From the Guidelines
Monitoring beta-human chorionic gonadotropin (βhCG) levels following ovulation induction is crucial for confirming pregnancy and assessing its viability, with the first measurement typically performed approximately 14 days after ovulation or timed intercourse/insemination. The role of βhCG in this context is to confirm conception and monitor the health of the pregnancy. According to the study by 1, the timing of insemination is a critical factor in the outcome of IUI, and βhCG injections are often used to trigger ovulation when the dominant follicle reaches a mean diameter of ~18 mm.
Key Considerations
- A positive βhCG result indicates conception has occurred, and serial measurements should be obtained 48-72 hours apart to ensure appropriate doubling time.
- The study 1 suggests that single IUI can be performed any time between 24 and 40 hours after HCG injection without compromising pregnancy rates.
- βhCG monitoring is essential because these hormones are produced by developing placental tissue and provide valuable information about early pregnancy progression before ultrasound visualization is possible.
Clinical Implications
- βhCG levels should be monitored closely after ovulation induction to confirm pregnancy and assess its viability.
- The results of βhCG measurements can help identify potential complications, such as ectopic pregnancy or impending miscarriage, and guide further management.
- The study 1 highlights the importance of timing in IUI, and βhCG monitoring plays a critical role in this process.
From the FDA Drug Label
The action of HCG is virtually identical to that of pituitary LH, although HCG appears to have a small degree of FSH activity as well. It stimulates production of gonadal steroid hormones by stimulating the interstitial cells (Leydig cells) of the testis to produce androgens and the corpus luteum of the ovary to produce progesterone During the normal menstrual cycle, LH participates with FSH in the development and maturation of the normal ovarian follicle, and the mid-cycle LH surge triggers ovulation. HCG can substitute for LH in this function During a normal pregnancy, HCG secreted by the placenta maintains the corpus luteum after LH secretion decreases, supporting continued secretion of estrogen and progesterone and preventing menstruation.
The role of beta human chorionic gonadotropin (beta hCG) following induction of ovulation is to:
- Maintain the corpus luteum
- Support continued secretion of estrogen and progesterone
- Prevent menstruation [ 2 ]
From the Research
Role of Beta Human Chorionic Gonadotropin (beta hCG)
- Beta hCG is used to trigger ovulation in assisted reproductive technologies such as in vitro fertilization (IVF) and gamete intrafallopian transfer (GIFT) 3.
- The administration of human chorionic gonadotropin (HCG) can induce a spontaneous luteinizing hormone (LH) surge in some patients, which may affect the outcome of ovulation induction 3.
- The occurrence of an LH surge after HCG administration can be influenced by the use of luteinizing hormone-releasing hormone (LHRH) agonists, which can inhibit gonadotropin secretion and reduce the likelihood of an LH surge 3.
Effects of HCG Administration
- HCG administration can cause a delayed occurrence of an LH surge, which may impact the timing of ovulation and fertilization 3.
- The use of LHRH agonists, such as leuprolide acetate, can reduce the incidence of LH surges after HCG administration and improve pregnancy rates 3.
- The clinical outcome of ovulation induction with pulsatile gonadotropin-releasing hormone (GnRH) can be determined by the endocrine response, including the occurrence of LH surges and the levels of estradiol and other hormones 4.
Ovulation Induction Protocols
- Different ovulation induction protocols, such as pulsatile GnRH and gonadotropin therapy, can be used to induce ovulation in women with various ovulatory disorders 5, 6, 7, 4.
- The choice of protocol and the dose of gonadot hormones used can affect the likelihood of ovulation, pregnancy, and multiple pregnancies 5, 6, 7, 4.