LH is a hormone produced by your pituitary gland that triggers ovulation. But once the egg in your ovaries reaches a certain stage of development, LH levels increase rapidly.
Since levels of LH spike about 24 hours before ovulation, tracking your LH surge can help you determine when your chances for pregnancy are highest. If you wait for your LH surge to start having sex, you could be missing out on some of the best days of your cycle to conceive.
These tests read a positive result when the level of LH in your urine is above a certain threshold. If you start taking LH tests several days before you expect to ovulate, the idea is that you will “catch” your surge with enough time to have sex during your peak level of fertility.
A 2018 paper called into question the practice of using LH tests to predict peak fertility. The paper argued that the duration of the LH surge varies substantially both within and between women.
This means that a single positive LH test doesn’t tell you that you are going to ovulate in 24 hours. If you’re one of these women, a positive ovulation test doesn’t necessarily mean that you are fertile at all.
A study in the journal Fertility and Sterility looked at how long the LH surge lasts in normally ovulating women. But there are signs and symptoms of ovulation that you can track in order to determine when you ovulate.
Estrogen levels begin to rise roughly 5 days before ovulation. Rising estrogen levels cause your vaginal discharge (also known as cervical mucus) to increase and become more slippery.
This means that you should notice increased fertile vaginal discharge around the time of the LH surge. PCs: This (and other hormonal conditions) can cause elevated LH levels throughout the menstrual cycle Humanized unruptured follicle (LUF): even though hormone levels leading up to ovulation are normal, the follicle doesn’t rupture, so the egg is never released.
In normal menstrual cycles, the ruptured follicle becomes a corpus luteum, which releases progesterone and stimulates the lining of the uterus to build up. But it is known that long term use of anti-inflammatory drugs can prevent the follicle from bursting, sometimes leading to LUF.
If you’re taking anti-inflammatory drugs for chronic conditions like autoimmune diseases, arthritis, or endometriosis you may want to talk to your doctor about possible impacts on your fertility. Roughly 24 – 36 hours before ovulation, LH levels begin to surge to a peak of 25 – 40 mid/ml.
By Lindsay Basel | Published Apr 3, 2017| Last updated Dec 10, 2019 Fact checkedMedically reviewed by Rachel Liberty, RN on December 10, 2019 If you buy through links on this page, we may earn a small commission.
Progesterone is a hormone needed to support a potential pregnancy. If pregnancy doesn’t occur, the corpus luteum shrivels up, stopping the secretion of progesterone, and triggering the start of a menstrual period.
Your LH surge is important because it initiates the beginning of ovulation and your fertile period. For many women, it’s easy to detect their LH surge using ovulation predictor kits (Oaks).
These kits are similar to pregnancy tests because they measure hormone levels in your urine. Each kit is a little different in how they register a positive result, so make sure to check the instructions.
A positive result indicates the presence of a high amount of LH, or your LH surge. The amount of LH in your body will begin to decrease after ovulation, so you’ll only get a positive result during that crucial fertile period.
So knowing how long your cycle is (from one period to the next) will help you figure out when to start testing. This is to make sure that you catch the positive result, in case you have a shorter cycle that month.
Women with the condition polycystic ovary syndrome (PCs) might not be able to use these tests. Some women with PCs have persistently elevated levels of LH, which would lead to an OPK always displaying a positive result, regardless of where you are in your cycle.
Women approaching menopause may also have persistently elevated LH levels. If you start testing too late into your cycle, you may miss the LH surge and won’t get a positive result that month.
If you have trouble using an OPK, you can ask your doctor to run some blood tests to help you pinpoint your ovulation. Usually, a gynecologist or reproductive endocrinologist (infertility specialist) can help you interpret the blood testing results.
If you’ve been using these kits and haven’t become pregnant after six months (if you’re over 35) to a year (if you’re under 35), make an appointment with your doctor. Anonymous patient There are three things necessary to get pregnant: an egg from the female (the product of ovulation), sperm from the male (the product of ejaculation), and an open passage from the uterus to the tubes for the two to meet.
If the patient has been trying for at least six months (preferably 12) and there is no pregnancy, or if there appears to be an obvious problem with one or more of the three factors mentioned above, then she should see a fertility specialist. Dr. Michael Weber Answers represent the opinions of our medical experts.
Any medical information is strictly my opinion based on research and personal experience, and not to be taken as advice. There are several ways to determine when you ovulate (including observing your cervical fluid, charting your temperature, and using an ovulation predictor kit).
Although observing your cervical fluid and charting your temperature are arguably the MOST reliable methods of tracking ovulation (according to my go-to book for all things' fertility, Taking Charge of Your Fertility), I’m personally a fan of Oaks (even though I was very hesitant to try them at first!). Using an ovulation predictor kit is easy, fairly unambiguous, cheap, and reliable (unless you have an LH surge but don’t actually ovulate …which is possible, as you’ll see below, but still not super likely).
Ovulation predictor strips test the level of LH (luteinizing hormone) in your urine. The LH surge (rise) occurs right before you ovulate, so using these strips will tell you when the best time is to have sex in order to maximize your chances of getting pregnant.
A positive result means you’re about to ovulate, which is when your most fertile time is. For some people, the LH surge lasts less than 10 hours…so let’s say you test at 10am one day and 10am the next day… you may have missed it.
If you see that the test line is beginning to get a little darker (onset of the surge), that doesn’t necessarily mean you will ovulate 35-44 hours later. Just in case you’re wondering: In that same study, the onset of the LH surge usually happened between midnight and 4am (37%) or 4am and 8am (48%).
Soon….the first time you see the line begin to get darker, that’s the onset of the LH surge, but it likely actually happened between midnight and 8am of that day. As you use these things, you’ll figure out your LH surge and how long it typically lasts for you.
When you are trying to conceive, one thing you will surely want to know is the best time for intercourse on the purpose of impregnation. In terms of fertility and paternity, the release process can be called LH surge.
Getting clear about the relations between the LH surge and ovulation can be essential in your conception process. The LH surge is essentially a signal sent from the brain to the ovary, indicating that an egg is mature.
Any detection of a burst in the release of luteinizing hormone is an indication of the onset of ovulation. The ovulation predictor kit takes effect by detecting the LH hormone or LH surge.
These test kits are typically performed on a daily basis, around the time ovulation is expected to occur. The tests can be read manually via paper strips telling results by color changing, or using digital electronic device.
If the reading changes from negative to positive, then it would suggest that ovulation is due to take place within 48 hours, meaning that there is a 2-day window in which to perform sexual intercourse or artificial insemination. As the LH surge usually happens after the start of the fertile window, LH tests are generally not suggestible for contraceptive practices.
The LH surge just give reliable signals about the peak fertile days that you can try to conceive with high chances. On average, the majority of women will experience an LH surge by 8 a.m., yet it generally takes around 4 hours for the surge to be detectable when testing.
An ovulation predictor kit can be used at noon or so during this time, and mostly it will yield positive results. For women who have irregular cycles, the results of ovulation testing kits will consistently be inconsistent; meaning a consultation with a physician may be required.
It is the unfortunate actuality that 10% of women will find the use of ovulation predictor kits ineffective, meaning that they will require help from a physician to determine their fertile window. Ovulation prediction kits are extremely easy to use and require no special knowledge or expertise.
If injectable fertility drugs are present within a person's system, such as Personal, the kits will often not function effectively or with reliability. For women over 40, especially those reaching the age of menopause, the tests are invalid as they will always have increased levels of luteinizing hormone in their systems.