Systematic meta-analysis of subsequent pregnancy outcomes in recurrent pregnancy loss couples with parental abnormal chromosomal karyotype

Background: Parental abnormal chromosomal karyotypes are considered as reasons for recurrent pregnancy loss. Objective This systematic meta-analysis evaluated the current evidence on pregnancy outcomes amongst couples with abnormal versus normal chromosomal karyotypes. Search strategy Two independent reviewers screened titles and abstracts identified in EMBASE and PubMed from inception to January 2021. Selection criteria Studies were included if they provided a description of pregnancy outcomes of parental chromosomal abnormality. Data collection and analysis Random effects meta-analysis was used to compare odds of pregnancy outcomes associated with noncarriers and carriers. Main results A significantly lower first pregnancy live birth rate (FPLBR) was found in carriers than in noncarriers with RPL (OR: 0.55; 95% CI: 0.46-0.65; p<0.00001). Regarding FPLBR between translocation or inversion carriers and noncarriers, a markedly decreased FPLBR was found in translocation (OR: 0.44; 95% CI: 0.31–0.61; p<0.00001) but not inversion carriers. The accumulated live birth rate (ALBR) (OR: 0.96; 95% CI: 0.90–1.03; p=0.26) was similar, while the miscarriage rate (MR) of accumulated pregnancies (OR: 2.21; 95% CI: 1.69–2.89; p<0.00001) was significantly higher in the carriers than in noncarriers with RPL. The ALBR was not significant (OR: 1.82; 95% CI: 0.38–8.71; p=0.45) but the MR (OR: 5.75; 95% CI: 2.57–12.86; p<0.0001) was markedly lower for carriers who choose PGD than natural conception. Conclusions Carriers with RPL had higher risk of miscarriage but obtained a satisfying pregnancy outcome through multiple attempts. No sufficient evidence was found PGD could enhance the ALBR but it was an alternative to decrease the MR.