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Trying for a baby should be an enjoyable experience for both with plenty of sex and the prospect of a bundle of joy at the end but sadly it is often not the case. With many western families becoming smaller in the number of children and infertility on the rise, there’s no wonder why the joy is slowly being ebbed away.
To help couples achieve their dream of having a baby there are many tools and data couples can use the optimise conception, from tracking periods, eating healthier and of course tracking ovulation which includes keeping a basal body temperature chart.
What is basal body temperature and how does it link with pregnancy tests?
Basal body temperature (BBT) is your body’s natural temperature when you’re rested and not suffering from any illnesses or not ovulating or pregnant. During a menstrual cycle, a woman’s basal body temperature can range quite a bit between as it goes through all of the phases – menstruation, follicular, proliferative, ovulation, luteal phase and secretory phase.
The reason why temperature shift signifies something for woman trying to conceive is because a rise in temperature can signal ovulation has started and the optimal window of impregnation has begun. For women who did not become pregnant a temperature drop will happen so that the menstrual cycle can begin again, for those who DID become pregnant the temperature will stay high.
And this is why a temp dip is of interest to those trying to get pregnant.
However, there is a strange occurrence which can happen to both pregnant and non pregnant women and it’s called an ‘implantation dip’, which can make BBT charts more hassle than they’re worth.
The implantation dip and why it doesn’t mean you are or aren’t pregnant
This is a BBT chart of a woman who did not end up getting pregnant. It shows a rise then a dip appears and then the temperature rises once more before the period cycle repeats. The first and second rise show the fertility window. Following ovulation the temperature rises again but a sharp drop happens at the end of one cycle and the beginning of the next.
Your body temperature changes slightly throughout the menstrual cycle but rises sharply as it approaches and during ovulation. This is caused by the many hormones released by your body such as progesterone. This rise is completely normal and is one of the things people attribute and link to ovulation and the fertile days.
…and then sudden a one day temperature drop happens before you enter the luteal phase. Many people understand that being pregnant means a higher basal body temperature, your body is super busy after all, so a dip is something that they don’t want to see on their pregnancy BBT charts because it might mean that you’re not pregnant..or does it?
No, it does not.
Statistical analysis shows that there is a temperature drop just after ovulation whether you’re pregnant or not. Every women’s BBT chart varies and even the ones we’ve used as examples should be referred as a guide only.
This body temperature readings graph shows the BBT changes which DID lead to a successful pregnancy – this chart also shows a one day drop in temperature before a further rise after implantation. The temperature drops meant nothing but it still occurred.
Both women had a rise after the dropping temperature but the giveaway for conception here is that the rise after the drop was much higher after conception and then it remained high as it enters the triphasic phase.
Is a BBT drop a sign of failed conception?
A one day change in your post ovulation temperatures should be expected and it’s neither a sign of pregnancy or a sign of a failed one. It is something that just happens to all women with healthy cycles. However, following this one day drop your basal body temperature should rise again as the endometrial lining loosens or significantly rise if the egg as been fertilised.
As all women are different it won’t happen exactly the same as another, but a sustained drop in BBT after ovulation is a sign that pregnancy is unlikely. A sustained drop would be over 2 or more days but this is all informal analysis – nothing will be more conclusive than an actual pregnancy test with a big fat positive.
What happens after the dip is what’s most important
Women should anticipate a slightly lower temperature during the ovulation period for one day or so but it’s what happens after that which matters. Following the implantation dip, your body’s temperature should rise whether or not you’re pregnant but for women who ARE pregnant the rise will be much sharper and higher than any other reading taking during that period.
However, at the end of a cycle which didn’t end in pregnancy the temperatures will fall sharply whereas a successfully pregnant woman’s temperature will remain high.
BBT charts are useful for ovulation and not so much conception
Recording your temperature is an easy and cheap way to family planning but it does have its shortfalls beyond the implantation dip. A sharp rise in temperature is a sign of ovulation along with thicker stickier discharge and generally being sexually charged but post ovulation BBT can cause more stress than its worth.
This can help you optimise your time during the ovulation window to maximise your chances, after that window passes BBT can be unreliable when there are other methods out there including the trusty gut instinct, mucus and two clear blue lines.
Your BBT changes all of the time, for example, having a virus or a bug can cause temperatures to go up and down, being stressed can do the same as well as the ambient temperature. Your temperature could rise or fall for any number of reasons and staring at a graph won’t help you find the answers.