Pregnancy test identifies the presence of hCG in the urine of the women. The test kit produces color if the hCG is present in the urine. A pregnancy test with molar pregnancy may give a positive pregnancy test.
Will You Get A Positive Pregnancy Test With A Molar Pregnancy?
As the level of hCG is higher in a molar pregnancy, it may lead to a positive pregnancy test. However, in some cases, the test may give false negative results due to an abnormally high level of hCG landing to “high dose hook effect”.
The initial test for the pregnancy is performed by the urine examination through immunoassay system. This is the simplest way to diagnose the pregnancy. As the fertilized ovum attached to the placenta, it starts secreting hCG hormone, the presence of which is been tested by the pregnancy kit. The level of hCG should such that it is identified by the kit. The identifiable level of hCG during pregnancy reaches as early as 6-10 days after conception.
The level above 25 mIU/ml in blood indicates a positive pregnancy while a level below 5 mIU/ml indicates a negative pregnancy. There is a huge difference between the levels of hCG in normal pregnancy and molar pregnancy. In fact, high levels of hCG and snow storm pattern are the markers of gestational trophoblastic disease including molar pregnancy.
Theoretically, it can be concluded that the urine pregnancy test will show positive results in both the cases as urine samples in both conditions contains an adequate amount of hCG hormone. However, there are instances when this theory deviates during actual practice. In some cases of molar pregnancy, the test provides false negative results. This is due to a phenomenon known as ‘high dose hook effect’ as the level of hCG hormone is abnormally high during complete molar pregnancy. In the hook effect abnormally large quantity of antigen blocks the solid as well as the other phase of antibody. This does not allow forming a sandwich which is responsible for the formation of color. This results in false negative identification of hCG hormone. This can be reduced by diluting the urine thereby reducing the concentration of hCG.
However, it should be noted that high levels of hCG may also be due to other serious conditions such as cancer and other gestational trophoblast diseases. Further, all the molar pregnancy does not have a high level of hCG hormone while all the pregnancies with a high level of hCG hormone are not molar pregnancy. Some normal pregnancy with high levels of hCG results in a live birth.
The pregnancy test is the simplest test to preliminary diagnoses the presence of pregnancy. This is generally done through pregnancy strips and the test can be done at home. As this test identifies the presence of a particular hormone which is not secreted until implantation takes place. Thus, this test may give false negative results if the test is done during the early days of pregnancy.
The hormone which is identified by the pregnancy strip is human chorionic gonadotrophin hormone (hCG). It should be noted that when the test is done by the clinician, it results in almost 97% accuracy but when the test is done by the consumers, accuracy is significantly reduced.
Uterine Changes In Molar Pregnancy
Various uterine changes, as seen in normal pregnancy, are also revealed in the molar pregnancy along with characteristic features. The molar pregnancy is initially identified with high levels of hCG hormone in blood along with severe vaginal bleeding. The hormone level is more than 100000 mIU/ml. However, this is a preliminary diagnosis as the higher level may also be due to underlying serious disease.
The next stage is diagnosing through imaging technique, which results in the scanning of the uterus from all planes for identifying the characteristic feature. The chorionic villi are seen enlarged in the patients with molar pregnancy along with impaired angiogenesis in trophoblast. The ultrasound also reveals the snowstorm pattern or bunch-of-grapes pattern due to the presence of cysts. Theca lutein cysts are also present in the adnexa due to ovarian hyperstimulation by abnormally high levels of hCG. Cysts are also found in the endometrial cavity.