PrivateFAQPregnancyWhat is lh surge?
A pregnant woman holding her hands around her belly

What is lh surge?

The lh surge is a term used to describe the rise in the hormone called luteinizing hormone and it happens on the 14th day of the menstrual cycle. Once the luteinizing hormone rises, the ovulation is triggered after a period of 36 to 40 hours. After the egg is released, it can live in the uterus for approximately 24 hours. This is also called the “fertile window”, which is the only time during the menstrual cycle where the woman can become pregnant.

During your menstrual cycle the lh surge comes naturally after the 14th day, but if you enter fertility treatment, either with donor sperm or your partners sperm, you will receive a trigger shot, that causes your body to produce the hormone needed to create the lh surge and therefore cause ovulation.

Read more about how ovulation works here.