CPP protocol
Claritin, Pepcid and prednisone for frozen embryo transfer
What is the CPP protocol?
The CPP protocol is a series of three medications taken by mouth.
You may be familiar with Claritin and Pepcid, over-the-counter medications for allergy relief and stomach irritation. They are both histamine receptor blockers: Claritin blocks H1 and Pepcid blocks H2, and together they can switch off part of an immune system reaction. A stronger immune-modulating medication is prednisone. It is prescription-only, as it has a wider range of side effects.
Who may benefit?
The CPP protocol may help patients with recurrent pregnancy loss (RPL) despite the transfer of euploid embryos. RPL is defined as two or more failed clinical pregnancies. Euploid embryos are embryos that have been screened with preimplantation genetic screening (PGS) in a previous fresh IVF/ICSI cycle.
The CPP protocol has not been validated in peer-reviewed studies.
We reserve the CPP protocol for frozen embryo transfer (FET) plans where one or two euploid embryos will be transferred.
Who cannot use it?
Because of the prednisone, the CPP protocol is not suitable for anyone with diabetes.
What are the side effects?
No side effects are routinely expected from Claritin or Pepcid.
Prednisone, however, has health implications when used long term or at high doses, and there is some controversy about its safety in early pregnancy. Like any drug, steroids carry risks. Some studies have shown an association between first-trimester systemic corticosteroid use and oral clefts or decreased birth weight; however, the information is conflicting and likely related to dose. For this reason, we use low doses, stop the medication early in pregnancy, and limit its use to transfer cycles associated with the highest pregnancy rates per transfer.
Avoid caffeine
Please stop all caffeinated products, including coffee, tea and chocolate, one month before your estimated embryo transfer. You will need to avoid caffeine throughout the FET process and the first trimester of pregnancy.
How to take the medications
The medications start two days before your estimated transfer date. Your nurse will give you these instructions again, with specific dates, as part of your FET schedule.
| Medication | Dose | Where to get it |
|---|---|---|
| Claritin | 10 mg by mouth, once a day, starting 2 days before transfer | Over the counter at any pharmacy, with the allergy medications |
| Pepcid | 20 mg by mouth, twice a day, starting 2 days before transfer | Over the counter at any pharmacy, with the stomach medications |
| Prednisone | 10 mg by mouth, once a day, starting 2 days before transfer | Prescription. Your clinical team will provide it once your FET cycle has begun. |
The medications continue unchanged through to your scheduled pregnancy test.
After your pregnancy test
If your test is positive:
- Claritin and Pepcid continue until 12 weeks of pregnancy.
- Prednisone continues at 10 mg daily until the positive test, then drops to 5 mg daily. It is stopped at 7 weeks of pregnancy, after your ultrasound review.
If your test is negative:
- Claritin and Pepcid are both stopped.
- Prednisone is decreased to 5 mg daily for one week, then stopped.