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Meta-Analysis
. 2020 Jul 31;99(31):e21006.
doi: 10.1097/MD.0000000000021006.

Comparison of clomiphene and letrozole for superovulation in patients with unexplained infertility undergoing intrauterine insemination: A systematic review and meta-analysis

Fei Qin  1 , Yanqiong Zhou  1 , Lu Huan  2 , Wenwu Gui  1
Affiliations
Meta-Analysis

Comparison of clomiphene and letrozole for superovulation in patients with unexplained infertility undergoing intrauterine insemination: A systematic review and meta-analysis

Fei Qin et al. Medicine (Baltimore). .

Abstract

Background: With the medical advancement some studies put forward that letrozole (LE), a specific aromatase inhibitor with the function of reducing oestrogen synthesis, has recently been applied as a potentially better alternative compared with clomiphene citrate (CC), owing to that it has a superior efficacy as compared with CC in patients of unexplained infertility undergoing intrauterine insemination (IUI). However, there is no one study can clear and definite whether LE can replace the CC as first line drug.

Objective: Our objective is to compare the LE with CC in the induction of ovulation in patients with unexplained infertility IUI.

Method: Searching databases consist of all kinds of searching tools, such as Medline, The Cochrane Library, Embase, PubMed, etc. All the include studies should meet our demand of this meta-analysis: RESULT:: Based on the current meta-analysis, we rigorously consider that LE has a likelihood to improve dominant follicles (MD= -0.56, I= 100%, P= .04; MD= -0.39, I= 73%, P = .0003, respectively) and reduces the miscarriage rate (RR= 0.61, I= 0%, P = .03). There is no significant differences between the 2 groups in The total rate of pregnancy, pregnancy rate per cycle, multiple pregnancy and endometrial thickness. (RR= 1.06, I= 11%, P = .38; RR= 1.09, I= 7%, P = .32; RR= 0.79, I= 0%, P = .46; respectively) CONCLUSION:: Combined with the results of current systematic review and meta-analysis through subgroup analysis and sensitivity analysis, we can be cautious: in general, compared with CC, LE is an effective treatment in the IUI cycle, has a likelihood to improve dominant follicles and reduces the miscarriage rate.

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Conflict of interest statement

The authors have no funding and conflicts of interest to disclose.

Figures

Figure 1
Figure 1
Flow diagram showing the selection of including studies.
Figure 2
Figure 2
Risk bias of graph. Each risk of bias item presented as percentages across all of the included trials, which indicated the proportion of different level risk of bias for each item.
Figure 3
Figure 3
Risk bias of summary. Judgments about each risk of bias item for each included trials. Green indicates low risk of bias. Yellow indicates unclear risk of bias. Red indicates high risk of bias.
Figure 4
Figure 4
Forest plots of the total rate of pregnancy in infertility patients with LE versus those with CC administration.
Figure 5
Figure 5
Forest plots of pregnancy rate per cycle suggested there was no significant difference between the LE group and CC group.
Figure 6
Figure 6
Patients receiving LE were more likely to Total number of dominant follicles than those with CC administration.
Figure 7
Figure 7
Forest plots of multiple pregnancy in infertility patients with LE vs those with CC administration and there was no significant difference between the 2 groups.
Figure 8
Figure 8
The result of this Forest plots showed that LE could reduce the miscarriage rate.
Figure 9
Figure 9
There was no difference in endometrial thickness for the infertility patients.
See this image and copyright information in PMC

References

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    1. Arici A, Byrd W, Bradshaw K, et al. Evaluation of clomiphene citrate and human chorionic gonadotropin treatment: a prospective, randomized, crossover study during intrauterine insemination cycles. Fertil Steril 1994;61:314–8. - PubMed
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