A pregnancy test is a popular tool that allows you to dispel doubts and determine if a woman is pregnant. The use of the test is indicated when the first signs of conception are detected, including a delay in menstruation.
Tests to establish or exclude pregnancy are of two types: the first is a kit for home use, which can be found in pharmacies and done at home using morning urine; the second is a blood test conducted in the laboratory and necessary to reliably confirm the result.
In both cases, the presence of human chorionic gonadotropin ( beta-hCG ), a hormone secreted in the mother's body during pregnancy, is verified. In fact, beta-hCG can be detected in urine or blood about a week after conception (which, however, occurs within 24 hours of ovulation). Human chorionic gonadotropin is produced by those pre-embryonic cells that will then give rise to the placenta after implantation of a fertilized egg in the uterus. In fact, beta-hCG ensures the preservation of pregnancy in an environment most suitable for the development of the embryo.
A home-use urinalysis gives a qualitative answer (i.e., shows whether you are pregnant or not), and a blood test also allows a quantitative assessment, as it accurately indicates the concentration of the hormone present at the time of the analysis. For this reason, with a positive home pregnancy test result, it is advisable to confirm the result with a blood test for a 100% sure diagnosis and make an appointment with a gynecologist.
Urine and blood pregnancy tests are highly reliable, however, to obtain a safe result, it is recommended to respect the time indicated for each method. As mentioned above, the synthesis of beta-hCG begins when a fertilized egg is implanted in the uterus, i.e. about a week after conception.
Once beta-hCG secretion begins , the concentration of the hormone doubles every two days and peaks 60–70 days after fertilization, then decreases and remains at a minimum level until the end of pregnancy. This means that it can be detected with a pregnancy test before a woman can confirm a missed period.
When can pregnancy start?
Conception occurs when sperm travel up the uterus to reach a mature egg, which is released from the ovary into the fallopian tube at the time of ovulation. The fertilized egg is transported by the movement of the hair cells of the fallopian tube in the direction the phenomenon of the uterine cavity, where it is pressed against the endometrium approximately 6-7 days after intercourse, which led to fertilization (thus, approximately on the 21st day of pregnancy). 28-day regular menstrual cycle).
The period in which fertilization of the egg is possible begins 4-5 days before ovulation and ends 1-2 days after it. This is possible given the fact that a mature egg, when it is expelled from the ovary, manages to survive for about 24 hours, while spermatozoa can remain viable in the female reproductive apparatus for up to 72-96 hours. Therefore, unprotected intercourse even 3-4 days before ovulation can lead to fertilization.
When to take a pregnancy test? If a woman has a regular cycle of 28 days, a home pregnancy test can be done from the first day of a missed period, i.e. approximately 7 days after the implantation of a fertilized egg and 14 days after the intended conception.
It is useless to take a pregnancy test the day after unprotected intercourse, as it takes several days for the body to produce beta-hCG , even if the egg has already been fertilized. If there is a strong suspicion of pregnancy after risky sexual intercourse, a test can be performed approximately 5-7 days before the estimated date on which menstruation is expected to begin. However, in this situation, in order to obtain a certain result, it is recommended to repeat the test after a few days. If the test result is negative, but the delay in menstruation continues, you can contact the Bogolyuby Medical Center for a hematological examination.
