It is reassuring that your HCG is doubling. Your progesterone level is low for 6 weeks gestation. However, this should not be a problem with adequate treatment. Although some physicians use oral Prometrium in your situation, to my knowledge there have not been any studies that prove that this is an adequate dose. The Pope Paul VI Institute, which has done quite a bit of research on this topic, would recommend a dose of intramuscular injections of 200 mg every 3-4 days. This dose has been studied on large numbers of women. We usually teach the husband to give the woman injections. There is other literature that suggests that progesterone vaginal suppositories 50-100 mg.every twelve hours is sufficient. Oral prometrium is not as reliably absorbed as injections or suppositories.
In my office we order progesterone for intramuscular injection from Kubat pharmacy in Omaha Nebraska. They make a more concentrated injection of 100 mg./ml so that 200 mg can be injected in one injection (rather then two). They will ship it overnight with a docotr’s order. We do not discontinue progesterone until the woman maintains adequate levels on her own, as demonstrated after testing “trough” levels of progesterone after a four day period just before the next injection. Although many physicans believe the placenta always produces adequate progesterone after about eleven weeks, this is not always true; many women benefit from progesterone supplementation beyond this time, sometimes at reduced doses. Progesterone has been shown to prevent mid-trimester pregnancy loss and pre-term labor. A good protocol to use in prescribing progesterone can be obtained from the Pope Paul VI Institute in their recent textbook. It can also be obtained from CANFP for use by your physician.
Dr. Mary Davenport