Many women (including myself, I admit) scour their BBT charts for early pregnancy or implantation signs. One of the more commonly looked for implantation signs is an implantation dip. But is an "implantation dip" a real sign of an embryos implantation? Is it a genuine sign of early pregnancy during the two-week wait?
What Is an Implantation Dip?
As you may remember, ovulation can be detected on a basal body temperature chart by a slight shift in temperature mid-cycle. For more about basal body temperature chart, read this step-by-step piece on how to chart your body basal temperature and how to detect ovulation with a BBT chart.
An implantation dip is a one-day drop in temperature on a basal body temperature chart, occurring about one week after ovulation. The dip appears during the luteal phase, the time between ovulation and your expected period. Implantation of the embryo usually occurs between days 7 and 11 of the luteal phase, and this is why some people attribute this sudden one-day dip in temperature to implantation.
The dip in temperature may just be slightly lower than the rest of the post-ovulation temperatures, or it may even dip below the “cover line” on a fertility chart. (The cover line is an arbitrary line that the temperatures on average were below before ovulation, but appear on average above after ovulation.)
Does an Implantation Dip Mean You Are Pregnant?
FertilityFriend.com, a free fertility charting online software company, did an informal analysis of the BBT charts on their site, to see if an implantation dip might indicate pregnancy. This was by no means a scientific study, but the results are still interesting to consider.
They did a statistical analysis of just over 100,000 BBT charts, of both pregnant and non-pregnant women. They looked for a dip in temperature of at least 0.3 F, occurring between days 5 and 12 of the luteal phase.
They found that 11% of BBT charts that detected ovulation and had an implantation dip did not result in pregnancy. On the other hand, they found that 23% of the charts that detected ovulation and did show this implantation dip did result in pregnancy.
The interesting thing to me is that on average, couples have about a 25% chance of getting pregnant in any month. So while it’s true that a greater percentage of charts with the dip resulted in pregnancy, it’s also true that 75% overall did not result in pregnancy. This is what you would expect if you took a random group of couples on any given month, implantation signs or not.
I actually get a small “dip” on my chart almost every month on day 7 or 8 post-ovulation, and I know other women who also show “implantation dips” on their charts month after month – but they are not pregnant.
The funniest thing about implantation dips? The one month I was charting and did get pregnant, I actually did not show an implantation dip.
The Bottom Line
Unfortunately, having an implantation dip is not a reliable sign of pregnancy. Women can have the so-called implantation dip when they are not pregnant, and plenty of women who are pregnant do not show an implantation dip on their BBT chart.
You can still have fun looking for an “implantation dip” – but there’s no reason to get your hopes up if you have one, or feel disappointed if you don’t.
Source:
Is There a Such Thing as an Implantation Dip? FertilityFriend.com. Accessed on January 1, 2009. http://www.fertilityfriend.com/Faqs/Implantation-dip-study.html
