In recent years, the negative impact of oxidative stress on fertility has become widely recognised. Several studies have demonstrated its negative effect on the number and quality of retrieved oocytes and embryos following in-vitro fertilisation (IVF). Melatonin, a pineal hormone that regulates circadian rhythms, has also been shown to exhibit unique oxygen scavenging abilities. Some studies have suggested a role for melatonin in gamete biology. Clinical studies also suggest that melatonin supplementation in IVF may lead to better pregnancy rates. Here we present a critical review and summary of the current literature and provide suggestions for future well designed clinical trials.Electronic supplementary materialThe online version of this article (doi:10.1186/s13048-014-0098-y) contains supplementary material, which is available to authorized users.

Background For many subfertile women, assisted reproductive techniques (ART) is the only hope for a pregnancy and live birth. The combined oral contraceptive pill (OCP) given prior to the hormone therapy in an IVF cycle may result in better pregnancy outcomes of ART. Objectives To assess whether pre-treatment with combined OCPs, progestogens or estrogens in ovarian stimulation protocols affects outcomes in subfertile couples undergoing ART. Search methods We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, PsycINFO. Other electronic resources on the Internet, reference list of relevant articles were also searched as well as the ESHRE abstracts (2008). All these searches were conducted in November 2008. Selection criteria Randomised controlled trials of pre-treatment with combined OCP, progestogen or estrogen in subfertile women undergoing IVF/ ICSI. Data collection and analysis Two authors independently extracted the data and assessed risk of bias. We calculated Peto odds ratios for dichotomous data and weighted mean difference for continuous variables. Authors of trials were contacted in case of missing data. 1 Oral contraceptive pill, progestogen or estrogen pre-treatment for ovarian stimulation protocols for women undergoing assisted reproductive techniques (Review)

Background For many subfertile women, assisted reproductive techniques (ART) is the only hope for a pregnancy and live birth. The combined oral contraceptive pill (OCP) given prior to the hormone therapy in an IVF cycle may result in better pregnancy outcomes of ART. Objectives To assess whether pre-treatment with combined OCPs, progestogens or estrogens in ovarian stimulation protocols affects outcomes in subfertile couples undergoing ART. Search methods We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, PsycINFO. Other electronic resources on the Internet, reference list of relevant articles were also searched as well as the ESHRE abstracts (2008). All these searches were conducted in November 2008. Selection criteria Randomised controlled trials of pre-treatment with combined OCP, progestogen or estrogen in subfertile women undergoing IVF/ ICSI. Data collection and analysis Two authors independently extracted the data and assessed risk of bias. We calculated Peto odds ratios for dichotomous data and weighted mean difference for continuous variables. Authors of trials were contacted in case of missing data. 1 Oral contraceptive pill, progestogen or estrogen pre-treatment for ovarian stimulation protocols for women undergoing assisted reproductive techniques (Review)