What are the reasons for the second line on a pregnancy test strip to appear faint?

Generally, a faint second line on a pregnancy test strip may be caused by late conception, diluted urine, biochemical pregnancy, ovarian pregnancy, polycystic ovary syndrome (PCOS), and other reasons. If discomfort occurs, it is recommended to seek timely medical consultation and treatment at a formal hospital. Detailed explanations are as follows:

1. Late Conception

A long menstrual cycle or delayed ovulation results in fewer actual days of pregnancy, leading to insufficient secretion of human chorionic gonadotropin (hCG) by the embryo, which causes a faint second line on the test. Retesting with morning urine three days later is recommended. During this time, maintain a balanced diet, consume more protein-rich foods, and avoid fatigue.

2. Diluted Urine

Excessive water intake before testing may dilute the hCG concentration in the urine, resulting in a lighter second line on the test. Reduce fluid intake one hour before testing. Morning urine is recommended for testing because it contains a higher concentration of hCG, which increases test accuracy.

3. Biochemical Pregnancy

An embryo fails to implant successfully, causing a temporary rise and then decline in hCG levels. This can lead to a fading second line on the test strip and may be accompanied by vaginal bleeding similar to a menstrual period. No special treatment is required. Rest well, avoid strenuous exercise, change sanitary products frequently during bleeding, maintain external genital hygiene, and consider checking progesterone levels before the next pregnancy attempt.

4. Ovarian Pregnancy

An embryo implants in the ovary, which is a type of ectopic pregnancy. Poor embryonic development leads to low hCG secretion, resulting in a faint second line on the test. It is often accompanied by mild lower abdominal pain. Immediate medical attention is required. Treatment with methotrexate injection should be administered under a doctor's guidance. If ovarian rupture and bleeding occur, laparoscopic surgery may be needed to repair or remove the lesion.

5. Polycystic Ovary Syndrome (PCOS)

Hormonal imbalances affect embryonic development, leading to slow increases in hCG levels and a faint second line on the pregnancy test. Menstrual irregularities may also occur. Under a doctor's guidance, hormonal regulation can be achieved using medications such as progesterone soft capsules, dydrogesterone tablets, and ethinylestradiol cyproterone acetate tablets. At the same time, manage body weight and reduce intake of high-sugar foods.

In daily life, maintain a positive mindset and avoid excessive anxiety; follow a regular routine and avoid staying up late; seek medical attention promptly if experiencing persistent abdominal pain or heavy bleeding; women planning pregnancy can undergo hormone level testing in advance to ensure their bodies are in an optimal condition for conception.