Are you curious about the journey an egg takes after it becomes fertilized? What about the role hormones play in successful implantation? In this blog post, we’ll learn what egg implantation is, what symptoms to expect when it occurs, and how to determine if you are experiencing implantation issues.
What is Egg Implantation?
When you have intercourse with your partner during your fertile window, there is a chance that sperm will swim their way into the fallopian tube, where an egg is present. But even if an egg is fertilized, pregnancy is not 100% guaranteed. That’s because the fertilized egg has to descend into and attach to the uterus lining.
This process is called implantation. In other words, even if an egg is fertilized by sperm, you won’t become pregnant if it does not implant into the lining of your uterus. Let’s take a closer look. The egg is released from a fluid-filled sac called the follicle during ovulation.
The egg descends down the fallopian tube while the sac it came from the follicle becomes a structure called the corpus luteum. This corpus luteum starts producing progesterone, which thickens the lining of your uterus for a possible pregnancy. Around five to seven days after ovulation, the fertilized egg will begin to implant itself onto this thickened uterine wall.
Symptoms of Implantation and Progesterone Rises
As the embryo implants into the uterine wall, it gently breaks the surface blood vessels where it attaches. This rupture of a small number of blood vessels during implantation gives you the first sign of implantation, light bleeding, or spotting. Some women may also experience slight pain when the blood vessels rupture. Implantation bleeding usually occurs seven to 10 days after ovulation. It differs from your period in that the bleeding is very light.
Typically just a few drops and sometimes cannot be noticed at all. Now let’s talk about progesterone, a vital hormone in conception. After ovulation, progesterone rises gradually. If an egg implants into the uterine wall, the embryo releases HCG, the hormone that pregnancy tests measure. HCG causes a steep rise in progesterone levels.
Women often experience some symptoms from the rise in progesterone after ovulation, but if implantation occurs, the steeper rise in progesterone can cause more intense symptoms. These can include breast tenderness and enlargement, nausea or sensitivity to certain smells, changes in appetite or feeling disgusted by certain foods, bowel changes like constipation and bloating, fatigue, headaches, and mood changes. These symptoms can be difficult to distinguish from typical post-ovulation symptoms. And, of course, some women don’t have any symptoms at all. So relying on symptoms alone is not a reliable way to detect implantation.
Tracking Progesterone Levels for Successful Implantation
So, how can we track progesterone levels? For pregnancy to happen, you need successful ovulation, the egg meeting the sperm, and progesterone levels to rise and remain elevated for long enough after ovulation. Studies show that a level lower than 7.9 nanograms per milliliter in blood, roughly around 10 micrograms per milliliter PdG in urine, is associated with lower pregnancy outcomes six to eight days after ovulation.
That’s where it’s recommended the Inito Fertility Monitor, which measures progesterone levels. Inito detects PdG, the progesterone metabolite in urine, allowing you to chart your hormones in the Inito app easily. Progesterone levels rise after ovulation and should stay elevated six to eight days post-ovulation. If progesterone levels rise to an adequate level yet drop too soon, it can lead to a shortened luteal phase, which can cause conception issues.
Now you know how a fertilized egg becomes implanted in the uterus wall, what symptoms to expect during implantation, and how to track progesterone levels to detect successful implantation. If you are expecting a little one, use the NHS Pregnancy Calculator to know the Due date.