The Importance of Progesterone in Pregnancy


For a pregnancy to evolve favorably, many factors come into action and play their role. In cases where assisted reproduction techniques are used, some of these factors are more controlled, but this does not always ensure the desired pregnancy.

The first step that is intended through these techniques is fertilization and the achievement of good-quality embryos. The quality of the eggs and sperm plays a crucial role in this process.

Once fertilization has been achieved and the embryo has formed, evolved to the blastocyst stage (5 days of evolution), the next step to achieve pregnancy is the correct implantation of the embryo, and here there are still variables that can influence the important way in achieving the goal.

At this point, the endometrium must be ideally prepared and receptive so that the embryo can implant, and it is at this point in the process that progesterone plays an important role.

What is progesterone?


Progesterone, along with estrogens, is a fundamental hormone in the sexual sphere of women. Like all sexual hormones, they have a great influence on development during female puberty and are closely related to the reproductive capacity of women. In this case, it is in charge of facilitating the adaptation of the endometrium so that it is prepared to receive the embryo and implant it.

But this is not its only function during pregnancy. It also plays an important role in the rest of the uterine structures and the rest of the pregnant woman’s body, facilitating the body’s adaptation to the needs of the embryo and fetus. It facilitates timely muscle relaxation for the correct evolution at each moment of pregnancy.

In addition to all this, it also helps the immune regulation process, which allows the intrauterine acceptance of the embryo and fetus by the mother. This is another of the changes experienced by the pregnant woman’s body, which prevents the body from rejecting the embryo.

In assisted reproduction, the intervention of progesterone is even more important, as in cases of in vitro fertilization or, above all, in treatments involving the donation of eggs, embryos, or in cases in which it is transferred to a frozen embryo. In these cases, the ovulatory function must be inhibited to avoid interference of the ovarian function itself in the medical preparation of the endometrium, so it is important to administer progesterone in a controlled manner.

The administration of this hormone is usually performed vaginally, for its convenience, economy, and effectiveness. However, in cases where the patient presents vaginal intolerance or another variable that may hinder absorption, subcutaneous administration is chosen.

What progesterone levels are present?

The levels of progesterone considered normal vary depending on the stage of life in which the woman is. The hormone begins to be detected in the preadolescence stage, at which time the female body undergoes more changes because it goes from being a girl to a woman. At this stage, the progesterone index is between 0.07 and 0.52 ng/ml.

When the woman grows and is an adult, the levels rise slightly, reaching values between 0.15 and 0.70 ng/ml. After ovulation, a moment known as the luteal phase, the values rise considerably since the corpus luteum is formed, which is responsible for the creation of progesterone at this time (in cases of pregnancy, the placenta assumes this function from the second trimester). In this phase, the values range between 2 and 25 ng/ml.

If pregnancy is achieved, the values continue to increase progressively. In the first trimester, the indices are between 7.25 and 44 ng/ml, in the second trimester between 19.5 and 82.5 ng/ml, and in the third trimester the highest values can be obtained, between 65 and 229 ng/ml. All these values stabilize again once the pregnancy period is over until reaching the age of menopause, which is below 0.4 ng/ml.

What can cause an alteration of the values?


The values ​​mentioned are those that are considered normal, the levels that we could describe as standard. However, each body works differently, so in cases where some variation is perceived, it is best to consult a specialist. Progesterone values ​​can be obtained quickly and reliably with a blood test.

Normally, when the indices are higher than expected, it is due to the calendar, as a consequence of being in the days after ovulation, or because of a pregnancy. In cases where these two possibilities are ruled out, it may also be due to an ovarian cyst or adrenal hyperplasia, although it is not common, or due to medication.

In cases where the levels are lower than what is established, it may be caused by an ovulation problem, an ectopic pregnancy, or a miscarriage. Correcting the levels is not complicated, you can easily raise the levels with mediation.

An alteration in progesterone levels can cause irregular menstrual periods, fluid retention, mood swings, or headaches before menstruation, among others. In any case, a visit to a specialist will always be the best option to resolve all the doubts that arise and to determine the cause of the alteration.

The role of progesterone is very important in the pregnancy process. As an important female sex hormone, it is decisive in the implantation of the embryo in the endometrium, but it also enables changes in the uterus that are necessary for the pregnancy process to prosper successfully. The levels of this hormone skyrocket after ovulation, and continue to rise if a pregnancy is achieved.

In cases in which pregnancy is sought with assisted reproduction treatment, it is important to have sufficiently high values ​​to avoid problems in the implantation of the embryo on the endometrium. Its vaginal administration is usually easy and direct and, in this way, absorption is facilitated.

As always, if any alteration is perceived or any doubt arises related to progesterone levels, you should visit a specialist to determine the cause and offer guidance on how to act. Want to know more about pregnancy? We suggest you visit and read some articles there.