What typically happens to hCG levels in spontaneous abortions?

In the context of spontaneous abortions, human chorionic gonadotropin (hCG) levels typically exhibit a decline over a 48-hour period. When a pregnancy is developing normally, hCG levels rise as the placenta grows and supports the pregnancy. However, in the event of a spontaneous abortion, there is an interruption of this normal process.

As the pregnancy is lost, the production of hCG ceases, leading to a decrease in its levels in the bloodstream. This drop in hCG levels can be an important clinical indicator for healthcare providers when assessing the viability of a pregnancy. Monitoring hCG levels over time can help ascertain whether there has been a complete miscarriage, as levels would not remain stable or increase under these circumstances.

Therefore, the correct answer reflects the physiological response seen in spontaneous abortions, whereby hCG levels show a notable decrease, typically measured over a period of 48 hours.