Causes of infertility among women

 
Businesswoman in white

Major causes of infertility among women include:

1. Hormonal imbalance

2. Structural abnormalities in uterus or the fallopian tubes

3. Ovulatory disorders

4. Endometriosis

5. Psychological problems

It is important to understand the basics of structure and functioning of the female reproductive system to understand further about these causes.

 

Structure of female reproductive system

 
Businesswoman in white

The female reproductive system consists of several external and internal reproductive organs, all of which play unique and critical roles to ensure fertility of women.


External reproductive organs (labia majora, labia minora, clitoris and glands) facilitate coitus, provide passage to the sperm and protect internal organs from infections.​


Internal reproductive organs (uterus, fallopian tubes and ovaries) play a central role in the hormonal regulation and ability of a woman to reproduce.

  1. Uterus (womb) is where the foetus implants and develops inside the uterus

  2. Ovaries are a pair of glands located on either side of the uterus and house millions of eggs, which a female foetus acquires in her mother’s womb. Ovaries become functional at puberty and start producing sex hormones and mature eggs.

  3. Fallopian tubes are narrow tubes, which serve as pathways for the eggs to travel from the ovaries to the uterus. Fertilisation of egg normally occurs in the fallopian tubes, from where the fertilised egg moves to the uterus to get implanted in the lining of uterus.

 

How does the female reproductive system work

 
Businesswoman in white

The functioning of female reproductive system revolves around the monthly cycle of hormonal activity, which results in a series of changes in the female reproductive organs, thus preparing her body for pregnancy.


Menstrual cycle begins in girls at puberty and continues until menopause. The entire cycle is governed by hormones FSH and LH, which are secreted by the pituitary gland located inside brain.


Menstrual cycle can be divided into 3 phases based on the activity in the ovary (ovarian cycle) and in the uterus (uterine cycle). The ovarian cycle can be divided into follicular phase, ovulation and luteal phase. Likewise, the uterine cycle can be divided into menstruation, proliferative phase and secretory phase.

Let's understand a bit more about the ovarian cycle.

1. Follicular phase: This phase is marked by beginning of menstruation at the beginning of a new menstrual cycle. Pituitary gland secrets Follicle Stimulating Hormone (FSH) to stimulate the ovaries, as a result of which, a number of eggs start growing in the ovaries. Each egg is contained in a bag of fluid and is called a follicle. At the end of this phase, a single dominant follicle is ready for ovulation to release the egg.


2. Ovulatory phase: Ovulation, the process of release of eggs, is triggered by release of Luteinising Hormone (LH) from the pituitary gland. The egg, thus released, is captured by the the fallopian tubes, which push it gently towards the uterine cavity.


3. Luteal phase: Shell of the follicle remaining after ovulation develops into "corpus luteum", which releases progesterone and oestrogen. Progesterone supports pregnancy by causing secretory changes in the uterine lining, which enable the fertilised egg to get implanted.

Egg gets fertilised by the sperm inside the fallopian tube, from where the fertilised egg travels to the uterus to get implanted, thereby resulting in pregnancy. Corpus luteum continues to release hormones to support pregnancy.


In case there is no pregnancy, the corpus luteum dissolves. As soon as the hormone secretion stops the uterine lining sheds off leading to menstruation and initiation of a new menstrual cycle.

 

Evaluation of female partner

 

Evaluation of the female partner begins with detailed history, physical examination and hormonal assessment. Investigations required for assessment of an infertile woman typically include -
1. Blood tests for hormonal evaluation 
2. Ultrasound (serial scans) to assess anatomy of the reproductive system and maturation of follicles
3. Invasive tests for assessment of the structural integrity of the reproductive system