Understanding the menstrual cycle
Understanding Your Cycle
A general understanding of the female reproductive process will help you prepare for pregnancy and help increase your chances of conception.
The menstrual cycle is essential for reproduction and can be divided into 3 phases (follicular phase, ovulatory phase and luteal phase). This cycle is stimulated by changing levels of hormones throughout the 3 phases. The brain plays an essential part as it controls and balances the different hormone levels in the body. The menstrual typical cycle recurs every month. The average length is 28 days, but it can vary from 21 to 35 days.
The first phase of your cycle is called the follicular phase. This begins on Day one of your cycle, which is the first full day of menstrual bleeding when the lining of the uterus starts to break down because the egg during the previous cycle has not been fertilized. Your body is now getting prepared to start a new cycle. For most women period lasts typically from 3 to 5 days.
The next phase is the ovulatory phase Your body prepares for ovulation thanks to two hormones: FSH (Follicle Stimulating Hormone) and LH (Luteinizing Hormone). A follicle is one of the many tiny sacs within an ovary that contains a developing egg. FSH stimulates a follicle to grow and the egg within it to ripen. LH stimulates the follicle to manufacture and secrete estrogen.
You're in the ovulatory phase now, when increasing estrogen levels cause the lining of the uterus to re-nourish with nutrients and blood. The heightened levels of estrogen also produce a change in cervical mucus, causing it to thin and take on a slippery consistency. The change in cervical fluid makes it easier for sperm to make their way toward a waiting egg. All of this usually takes place between days 7 and 11 in a woman's cycle.
When the amount of estrogen produced in your body reaches a certain level, there is a surge of LH. 24 to 36 hours after this LH surge, the follicle will release the completely ripened egg that will travel from the fallopian tube to the womb. This is known as ovulation.
The final and third phase of your menstrual cycle is called the luteal phase. This follows ovulation. The corpus luteum (follicle in which the egg burst through) produces progesterone and oestrogen. The increased production of progesterone maintains the thickness of the uterus so that a fertilized egg has a better chance of implanting.
If the egg is not fertilized within 24 hours, the corpus luteum recesses and hormone production slows down. After around 11-14 days, the lining of the womb will break down. This is known as your period and your menstrual cycle begins again*.
* Information supplied by Church & Dwight Co., Inc. and Sharron Trotter, independent midwife, www.sharontrotter.org.uk
Common Questions
1 – When is the best time to try for a baby?
The best time to become pregnant is during the ovulation. This “fertility window” will give you the opportunity to try for a baby during 3 to 4 days. Even if eggs live up to 24 hours, the sperm of your partner can live up to 5 days. So it makes sense for the sperm to have already made their journey to the egg, ready and waiting for the egg when it is released. If you wait until ovulation has happened to try for a baby, the chances of the egg and sperm finding each other reduces*.
2 – Are there signs that I am ovulating?
Yes there are several signs to tell if you are ovulating
- Basal body temperature (BBT): daily temperature recordings show that at ovulation your temperature spikes by 0.5 -1 degree centigrade.
- Cervical mucus changes: around the time of ovulation the mucus in the cervix changes from being thick and opaque to become thin, clear and stringy. This is also a sign that a woman is at her most fertile.
- Blood tests and ultrasound scans of the ovary will give conclusive evidence of ovulation but are not usually required unless infertility is suspected. Speak to your GP if you have any concerns.*
3 – How can I predict the best two days to become pregnant?
First Response® Ovulation Test is the perfect tool to help you increase your chance of conception. It can be bought from Boots and chemists. First Response® Ovulation Test includes 5 ovulation predictor sticks to help you predict your most fertile 24 hours of the month and instructions. These tests measure the LH in your urine to detect when the "LH surge" occurs FIRST RESPONSE® is simple, easy-to-use and highly accurate (over 99 percent in laboratory testing). To detect the "LH surge," you simply test your urine near mid-cycle to determine an increased level of LH. (See instructions inside the package for more detailed information.) Most women will ovulate within 24 to 36 hours after the "LH surge" is detected. If you have intercourse at any time during the 24 to 36 hours after you detect your "LH surge," you will maximize your chance of becoming pregnant.
4 – I would like to get pregnant but am taking the contraceptive pill at the moment.
If you are using the Pill you should stop taking it a few months before you wish to become pregnant. It takes at least a month for your cycle to get back to normal*.
5 – I have been trying to conceive for 6 months and am worried is hasn’t happened yet.
It can take a while to fall pregnant but most couples will conceive within one year. You should try to relax as stress can affect your fertility and upset your cycle although this is easier said than done.
However, if you have failed to become pregnant after 12 months of actively trying then maybe you should consider seeing your GP who can refer you to an infertility specialist*.
For further advice on healthy conception with Food for Life, you can visit our section
* Information compiled with the help of Sharon Trotter, independent midwife, www.sharontrotter.org.uk