Progesterone, ovulation and birth control?

[sameeralord]

Hello everyone,

I'm slightly confused here. After ovulation, progesterone increases markedly. Now progesterone is also used as a contraceptive for creating a hostile environment for fertilisation and not allowing sperm to enter. So after ovulation how does fertilisation occur normally, if progesterone increases right after that. I see that it takes like 5 days for progesterone to peak. So does fertilisation have to occur before progesterone increases a lot. Also after fertilisation, doesn't the effects of progesterone cause any problems to the fertilized egg. Thanks

 

[VirHop]

Hello everyone,

I'm slightly confused here. After ovulation, progesterone increases markedly. Now progesterone is also used as a contraceptive for creating a hostile environment for fertilisation and not allowing sperm to enter. So after ovulation how does fertilisation occur normally, if progesterone increases right after that. I see that it takes like 5 days for progesterone to peak. So does fertilisation have to occur before progesterone increases a lot. Also after fertilisation, doesn't the effects of progesterone cause any problems to the fertilized egg. Thanks

Progesterone is different from the progestins used in birth control. Progestins are man-made compounds with some progesterone-like actions. Progesterone is a distinct molecule made by the ovary in the luteal phase of the menstrual cycle. The fetus is also bathed in progesterone during pregnancy.

Progestins suppress ovulation and thin the lining of the endometrium which prevents implantation of an egg, and when they are discontinued the lining sheds in a pseudo-menstruation (pseudo because there is no ovum).

When an ovary releases an egg, the corpus luteum releases progesterone, and this stops the other ovary from releasing an egg. In theory, if progesterone was used prior to ovulation, it would block ovulation because both ovaries would have received a signal that the other one had ovulated.

Virginia Hopkins

 

[sameeralord]

Progesterone is different from the progestins used in birth control. Progestins are man-made compounds with some progesterone-like actions. Progesterone is a distinct molecule made by the ovary in the luteal phase of the menstrual cycle. The fetus is also bathed in progesterone during pregnancy.

Progestins suppress ovulation and thin the lining of the endometrium which prevents implantation of an egg, and when they are discontinued the lining sheds in a pseudo-menstruation (pseudo because there is no ovum).

When an ovary releases an egg, the corpus luteum releases progesterone, and this stops the other ovary from releasing an egg. In theory, if progesterone was used prior to ovulation, it would block ovulation because both ovaries would have received a signal that the other one had ovulated.

Virginia Hopkins

Thanks for the reply . Your answer is very good but I still have some questions. Is the main difference between progestin and progesterone is that, progestin prevents implantation and progesterone promotes it by creating a secretory phase. If the answer for this is Yes, I have understood it.

 

[VirHop]

There are many kinds of progestins, so it's hard to say that there's a main difference between progestins in general and progesterone in particular. Some progestins have androgen-like effects, others have cortisol-like effects, one even behaves like the drug spironolactone, which is a diuretic and anti-androgen.

Progestins are truly Frankenstein-like molecules. You could just as easily compare some of them to testosterone or cortisol as to progesterone.

If the progestins are blocking ovulation, there wouldn't even be an egg to implant. Furthermore, if the withdrawal of the progestin at the end of the cycle causes the endometrial lining to shed, it wouldn't matter if an egg was implanted -- it's leaving with the endometrial lining.

 

[sameeralord]

There are many kinds of progestins, so it's hard to say that there's a main difference between progestins in general and progesterone in particular. Some progestins have androgen-like effects, others have cortisol-like effects, one even behaves like the drug spironolactone, which is a diuretic and anti-androgen.

Progestins are truly Frankenstein-like molecules. You could just as easily compare some of them to testosterone or cortisol as to progesterone.

If the progestins are blocking ovulation, there wouldn't even be an egg to implant. Furthermore, if the withdrawal of the progestin at the end of the cycle causes the endometrial lining to shed, it wouldn't matter if an egg was implanted -- it's leaving with the endometrial lining.

Thanks again for the reply I understand how progestin can stop the LH surge and block ovulation but I'm confused with this sentence "Progestins suppress ovulation and thin the lining of the endometrium which prevents implantation of an egg,"

Now if I assume this is also done by progesterone. Now after an implantation or pregnany , progesterone level in the body is increased. So if progesterone "thins the lining of the endometrium which prevents implantation of an egg", whjy wouldn't the implanted egg fall off.