The complete menstrual cycle varies from 25 to 36 days and is made up of three distinct phases, all controlled by different hormones. The increase in luteinizing hormone sends a message to the follicle to release the mature egg into the Fallopian tube.
After release of the egg, the follicle closes and creates a 2- to 5-cm structure called the corpus luteum, which is essential in maintaining pregnancy 2. The corpus luteum secretes the hormones progesterone and estrogen, which prepare the uterus to nourish a fetus 2.
The high levels of estrogen and progesterone also inhibit the production of luteinizing hormone, so an LH surge during pregnancy is not possible. The test will indicate a positive result if the hormone human chorionic gonadotrophin is present in the urine.
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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. When the body’s levels of luteinizing hormone (LH) rise, it triggers the start of ovulation, and the most fertile period of the menstrual cycle occurs.
Tracking the surge in luteinizing hormone levels can help people to plan intercourse and increase the chances of becoming pregnant. Understanding what LH is, when levels of the hormone rise, and the relationship between this increase and fertility can be important for women trying to get pregnant.
In this article, we describe methods of tracking, how long surges last, and how to use them to increase the odds of pregnancy. However, around the middle of the cycle, when the developing egg reaches a certain size, LH levels surge to become very high.
Because the period of fertility is so short, it is important to keep track of it when trying to conceive, and noting the timing of the LHsurgecan help. It is best to start testing levels when the fertile window is drawing near, or a handful of days before ovulation.
LH levels in the urine the number of days since the last menstrual period the consistency of the cervical mucus LH levels drop after ovulation, so the tests only show positive results during fertile periods.
If a person has irregular cycles, testing can be difficult, expensive, frustrating, and unreliable. Women with polycystic ovary syndrome (PCs) may experience persistently high LH levels, and tests may show positive results throughout their cycles.
Women approaching menopause may also have elevated LH levels, which makes test results unreliable. If a person tests too late in their cycle, they will miss the LH surge and have to wait until the next month.
If it takes a long time to conceive, buying multiple Oaks can get expensive. A doctor can also identify the fertile period by examining the ovaries on a transvaginal ultrasound scan.
A person can figure out the timing of the LH surge with an OPK or by taking a blood test. When you first started thinking about having a baby, the phrase LH surge probably didn’t cross your mind.
But if you’re trying to get pregnant, you’ve probably developed a sudden new interest in monitoring the level of luteinizing hormone (LH) in your urine. 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 LHsurgecan 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.
The image below represents what different LH patterns would look like on daily LH tests from cycle day 11 through cycle day 21 according to the results of the study: 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.
Any medical information is strictly my opinion based on research and personal experience, and not to be taken as advice. Always seek the advice of a licensed physician for your medical needs.
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. First, buy an OPK (I recommend this one– –from Amazon, as it’s cheap and pairs with the free Premium app).
The app will let you take a picture of your test strip and analyze it for you! A positive result means you’re about to ovulate, which is when your most fertile time is.
Here are some issues, possible complications + FAQs that I had to do a little research to figure out: 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.