New long-lasting weekly injections of fertility hormones are as safe and effective as standard daily injections, according to Cochrane researchers. The researchers compared weekly and daily hormone injections in a Cochrane systematic review and found no difference in pregnancies or serious side effects between the two regimens.
Women undergoing fertility treatment are usually given daily injections of follicle stimulating hormone (FSH) to increase the number of eggs that their ovaries release each month. In in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI), the eggs are then removed and fertilised outside the body. Daily hormone injections can be painful and stressful but a new longer-lasting FSH, known as corifollitropin alfa, has recently been introduced. One injection of this longer-lasting hormone can replace the first seven days of FSH injections required in the standard treatment regimen.
The researchers included data from four trials involving 2,335 people in their review. They show that women given medium doses of the new long-lasting hormone on a weekly basis are equally likely to become pregnant and are no more likely to have a miscarriage or ectopic pregnancy than those receiving daily FSH injections.
"These results show that the new long-acting injections are a safe treatment option and equally effective in medium doses compared to the standard daily injections," said Jan Kremer, one of the authors of the review based at the Radboud University Nijmegen Medical Center in Nijmegen, Netherlands.
However, there is currently limited information about patient satisfaction with long-lasting FSH. "One of the main reasons weekly injections are considered preferable to daily injections is that they are more patient friendly," said Kremer. "So are couples undergoing fertility treatment happier with weekly injections? We would like to see research addressing this question."
Further research is also needed to establish whether long-acting injections are as effective in women who respond poorly to fertility hormones and those who 'hyperrespond', meaning they produce higher than expected numbers of eggs.
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Pouwer AW, Farquhar C, Kremer JAM. Long-acting FSH versus daily FSH for women undergoing assisted reproduction. Cochrane Database of Systematic Reviews 2012, Issue 6. Art. No.: CD009577. DOI: 10.1002/14651858.CD009577.pub2