Apolipoprotein E (Apo E) gene polymorphisms and recurrent pregnancy loss: a meta-analysis.
BACKGROUND
Recently, a relationship between recurrent pregnancy loss (RPL) and Apolipoprotein E (Apo E) gene polymorphisms has been proposed. In order to investigate the real association between Apo E polymorphisms and RPL, our meta-analysis was carried out.


METHODS
We estimated the association with RPL risk under dominant and recessive models, in combination with the OR and RR with a 95% confidence interval (CI), which was used to assess the association between RPL and Apo E polymorphisms.


RESULTS
According to our criterion, there were 6 studies included. The dominant model used the E4/E3 group and the OR was 1.919 (95 %CI: 1.016-3.625, I(2) = 53.8%), the RR was 1.308 (95%Cl: 1.071-1.598) suggesting that carriers of the E4 allele would have a higher risk of causing spontaneous miscarriages. In addition, the OR was 0.727 (95%CI: 0.566-0.932, I(2) = 0.0%) and RR was 0.923 (95%CI: 0.867-0.982) in a fixed model for E3/E3 homozygotes versus other genotypes, suggesting that the Apo E3 polymorphism could be a protective factor. The OR was 1.365 (95% CI: 1.029-1.811, I(2) = 0 .0%) in a fixed model comparing the E2 allele with the E3 allele, suggesting that Apo E2 polymorphisms may contribute to RPL as a risk factor. Furthermore, after conducting sensitivity analysis in the E4/E3 group, the results showed this to be consistent and the OR was 2.249 (95%CI: 1.474-3.431).


CONCLUSIONS
There is a close association between RPL and Apo E gene polymorphisms. For RPL, the Apo E4 polymorphism could be a risk factor, the Apo E3 polymorphism may be a protective factor and the Apo E2 polymorphism may be another potential risk factor.
Guangxi Reproductive Medical Research Center, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, 530021, China.
Jie
J
Li
Yang
Y
Chen
Hongbo
H
Wu
Liuming
L
Li
D000026:Abortion, Habitual / Q000235:genetics*; D001057:Apolipoproteins E / Q000235:genetics*; D005260:Female; D006720:Homozygote; D006801:Humans; D008957:Models, Genetic; D011110:Polymorphism, Genetic; D011247:Pregnancy
D001057:Apolipoproteins E