Planning your pregnancy
Planning for conception gives you the best chance of a positive result
Planning for a baby is an exciting time, however, it is important that you understand how the female reproductive system works so you can really maximise your chances of getting pregnant naturally.
Each month a couple has around a 20% chance of getting pregnant1. This means that there could be a longer wait than you first thought before getting pregnant. This can potentially be a long and frustrating wait, not knowing if anything is wrong and, in most cases, not getting the information needed.
In this section we will take you back to basics, so you have a full understanding before starting out on your journey.
Knowing when you’re ovulating is key
We do understand a lot about ourselves and our body, for example we are born with a fixed number of eggs we have for life and that fertility declines naturally with age. What we often don´t understand though is our menstrual cycle and the hormones that are responsible for ovulation and a natural conception. Ovulation is when your ovary releases a mature egg. Knowing when you are about to ovulate will improve your chances of a natural pregnancy.
There are only a few days in your cycle when you are most fertile. Monitoring your fertility hormones and understanding this fertile phase can be important to improving your time to pregnancy. Whilst the average cycle length is 28 days, 95% of women fall between 22 and 36 days. 42.5% of these experience cycle length differences greater than 7 days2. Only 30% of women have all their fertile days within the clinical guideline between day 10 and 173. The timing of the fertile window can therefore be highly unpredictable, even if you have regular cycles. This high variability makes it important to understand what is happening in your body.
Ovulation Fast Facts:
- We are born with a fixed number of eggs that we have for life
- Fertility will naturally decline with age
- Knowing when you are about to ovulate will improve your chances of getting pregnant naturally
- There are 4 important hormones in the female reproductive cycle – Follicle Stimulating Hormone (FSH), Oestrogen, Luteinising Hormone (LH) and progesterone
- It is Luteinising Hormone (LH) that is the main hormone involved in ovulation
- The average cycle length is 28 days, however, 95% of these women’s cycles will fall between 22 – 36 days
- Many women will experience irregular cycles and only 30% of women will have their fertile days within the clinical guideline of day 10 – 17.
- This means that the fertile window can be really unpredictable even if you have regular cycles
About Luteinising Hormone (LH)
One of your key fertility hormones is the Luteinising Hormone (LH), which is the most reliable indicator of impending ovulation. LH is present in your body at a certain base level, measured in milli-international units per millilitre (mIU/mL). Just before ovulation there is a rise of LH (called the ‘LH surge’), which can be detected in urine tests and is indicative of imminent ovulation. The LH surge can be quite different from woman to woman, it can vary from twice the base level to as much as 10 times the base level or more. The LH surge triggers ovulation, which usually occurs approximately 24-48 hours later. The day of the LH surge and the day after are your two most fertile days in your cycle. If you have unprotected intercourse within your most fertile days you maximise your chances of becoming pregnant.
LH levels vary from Woman to Woman
Which explains why so many women still have problems identifying their fertile days.
Studies show that there are variations in the range of LH concentrations in women, with many women have an LH base level that is above or below the normal range. There are also huge variations of the individual LH surges and their profiles. 19% have a small LH peak4. The average LH curve profile, which is a flat baseline with a sharp single-LH peak going back to baseline is only observed in 44% of the cycles in normally ovulating women5. Traditional tests only provide qualitative results, i.e. they compare two lines in a urine test or indicate a ‘smiley face’ or ‘no smiley face’ which means that many women would not be able to pick up their LH surge nor their different hormonal profiles, as the threshold of these tests are based on an average woman’s data.
LH Fast Facts
- LH is the most reliable indicator of impending ovulation
- LH is present in your body at a certain baseline level
- Just before ovulation the level of LH increases, this is known as an LH surge
- It is important to understand that the LH surge triggers ovulation, which will then happen approximately 24 – 48 hours later
- The day of the LH surge and the day after are the 2 most fertile days in your cycle
- If you have unprotected intercourse within your most fertile days, you will increase your chances of becoming pregnant.
Finding Your Fertile Phase
Your fertile phase lasts about 6 days and ends on the day of ovulation, taking into account the survival times of both the sperm and the egg 3, 5. Studies show a rapid drop in the likelihood of conception after ovulation, which suggests a short survival time for the mature egg 5. As the day of ovulation can vary from cycle to cycle and is different from woman to woman, accurate information is required to track your fertile days. This can be done by measuring the changes in your fertility hormones.
Need to know:
- The day of ovulation can vary from cycle to cycle and every woman is different
- It is important that you can accurately track your LH so a clear indication of your fertile window can be given
- A woman’s egg can only survive for 12 – 24 hours after ovulation
- Sperm can survive for up to 5 days within the woman’s reproductive tract.
Some helpful tips to get you started:
- Start taking some pre-pregnancy supplements that contain folic acid and vitamin D
- Staying well hydrated will help blood flow to the uterus and ovaries
- Small increases in protein in the diet can help with egg and sperm quality
- Having sex once a day or even once every other day is perfectly fine during the fertile window, remember sperm needs a chance to recoup
- Timing is everything
- Maintain a healthy diet as being overweight or underweight can influence fertility
- Smoking can considerably affect egg and sperm quality.
- S.Juul et al., Regional differences in waiting time to pregnancy: pregnancy-based surveys from Denmark, France, Germany, Italy and Sweden; Human Reproduction vol14 no5: 1250-1254, 1999.
- Fehring et al., Variability in the phases of the menstrual cycle; JOGNN 2006.
- Wilcox et al., Timing of the "fertile window“ in the menstrual cycle: day specific estimates from a prospective study; BMJ Volume 321, 2000.
- Alliende et al., Mean versus individual hormonal profiles in the menstrual cycle; Fertility and Sterility 2002.
- Wilcox et al., Timing of sexual intercourse in relation to ovulation; NEJM 1995.