By Deborah Brauser
ATLANTA -- October 27, 2009 -- A treatment with low-dose metformin improves pregnancy rates in patients who have repeatedly failed to conceive with in vitro fertilisation (IVF), according to results from 2 studies presented here at the 65th Annual Meeting of the American Society for Reproductive Medicine (ASRM).
Masao Jinno, MD, Women's Clinic Jinno, Choufu City, Tokyo, Japan, presented the results of both studies on October 21. The studies enrolled women without polycystic ovary syndrome (PCOS) undergoing IVF. These women had all had at least 2 failed IVF procedures.
In the first study, 33 patients received metformin 550 mg daily for 8-12 weeks before and during ovarian stimulation for IVF. The outcomes were then compared with those found in the patients' previous IVF procedures and those from control patients matched by age, body mass index, and previous IVF failures. Based on 9 insulin-resistance-related parameters, the investigators then developed a discriminant score (DS) of 0.6647 to predict ongoing pregnancy success. They found that the ongoing pregnancy rate was significantly higher in the metformin-treated group than in the matched control group (30% vs 6.1%, in 33 cycles) or previous IVF data (1.9%, in 104 cycles).
Using the optimal threshold point from the DS, the researchers predicted ongoing pregnancy in the patients treated with metformin with 0.90 sensitivity and 0.91 specificity. This group also had significantly improved follicular development and embryo quality.
In the second study, 199 women were randomised into 4 groups: those treated with metformin who had a DS above (group 1, n = 18) and below (group 2, n = 80) the optimal 0.6647 point and those not treated with metformin but with scores above (group 3, n = 15) and below (group 4, n = 86) the set point. Group 1 had a significantly higher rate of ongoing pregnancy: 56% versus 14%, 20%, and 15% for groups 2 through 4, respectively.
"In summary, low-dose metformin improves the pregnancy rate in IVF repeaters, probably by decreasing insulin resistance. Plus, its indication can be decided by a DS calculated from 9 insulin-resistance-related parameters before metformin administration," reported Dr. Jinno.
"To my knowledge, this is the first report that shows the effectiveness of metformin treatment for non-PCOS patients," said Dr. Jinno. He added, "Metformin can help 20% of IVF patients with repeated failures and without PCOS. These patients are more commonly seen in clinical practice than PCOS patients, so the results are practically very useful."
[Presentation title: Low-Dose Metformin Improves Pregnancy Rate in ART Repeaters Without Polycystic Ovary Syndrome: Its Mechanism and Indication. Abstract P-533]
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