Progesterone, also called progesterone, is a natural progesterone. After pregnancy, the hCG secreted by the embryo stimulates the corpus luteum of the ovaries to produce progesterone; After 10 weeks of pregnancy, the work of synthesizing progesterone is taken over by the placenta.
(1) Progesterone acts on the endometrium, turning it into the baby's favorite soft crib, which helps embryo implantation;
(2) It can also act on the myometrium and inhibit uterine contractions;
(3) It can also promote maternal and fetal immune tolerance at the maternal-fetal interface, so that the baby can grow up steadily.
Do I need to monitor progesterone in the first trimester? Get advice from leading experts in obstetrics, gynecology and reproduction:
"Consensus on luteal support and progesterone supplementation" and "Clinical practice guidelines for progestogen-maintained pregnancy and luteal support": monitoring serum hCG levels to determine pregnancy villi activity is recommended, ultrasound monitoring of embryonic development, and monitoring of serum progesterone levels and their changes is not required.
"Chinese Expert Consensus on the Diagnosis and Treatment of Spontaneous Abortion 2020 Edition": Ultrasonography is the "gold standard" for judging the outcome of early pregnancy. Before 10 weeks of pregnancy, progesterone in the body mostly originates from the secretion of the ovaries, showing pulsar release and large range of variation, and monitoring serum progesterone levels cannot effectively predict pregnancy outcomes.
Progesterone is so important, why doesn't it need to be monitored?
1. Before 10 weeks of pregnancy, progesterone is mainly synthesized by the ovaries, with pulsive release and a large range of mutation, and the value at a certain time cannot accurately reflect the level in the body;
2. If low progesterone is detected after natural pregnancy, it is usually the result of poor embryonic development and miscarriage rather than the cause, and it is difficult to improve the outcome even with exogenous progesterone;
3. Due to ovulation induction drugs and egg retrieval caused by granule cell loss and other reasons, the IVF process is prone to luteal insufficiency, and there will be enough fetal protection drugs to escort everyone, without testing progesterone;
4. Progesterone for vaginal use mainly plays a role in the uterus, the local concentration of the uterus is high, and the serum progesterone level is significantly lower than that of systemic drugs (such as intramuscular injection, oral).
Therefore, what you think of "low progesterone" is probably not really low, and there is no need to monitor serum progesterone in the first trimester, and there is no need to compare with "other people's progesterone".
Who needs progesterone supplementation in the first trimester?
1. Assisted reproductive technology to help pregnancy
The ovulation induction process in IVF inhibits endogenous LH, resulting in luteal insufficiency; When egg retrieval, a large number of granular cells are removed, causing luteal insufficiency; Some transplant cycle preparation protocols do not have follicle development and luteal formation, so women who are assisted by IVF need exogenous progestogens supplementation. In addition, routine ovulation induction guides intercourse and artificial insemination after pregnancy, progesterone supplementation is also required.
2. Threatened abortion and unexplained recurrent miscarriage
Progestogens may be used in patients with threatened miscarriage and unexplained recurrent miscarriage to reduce miscarriage rates and improve pregnancy outcomes.
Author: Wang Yuan, Shanghai Renji Center for Reproductive Medicine