Female fertility: development of the female reproductive system

Female fertility can be defined as the ability of a woman to conceive and carry a pregnancy for 9 months, which is called full-term pregnancy.

In this sense, and for a woman to be considered fertile, she has to meet two basic requirements:

• Her ovaries are able to produce good-quality eggs in order for the sperm to be able to penetrate and fertilize them.
• Her uterus is able to carry a pregnancy to term, from fertilization to labor.

In women, fertility is governed by both the female reproductive system and the endocrine system. They need to be properly regulated and coordinated in order for all the steps involved in the process to be successful.

The different sections of this article have been assembled into the following table of contents.

Female reproductive system

The anatomy of the female reproductive system can be classified into two groups depending on whether we are talking about the external or the internal organs. To follow, we will describe each of these female sexual organs in detail.

External organs

The whole set of external female genitalia is known as the vulva. It includes the following parts:

Mons pubis or mons Venus

a rounded mass of fatty tissue that covers the pubic bone, covered by skin and pubic hair. Its function is to protect the internal organs by absorbing shocks.

Labia majora

consists of two cutaneous folds that protect the vulva. They work by preventing the entrance of bacteria into the female reproductive system.

Labia minora

made of two folds of skin which functionto protect the opening of the vagina and keep the internal organs at the correct temperature.

Vulval vestibule

this part of the external organs includes the urethral orifice, the opening of the vagina, the hymen, the Bartholin's glands, and the Skene glands (a.k.a. periurethral or paraurethral glands).

Clitoris

a cylindrical, button-like erectile organ that is made of multiple sensory nerve endings. It is very sensitive to sexual stimulation.

External female reproductive organs

The perineum is the region where the pelvic floor muscles are located. It is composed of muscles that surround and protect both the vulva and the anus.

The breasts or mammary glands are also considered to be external female reproductive organs. Their function is to secrete milk and feed infants after childbirth.

Internal organs

The female internal reproductive organs are the ones responsible for human reproduction and are located within the abdominal cavity. Each one of them is listed below:

Vagina

a muscular and tubular part of the female reproductive system which connects the uterus with the exterior. It allows for the entrance of the penis during sexual intercourse, and is acts as the birth canal to deliver a newborn.

Cervix

the cervix is the lower part of the uterus and connects it with the vagina.

Uterus or womb

consists mostly of smooth muscle (i.e. myometrium), and is the place where pregnancy and fetal development occur. Its inner layer, the endometrium, thickens on a monthly basis to receive the embryo, and shreds in the form of menstrual flow if embryo implantation does not take place.

Fallopian tubes

these tubes, approximately 10cam in length, connect the ovaries with the womb. The sperm meets the egg here to produce the all important fertilization.

Ovaries

the female gonads , one on each side of the uterus. Their function is to produce egg cells and release one mature egg during the fertile days of the woman's menstrual cycle. They are  also responsible for the production of female sex hormones.

Internal female reproductive apparatus

If there is an abnormailty that prevents the woman from conceiving, she will be diagnosed with female sterility or infertility.  The difference between these two terms is whether or not fertilization is possible. Nevertheless, thanks to the progress made in the field of assisted reproductive technology (ART) it is possible for women to get pregnant in spite of infertility.

When do females become fertile?

For a woman to be fertile, all her reproductive organs should work properly. This is achieved thanks to the female anatomy and the correct functioning of the endocrine system. The endocrine system is responsable for the release of the appropriate hormones.

During childhood, the reproductive system does not release sex hormones, and the body works exactly the same for boys and girls. The only thing that allows us to distinguish between them are their primary sexual characteristics, that is, their sex organs.

When girls start puberty, which usually occurs at age 11 or 12, their ovaries start working as the hormones FSH and LH are released by the pituitary gland. These two hormones start the development of the female reproductive organs.

From that moment on, the ovaries start secreting the female hormones estrogens and progesterone. Moreover, the secondary sexual characteristics of females start developing:

• Growth of breasts
• Development of the skeleton: the pelvis is adapted for pregnancy and childbirth
• Growth of pubic hair
• Start of menstruation and ovulation
• Voice changes

The onset of female fertility

A normal regulation of the menstrual cycle should occur for a woman to be fertile. The length of a typical cycle is 28 days approximately. The fertile window, which is the moment when ovulation takes place, occurs halfway through the cycle. It is during the woman's fertile window when she should try to conceive, as her chances for getting pregnant will be considerably higher.

Can female fertility be improved?

Many women ask themselves this question. The answer is that there are some tips to improve female fertility, although there is nothing miraculous.

For example, leading a healthy lifestyle and following a balanced diet has benefits for a woman's fertility. It is a good idea to cut down on processed carbohydrates since they could cause insulin resistance and alter ovulation. Another example would be caffeine which causes alterations in estradiol levels or tobacco which reduces uterine response.

Advice to improve female fertility

In addition, it is important to drink 2 liters of water daily. Sometimes, specialists also recommend taking a vitamin supplement to help increase the possibility of pregnancy.

FAQs from users

At what age is pregnancy most likely to occur?

From 20 to 35 years of age there is a greater probability of achieving a pregnancy naturally. It is from that age when the oocyte quality decreases with a considerable slope, establishing that 10 years before the theoretical menopause (around 40 years of age) the chances of pregnancy are, therefore, very low.

What are the accessory gland of the female reproductive system?

The accessory glands are the Bartholin's glands and the paraurethral glands found in the vaginal vestibule. They are very tiny, secretory glands that secrete fluid to lubricate the labia during intercourse and also secrete pheromones involved in sexual attraction.

Is the intake of canned foods advisable when it comes to female fertility?

No. Both canned and plastic-packed foods may contain traces of Bisphenol A, a chemical compound that acts as an endocrine disruptor and interferes with the hormone cycle. Therefore, bisphenol A could worsen the quality of the oocytes and make it difficult to get pregnant.

Can a woman get pregnant just after puberty?

A woman is at her most fertile when she approaches 20 years of age. However, pregnancy is possible at younger ages once menstruation has arrived. Therefore, good sex education is very important to raise awareness among young people about the use of condoms to avoid unwanted pregnancy.

When do women ovulate?

In women with a normal 28-day menstrual period, the most fertile period, that is, ovulation occurs 14 days after the first day of the last menstruation. Nonetheless, the days before and after this date are considered to be fertile, which means that the woman could get pregnant.

What age do girls get their period?

First and foremost, it should be clear that there is no right age for the first period to show up. Although most girls start to menstruate between ages 10 and 15 years, one should keep in mind that every girl's body has its own schedule. A common sign that a girl is going to get her first menstrual period is vaginal discharge fluid, which usually begins 6-12 months before it appears.

When does a woman go through menopause?

Menopause is the end of a woman's fertility and usually starts around age 51, provided that it occurs naturally. Nevertheless, it can happen earlier, which is known as premature menopause or early menopause. Once it starts, it should stop completely within about 4 years, as it involves three phases: perimenopause, menopause, and postmenopause.

Recommended reading

Alterations or disorders of the female reproductive system can make it difficult or impossible for a woman to get pregnant. You can learn more about them in the following article: Diseases that Cause Female Infertility.

Are you TTC and would like to start using OPKs or ovulation calculators? It will be a piece of cake after reading this guide: How Do Ovulation Calculators Work?

A woman's ovarian reserve or egg supply is composed of the total amount of eggs contained within her ovaries, which diminishes with age. If you want to delve deeper into this topic please click here: What Is the Ovarian Reserve?

References