A Dilation and Curettage (D&C) is a common medical procedure often performed after a miscarriage or to terminate a pregnancy. The procedure involves gently opening the cervix and removing tissue from the uterine lining. While a D&C removes the pregnancy-related tissue, the hormonal changes that supported the pregnancy do not reverse immediately. This means that a standard home pregnancy test will likely remain positive for a period of time afterward.
Understanding hCG After a D&C Procedure
The reason a pregnancy test remains positive after a D&C relates directly to the presence of Human Chorionic Gonadotropin (hCG). It is produced by the cells that form the placenta. The primary function of hCG is to signal the body to maintain the uterine lining and support the growing pregnancy.
Home pregnancy tests work by detecting the presence of this hormone in the urine. Even after the pregnancy tissue is removed during the D&C, the circulating hCG does not vanish instantly. The body must metabolize and clear this hormone, a process that takes time.
The level of hCG in the body is directly related to the duration of the pregnancy before the procedure. Since the hormone is cleared through the body’s natural processes, its presence is detectable until it drops below the sensitivity threshold of the test being used. This physiological clearance is why a positive test result immediately following the procedure is expected.
Typical Timeline for a Negative Test Result
The time it takes for a home pregnancy test to become negative after a D&C varies significantly, generally ranging from two to six weeks. The decline of hCG levels follows a predictable pattern, but the starting point is unique to each individual. For a home urine test to register negative, the hCG level must fall below approximately 25 milli-international units per milliliter (mIU/mL), which is the standard sensitivity of most over-the-counter tests.
The clearance process is initially rapid, with hCG levels often dropping by 35% to 50% within the first two days following the procedure. This exponential decline continues, so by about one week post-procedure, the level may have dropped by over 85%. For those who were earlier in their pregnancy, the hormone level may fall below detectable limits within two weeks.
Healthcare providers often use quantitative blood tests to measure the exact amount of hCG in the blood, which is a more precise measurement than a urine test. For a non-pregnant result, the blood level must drop below 5 mIU/mL. The average time to reach this non-pregnant range is approximately 37 days, or about five weeks, after the procedure. It is common for a urine test to show a very faint positive for a week or two after the blood test has already returned to a non-pregnant state.
Key Factors Influencing hCG Clearance Speed
The most significant factor determining the clearance speed is the initial hCG concentration at the time of the D&C. Pregnancies that were further along in gestation, such as those approaching the end of the first trimester, typically had higher peak hCG levels. Conversely, a procedure performed for a very early loss, where the hCG level was still relatively low, will result in a much quicker return to a negative test result.
Another contributing factor is the efficiency of the D&C procedure itself, which should remove all placental tissue. The rate of hCG decline is also influenced by individual metabolic variations, which affect how quickly the body processes and eliminates the hormone. While research suggests the rate of decline itself is fairly consistent, the sheer volume of the hormone present at the start will dictate the total time needed for clearance.
Persistent Positive Results and When to Contact a Doctor
A positive pregnancy test that persists beyond six to eight weeks after a D&C warrants further medical evaluation. The most common reason for a delayed clearance is the presence of Retained Products of Conception (RPOC), which is placental or fetal tissue that remains in the uterus. This tissue continues to produce hCG, preventing the hormone level from dropping back to zero.
A healthcare provider should be consulted immediately if the home test line appears to be getting darker instead of lighter, or if the test remains strongly positive four weeks post-procedure. Other concerning signs include heavy bleeding, fever, or increasing pelvic pain. In rare instances, a persistent or rising hCG level may indicate gestational trophoblastic disease (GTD), which is abnormal growth of placental cells. To investigate a persistent positive result, a doctor will typically order follow-up quantitative blood tests to monitor the exact hCG trend and may perform an ultrasound to check for any remaining tissue.