Me And My Periods

In a life cycle, a woman’s body is vulnerable to a variety of changes. The cycle of these changes occurs in women every month, positively for pregnancy is called the menstrual cycle. When an ovum is unfertilized, the uterus lining sheds and leads to a haemorrhage, called menstruation. In a girl, menstruation starts from the age of 10 to 15 when she attains puberty and this beginning is known as menarche. The ending of menstruation is known as menopause which takes place in your 40s or 50s.

The first day of bleeding is marked as the first day of a menstrual cycle and the period from one menstrual cycle to another can vary from 28 to 30 days.

Female reproductive system and organs involved in this cycle they mainly include:

A pair of ovaries that store, nourish and release ova.
Uterus (womb), where implantation of a fertilised egg takes place and the foetus develops.
Pair of the fallopian tubes connecting the ovaries and uterus.

Phases of the Menstrual Cycle

The menstrual cycle is divided into four phases, namely:

Menstrual phase: Day 1, uterus lining which is prepared for implantation starts to shed which lasts 3 to 5 days.
Follicular phase: In this phase, the primary follicle starts developing into a mature Graffian follicle. The endometrium also starts proliferating. The uterus starts preparation for another pregnancy.
Ovulatory phase: Mid-cycle phase, this is the phase in which ovulation takes place i.e., day 13-17. The end of the follicular phase along with the ovulation period defines the fertilisation period.
Luteal phase: It is the post-ovulation phase, where the fate of the corpus luteum is decided. If fertilisation occurs, pregnancy starts. If fertilisation doesn’t occur, it marks the onset of another cycle.

Role of Hormones in Menstrual Cycle

The chemical messengers in our body called hormones, released by various endocrine glands are responsible for many changes in a human body. Menstruation is a slave to certain hormones. Every phase of the menstrual cycle is influenced by a female hormones namely estrogen, progesterone, Follicle-stimulating hormone (FSH) and Luteinizing Hormone (LH). The variation in the level of each of these hormones decides the phase which a girl undergoes.

FSH & LH are secreted by the anterior pituitary. FSH stimulates the growth of ovarian follicles that secrete estrogen. Progesterone is secreted by the corpus luteum.

As we can see in the above diagram, the secretion of FSH and LH gradually increases during the follicular phase. They stimulate the development of follicles and the release of estrogen from them. Estrogen stimulates the proliferation of the endometrium. The level of LH and FSH peaks in the middle of the cycle. LH induces ovulation. There is a sudden surge in LH level just before ovulation. After ovulation, the ruptured follicle develops into the corpus luteum, which secretes progesterone, hence the level of progesterone increases in the luteal phase. Progesterone is required for the maintenance of the endometrium for implantation. In the absence of fertilisation, corpus luteum regresses and progesterone level decreases. It leads to the disintegration of the endometrium and menstrual flow occurs.

What are periods?

A period is the part of the menstrual cycle when a woman bleeds from her vagina for a few days and it is made up of blood and the womb lining. The first day of a woman’s period is day 1 of the menstrual cycle.

“Periods last around 2 to 7 days, and women lose about 3 to 5 tablespoons of blood in a period,” says Belfield.

Some women bleed more heavily than this, but help is available if heavy periods are a problem.

Preparing for ovulation

At the beginning of your cycle follicle-stimulating hormone (FSH) is produced by the pituitary gland in your brain. This is the main hormone involved in stimulating your ovaries to produce mature eggs. Follicles are the fluid-filled cavities in your ovaries. Each follicle contains one undeveloped egg. The FSH stimulates a number of follicles to develop and start to produce the hormone estrogen. Your level of estrogen is at its lowest on the first day of your period. From then on, it starts to increase as the follicles grow.

Now while a number of follicles initially begin to develop, normally one follicle becomes “dominant” and this egg matures within the enlarging follicle. At the same time, the increasing amount of estrogen in your body makes sure that the lining of your womb is thickening with nutrients and blood. This is so that if you do get pregnant, the fertilized egg will have all the nutrients and support it needs to grow. High estrogen levels are also associated with the appearance of ‘sperm-friendly’ mucus (or, to give it its technical name, fertile cervical mucus FCM). You may notice this as a thin, slippery discharge that may be cloudy white. Sperm can swim more easily through this mucus and can survive in it for several days.

Preparing for the next period...

As the empty follicle shrinks, if the egg is not fertilized, levels of estrogen and progesterone decrease. Without the high levels of hormones to help maintain it, the thick womb lining that has been built up starts to break down, and your body sheds the lining. This is the start of your period and the beginning of your next menstrual cycle.

If the egg has been fertilized, it may successfully implant itself into the womb lining. This usually takes place about a week after fertilization.

As soon as the fertilized egg has implanted, your body starts producing the pregnancy hormone, human Chorionic Gonadotrophin (hCG), which will keep the empty follicle active. It continues to produce the hormones estrogen and progesterone to prevent the lining of the womb from being shed, until the placenta (which contains all the nutrients the embryo needs) is mature enough to maintain the pregnancy.