Is it necessary to have an empty stomach before HCG test in test tube infants?
In the process of IVF treatment, HCG value detection is a very important link. HCG is a hormone secreted by human cells. After implantation of fertilized eggs, its level will rise sharply. By detecting the HCG value, we can determine whether the pregnancy is successful, and help doctors to judge the embryonic development. However, it is a common question whether it is necessary to test the HCG value on an empty stomach. This problem will be described in detail in the following four aspects: accuracy, signal-to-noise ratio, detection time and actual operation.
1、 Accuracy
First, there is no significant difference in the accuracy of HCG between fasting and non fasting tests. HCG is secreted by chorionic tissue and will not be affected by food intake. Therefore, the detection result of HCG value is reliable whether it is empty or not. According to the implementation standard of a regular hospital, the error range of HCG value between fasting and non fasting detection is about 10% under normal circumstances, and it is not necessary to exhaust empty stomach to evaluate the development of embryos.
In addition, if IVF patients need to take related drugs to assist in pregnancy, these drugs often need to be carried out after meals, then fasting testing cannot meet the treatment needs. Therefore, in actual operation, it will not affect the test results to decide whether to need an empty stomach according to the specific situation of the patient.
2、 Signal-to-noise ratio
The research shows that the ratio of signal to noise is higher when HCG value is detected by non fasting sampling than by fasting sampling. This is because the insulin level in the blood is higher when the stomach is not empty. Insulin can stimulate the decomposition of HCG in the body and improve its release rate. Therefore, non fasting sampling can more sensitively detect low concentration HCG values, which improves the detection sensitivity.
However, for IVF patients, their HCG values are often higher than normal. Therefore, even for fasting sampling, the HCG value can be detected within the effective range. Therefore, during the specific operation, doctors will generally judge whether to sample on an empty stomach according to the patient's condition, and comprehensively consider the influence of signal to noise ratio.
3、 Detection time
In IVF patients, HCG testing is usually arranged according to the time after embryo transfer. Generally speaking, the HCG value will be tested twice, the first time is on the 7th day after transplantation, and the second time is on the 14th day. At these two time points, no matter whether the patient is fasting or not, the results of HCG detection will not be significantly different. Therefore, the detection time has no special requirements on whether an empty stomach is required.
It should be noted that patients should stop using any related drugs according to the doctor's requirements before testing the HCG value to ensure the accuracy of the test results. According to the specific regulations of different hospitals, patients may be required not to eat within 6-12 hours before the test. However, this does not mean that an empty stomach is needed, just to avoid the direct impact of food intake on insulin levels.
4、 Actual operation
In practice, whether it is necessary to test the HCG value on an empty stomach depends on the professional judgment of doctors. The doctor will decide whether to have an empty stomach according to the specific conditions of IVF patients and give corresponding instructions. For example, in the implementation standard of a hospital, it is recommended to stop eating for 4 hours before the HCG value test to avoid the impact of food residues on the test results.
In conclusion, there was no significant difference in the accuracy of HCG detection in test tube infants, whether on an empty stomach or not. In practice, the doctor will decide whether to have an empty stomach according to the specific situation of the patient and give corresponding guidance. Therefore, the patient should consult the doctor in time before testing the HCG value, and operate according to the doctor's suggestions to ensure the accuracy of the test results.
