Impact of clomiphene citrate during ovarian stimulation on the luteal phase after GnRH agonist trigger

The strength of evidence supporting luteal phase progestogen after assisted reproduction: A systematic review with reference to trial registration and pre-specified endpoints

OBJECTIVE

To measure the potential for outcome switching and selective reporting, in trials of luteal phase progestogen in assisted reproduction.

STUDY DESIGN

Trials identified through Medline and Embase in August 2017 using the MeSH term "assisted reproductive technology, luteal phase support" and associated text words. Randomised controlled trials (RCTs) comparing progestogen of any type, dose, and route of administration, with placebo or no treatment as luteal phase support in subfertile women undergoing in vitro fertilization (IVF) or intrauterine insemination (IUI). Eight trials after IVF and eleven after IUI, involving 1040 and 2764 participants respectively, were included.

RESULTS

None of the eight trials of progestogen therapy after IVF had been registered. Only 5/11 trials of progestogen after IUI had been registered, and only two of these prospectively. One of these had a registered primary outcome of "pregnancy sac plus heartbeat", but reported "pregnancy sac alone"; we judged this as an altered primary outcome. Three other trial had a registered primary outcome of "clinical pregnancy undefined" and reported "intra or extra-uterine pregnancy with a heartbeat"; we judged this alteration as minimal. That trial was negative. Overall, 26 different outcomes had been reported by the various trials. The three outcomes reported most often were pregnancy undefined (9/19), miscarriage (11/19) and clinical pregnancy (9/19). This suggests considerable potential for selective outcome reporting or outcome switching.

CONCLUSION

Apart from one negative trial, none of the evidence on luteal phase progestogen after assisted reproduction comes from prospectively registered trials: a slender reed indeed.

Folic acid supplementation and IVF pregnancy outcome in women with unexplained infertility

Folic acid supplements are commonly used by infertile women which leads to a positive folate status. However, the effect of folic acid supplements on pregnancy outcome in women with unexplained infertility has not been well investigated. This study evaluated folic acid supplement use and folate status in women with unexplained infertility in relation to IVF pregnancy outcome. In addition, use of folic acid supplements and folate status were compared between women with unexplained infertility and fertile, nonpregnant control women. Women with unexplained infertility used significantly more folic acid supplements and had higher median total folic acid intake from supplements compared with fertile control women (both P < 0.001). Women with unexplained infertility also had significantly higher median plasma folate and lower median plasma homocysteine concentrations than fertile women (both P < 0.001), but folic acid supplementation or folate status were not related to pregnancy outcome in women with unexplained infertility. In conclusion, folic acid supplementation or good folate status did not have a positive effect on pregnancy outcome following infertility treatment in women with unexplained infertility. Folate is one of the B vitamins which has been suggested to be related to infertility. Folic acid is an artificial form of folate which is commonly used in dietary supplements. Folic acid supplementation has been shown to increase folate concentrations and decrease concentrations of the amino acid homocysteine in the blood. Folic acid supplementation is commonly used by infertile women, but the effect on pregnancy outcome in women with a diagnosis of unexplained infertility has not been thoroughly investigated. In the present study, folic acid supplement use and folate status (concentrations of folate and homocysteine) in women with unexplained infertility were evaluated in relation to pregnancy outcome. In addition, the use of folic acid supplements and folate status were compared between women with unexplained infertility and fertile control women. Our results showed that women with unexplained infertility used considerably more folic acid supplements and had higher total folic acid intake from supplements compared with fertile control women. Women with unexplained infertility had better blood folate and homocysteine concentrations than fertile women, but folic acid supplementation or folate status were not related to pregnancy outcome following the infertility treatment. In conclusion, high folic acid intake or good folate status did not increase the possibility of a birth of a healthy baby after infertility treatment in women with unexplained infertility.