Fertility charting is a tried and tested way to highlight when a woman’s most (and least) fertile in her cycle. It makes a massive difference to the chances of falling pregnant simply by recording two things across the cycle:
- The basal body temperature (BBT) (the body’s core temperature)
- Changes to the cervix and the mucus it produces
The basal body temperatures (BBT) of women change in response to their sex hormones, and as the sex hormones control the menstrual cycle and ovulation it means a woman’s BBT can predict how likely she is to ovulate and the relative health of her cycle (and the general balance of her body) in other parts of the month too. However a few other things also affect BBTs, especially exercise, illness, alcohol, food and drugs.
The cervix is the opening into the womb, and this ‘gateway’ changes its shape and how it functions in response to changes in the sex hormones. This is an essential part of getting pregnant and it gives us another, almost instant way to track how likely getting pregnant is through the shape and position of the cervix, and the types of mucus it produces.
Improving the chances for a couple trying to conceive has a lot to do with timing sex to the days that have the most chance of conceiving, which sounds pretty simple, but it’s more difficult than imagined! A studyi found most (73%) women who were actively seeking fertility advice couldn’t detect their peak fertility days accurately:
- Despite 64% of the women having seen a MD/GP about their fertility
- And 84% were already using a fertility aid!
- When the women were given accurate aids 91% were pregnant within three cycles
- However each couple had spent an average of $6,637 on fertility testing before this!!ii
Which really brings into focus that even with qualified advice and aids it’s easy for couples to miss optimising their fertility and getting pregnant. Couples trying to conceive are a vulnerable market and some of the advice out there is confusing, contradictory and sometimes plain unhelpful. For some couples it’s not a big deal if they don’t time things perfectly this month and things will probably work out fine next month, but for many couples maximising their chances is crucial. In terms of time, cost and effectiveness, knowing when sex is going to be most successful is key, and fertility charting is more accurate than ovulation predictor tests at showing this.iii
Ovulation predictor kits
|They record the luteinizing hormone (LH) surge but it only lasts for 12-24 hours, so it can be missed||Easy to use and reassuring|
|The LH surge happens about 24 hours before ovulation, but the chances of conceiving are highest 48 hours before ovulation! When kits show positive the chances have already halved…||None of that messing about with thermometers and mucus|
|They put great pressure on couples to have sex at set times, which puts stress on relationships, upsets hormone balance and reduces a man’s ability to perform|
|They record just one thing in the cycle and give no information on how to improve things|
Fertility charting accurately shows the most fertile days of the month, which is crucial for couples who have:
iAccuracy of perception of ovulation day in women trying to conceive, Zinaman M et al. Curr Med Res Opin. 2012 May; 28(5):749-54.
iiMistiming of intercourse as a primary cause of failure to conceive: results of a survey on use of a home-use fertility monitor. Robinson JE, Ellis JE. Curr Med Res Opin. 2007 Feb;23(2):301-6.
iiiDefinition and prevalence of subfertility and infertility C. Gnoth et al. Hum. Reprod. (May 2005) 20 (5): 1144-1147.
ivTime to pregnancy: Results of the German prospective study and impact on the management of infertility, C.Gnoth et al., Human Reproduction Vol.18, No.9 pp. 1959±1966, 2003