypothalamus; as well as hyperprolactinemia.

The second group covers testicular causes, such as Klinefelter syndrome, which is when they have an extra X chromosome; testicular tumors; cryptorchidism, which occurs when testicles fail to descend into the scrotum; or a varicocele, which is when the veins in the scrotum enlarge and compress the testes.

Finally, the third group covers post-testicular causes, such as tumors and adhesions of the male reproductive ducts; as well as cystic fibrosis, which is a genetic condition that can cause a congenitally absent vas deferens; and retrograde ejaculation, which is when sperm is released from the urethra into the bladder, instead of outside the body, during ejaculation.

Additional causes of infertility in individuals assigned male or female at birth include trauma, infections, and radiation or surgery in the head area, which can impair pituitary production of FSH and LH.

Finally, common risk factors for infertility include advanced age; unhealthy lifestyle habits, such as smoking, and use of alcohol and drugs; non-malignant chronic conditions, like diabetes; sexually transmitted infections; and finally, trauma, infections, and radiation or surgery in the head or reproductive area.

Now, let’s switch gears and look at the pathology of infertility. In the female reproductive system, there are two types of ovulatory dysfunction: oligoovulation, which is when the ovaries don’t release an egg every month; and anovulation, which is when an egg isn’t released at all.

Both can be linked with hormone imbalance and damage or abnormalities of the ovary. With PCOS, there’s excess testosterone production which can negatively impact oocyte maturation and release.

Cushing syndrome increases cortisol levels, hyperprolactinemia increases prolactin levels and hyper and hypothyroidism cause abnormal levels of thyroid hormone. All three can cause dysregulation of FSH and LH secretion.

In Kallman syndrome there’s inadequate production of GnRH from the hypothalamus leading to decreased release of FSH and LH, disrupting the normal ovulation process. Individuals with Turner syndrome typically have small, atrophied ovaries.

Next up are adhesions of the Fallopian tubes, or inflammation and scarring from pelvic inflammatory disease which can result in anatomical barriers and disrupt the journey of the fertilized egg into the uterine cavity. And with endometriosis, endometrial tissue can develop in the fallopian tubes or the ovaries, which either obstructs the passage through the tubes, or impairs ovulation, respectively. Finally, uterine tumors can disrupt the normal anatomy of the uterine cavity, thereby preventing the fertilized egg from attaching to the uterine wall.

Now, let’s switch our focus to the pathology of the male reproductive system. Pre-testicular causes impair pituitary production of FSH and LH, impairing spermatogenesis. Testicular problems are associated with poor semen quality and low sperm count. And finally, post-testicular conditions usually result in the obstruction of the ejaculatory system.