Why does the HCG value appear low while the test strip shows one dark line and one light line?

Jan 21, 2025 Source: Cainiu Health

Dr. Zhang Lu

Introduction

When human chorionic gonadotropin (hCG) levels are low, a pregnancy test strip may show one dark line and one faint line, which could be related to early pregnancy, improper use of the test strip, poor embryonic development, biochemical pregnancy, or ectopic pregnancy. In early pregnancy, this is considered a normal presentation and may not require special intervention. If the test strip was used improperly, retesting is necessary. For pathological causes, timely targeted treatment is required.

Generally, HCG refers to human chorionic gonadotropin. When the level of human chorionic gonadotropin is low, a pregnancy test strip may display one dark line and one light line, which could be related to early pregnancy, improper use of test strips, poor embryonic development, biochemical pregnancy, ectopic pregnancy, and other factors. Timely treatment based on the underlying cause is recommended. If in doubt, it is advisable to seek medical attention promptly. Detailed analysis is as follows:

1. Early Pregnancy

In early pregnancy, due to the short implantation time of the fertilized egg, the level of human chorionic gonadotropin in the urine has not yet doubled. Therefore, this situation may occur. It is a normal phenomenon and generally does not require special treatment.

2. Improper Use of Test Strips

If the test strip is used incorrectly, for example, with insufficient contact time or highly diluted urine, the test result may be affected, leading to a false negative result. It is recommended to retest with a new strip, ensuring proper operation.

3. Poor Embryonic Development

Poor embryonic development is usually associated with maternal malnutrition during pregnancy, drug side effects, and other factors. Restricted embryonic development may lead to low levels of human chorionic gonadotropin, resulting in one dark and one light line on the test strip. This condition can be managed by increasing dietary nutrition. If abnormalities are detected, termination of pregnancy may be considered.

4. Biochemical Pregnancy

Biochemical pregnancy is typically related to maternal or embryonic factors. When the fertilized egg fails to implant normally and miscarriage occurs, the above symptoms may appear. It may be accompanied by abnormal vaginal bleeding and abdominal pain. Timely examination for incomplete miscarriage is necessary, along with proper daily care, such as maintaining hygiene and a balanced diet.

5. Ectopic Pregnancy

Ectopic pregnancy is usually associated with intrauterine infection, contraceptive failure, and other factors. When the embryo implants outside the uterus, a test strip may show one dark and one light line, and human chorionic gonadotropin levels may remain low. It is often accompanied by abdominal pain and vaginal bleeding. Treatment may include medications such as methotrexate injection, mifepristone tablets, and misoprostol tablets, as directed by a physician.

It is recommended to promptly choose an appropriate course of action based on individual circumstances and causes to avoid delaying treatment. During treatment, maintaining an optimistic mindset and avoiding excessive anxiety is also important.

View All

What does it mean if no gestational sac is seen on B-ultrasound examination?

A B-ultrasound examination failing to detect a gestational sac may indicate technical limitations, an examination performed too early, delayed embryonic development, ectopic pregnancy, or maternal conditions such as uterine fibroids. The absence of a gestational sac on B-ultrasound does not necessarily mean pregnancy failure; a comprehensive assessment combining serum hCG levels, clinical symptoms, and follow-up results is necessary. If there are no abnormalities such as abdominal pain or bleeding after the examination, a follow-up check may be scheduled after an interval as directed by a physician.

View Full Answer

What to do if a pregnancy results in a biochemical pregnancy

Under normal circumstances, a biochemical pregnancy, also known as biochemical miscarriage, is a type of early natural abortion. Most cases do not require special treatment, but scientific management is needed to promote recovery. Common management approaches include timely examination, monitoring changes in blood HCG levels, paying attention to rest and bleeding care, adjusting diet and emotional well-being, and investigating causes of recurrent biochemical pregnancies.

View Full Answer

What does it mean when HCG levels are higher than expected for the gestational age?

In general, higher-than-expected HCG levels for gestational age may be caused by errors in estimating gestational age, twin or multiple pregnancies, molar pregnancy, gestational diabetes, or ovarian theca-lutein cysts. If any discomfort occurs, it is recommended to seek timely medical evaluation and treatment at a正规 hospital. In daily life, keeping a record of menstrual cycles can help accurately estimate gestational age, and maintaining a balanced diet during pregnancy is important.

View Full Answer

At what time of day is the HCG level highest?

From the perspective of HCG secretion mechanism, it is continuously secreted by placental trophoblastic cells, and the secretion process is relatively stable, without significant peak variations according to circadian rhythms as seen with certain other hormones. During daytime, when the body is active and metabolism functions normally, HCG levels remain relatively stable, with minimal variation in test results at different times, making it difficult to identify a single peak time.