Many couples experiencing infertility and who want to get pregnant can undergo various treatments to help them conceive. Scientists and physicians have designed treatment methods that give couples the best chance of success. One technique of inducing ovulation is by injecting the HCG hormone. Hopeful potential parents might want to take a pregnancy test soon after treatments, but receiving an HCG injection can affect the results and can provide an incorrect answer.
Ovulation
Ovulation is the beginning of the process leading to pregnancy. Each ovary contains follicles, which are compartments that hold an egg. Prior to ovulation, the pituitary gland produces follicle stimulating hormone, which causes the follicles to develop, preparing for release of the egg. This process occurs about once a month for women of child-bearing age, causing a monthly menstrual period if pregnancy does not occur. For women experiencing infertility, medications might be used to stimulate ovulation.
HCG
Human chorionic gonadotropin is a hormone produced by the body during pregnancy. During the initial weeks after pregnancy occurs, HCG is produced by the placenta as a method of supporting the fetus. Its levels rise during the first 14 weeks of pregnancy, after which it tapers off. For this reason, testing for HCG levels is a sign of pregnancy. During infertility treatments, a single dose of HCG can be given as an injection just before ovulation occurs. This is known as a “trigger” shot because the hormone triggers ovulation to occur about 36 hours later.
Significance
If a pregnancy occurs, a fertilized egg will implant in the uterus, and HCG is produced. Pregnancy tests work by detecting the amount of HCG in the body. With home pregnancy tests, this is done by checking levels in the urine, which simply shows if HCG is present or not. A doctor’s office can do a blood test to determine specific levels of HCG, which will indicate pregnancy. Blood HCG levels in a pregnant woman should increase every day.
Benefits
Many women who are trying to get pregnant are eager to take a test as early as possible. For some women going through infertility treatments, they likely have waited a long time to see a positive result. According to the University of Michigan Health System, after the placenta begins releasing HCG, it can be detected in the blood as soon as six days after the embryo implants in the uterus. HCG levels may also be in the urine during this time, which is why some home pregnancy tests can be taken before a missed menstrual period.
Considerations
Eleven to 12 days after ovulation, a blood test can be done to confirm pregnancy after an HCG shot. This is called measuring the quantitative HCG, which is more accurate than a home test. Early testing might need to be repeated, and quantitative testing should be done at least two times to ensure that levels stem from pregnancy and are not related to the HCG shot.
