LH Surge
The LH surge is the short, sharp rise in luteinizing hormone that triggers the release of an egg. It lasts about a day or two and comes shortly before ovulation. Blood tests and home urine tests can both pick it up.
The surge is useful, and it is also easy to miss. In a multicenter study of 107 women followed over 326 cycles, the luteinizing hormone peak fell within one day of ovulation on ultrasound in 67.6 percent of cycles, while the cervical mucus Peak symptom did so in 74.4 percent.1
Mucus marks a window rather than a single moment. In 108 cycles from 53 women, mucus scores were highest on the day of the surge.2
Cited in this entry
- Ecochard R, Boehringer H, Rabilloud M, Marret H. Chronological aspects of ultrasonic, hormonal, and other indirect indices of ovulation. BJOG : an International Journal of Obstetrics and Gynaecology. 2001. https://pubmed.ncbi.nlm.nih.gov/11510707/
- Fehring RJ. Accuracy of the peak day of cervical mucus as a biological marker of fertility. Contraception. 2002. https://pubmed.ncbi.nlm.nih.gov/12413617/
This content is for educational purposes only and does not constitute medical advice. Consult an RRM clinician or healthcare provider for guidance specific to your situation.