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Meta-Analysis
. 2022 Feb 11:12:814648.
doi: 10.3389/fendo.2021.814648. eCollection 2021.

The Effect of Endometrial Thickness on Pregnancy, Maternal, and Perinatal Outcomes of Women in Fresh Cycles After IVF/ICSI: A Systematic Review and Meta-Analysis

Zhiqi Liao  1 , Chang Liu  2 , Lei Cai  1 , Lin Shen  1 , Cong Sui  1 , Hanwang Zhang  1 , Kun Qian  1
Affiliations
Meta-Analysis

The Effect of Endometrial Thickness on Pregnancy, Maternal, and Perinatal Outcomes of Women in Fresh Cycles After IVF/ICSI: A Systematic Review and Meta-Analysis

Zhiqi Liao et al. Front Endocrinol (Lausanne). .

Abstract

Background: Thin endometrium on ovulation triggering day is associated with impaired pregnancy outcomes in women after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI), but the role of thick endometrium on pregnancy outcomes remains controversial. Moreover, there has been insufficient evidence currently to analyze the influence of endometrial thickness (EMT) on obstetric complications and perinatal outcomes. Thus, we performed this meta-analysis to evaluate the effect of EMT on pregnancy, maternal, and perinatal outcomes in an enlarged sample size.

Methods: The databases Pubmed, Embase, Cochrane Libraries, and Web of Science were searched for English articles evaluating the correlation between EMT and pregnancy, maternal, or perinatal outcomes in women who underwent IVF/ICSI. We included studies that depicted a clear definition of outcomes and EMT grouping on ovulation triggering day. The EMT effect was analyzed in fresh cycle. Qualities of studies were assessed by the Newcastle-Ottawa Scale (NOS). Odds ratios (ORs) and weighted mean difference (WMD) with 95% confidence intervals (CIs) were calculated for analyzing dichotomous and continuous outcomes respectively, under a fixed or random effect model.

Results: A total of 22 pieces of literature were included for the final meta-analysis. A decreased trend towards pregnancy outcomes was observed, such as live birth rate (LBR), clinical pregnancy rate (CPR), and implantation rate (IR) in the thin endometrium groups (EMT <7 mm). In contrast, thick endometrium (EMT >14 mm) had no effect on pregnancy outcomes compared to medium EMT groups (EMT 7-14 mm). Moreover, thin endometrium (EMT <7.5 mm) enhanced the incidence of hypertensive disorders of pregnancy (HDP) and small-for-gestational-age (SGA) infants, and decreased the birthweight (BW) of babies.

Conclusions: Our studies indicated that thin endometrium not only had detrimental effect on pregnancy outcomes, but also increased the risk of HDP in women and SGA of babies, or decreased BW of babies. The thick endometrium does not have an adverse effect on IVF outcomes. Therefore, patients need to be informed on possible obstetric complications and perinatal outcomes caused by thin endometrium and are encouraged to actively cooperate with perinatal care.

Systematic review registration: (https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=242637), identifier CRD42021242637.

Keywords: endometrium; in vitro fertilization; intracytoplasmic sperm injection; pregnancy complications; pregnancy rate.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Flow chart of searching and screening strategy.
Figure 2
Figure 2
Comparison of LBR between EMT groups in fresh cycles. (A) Comparison between thin endometrium group and non-thin endometrium group. (B) Comparison between thick endometrium group and medium endometrium. LBR, Live birth rate; EMT, Endometrial thickness.
Figure 3
Figure 3
Comparison of CPR between EMT groups in fresh cycles. (A) Comparison between thin endometrium group and non-thin endometrium group. (B) Comparison between thick endometrium group and medium endometrium. CPR, Clinical pregnancy rate; COH, Controlled ovarian hyperstimulation; NC, Natural cycles.
Figure 4
Figure 4
Comparison of IR between EMT groups in fresh cycles. (A) Comparison between thin endometrium group and non-thin endometrium group. (B) Comparison between thick endometrium group and medium endometrium. IR, Implantation rate.
Figure 5
Figure 5
Comparison of MR between EMT groups in fresh cycles. (A) Comparison between thin endometrium group and non-thin endometrium group. (B) Comparison between thick endometrium group and medium endometrium. MR, Miscarriage rate; EMR, Early miscarriage rate.
Figure 6
Figure 6
Comparison of maternal outcomes between EMT <7.5 mm and EMT >7.5 mm in fresh cycles. (A) Comparison of PP between thin endometrium group and non-thin endometrium group. (B) Comparison of PA between thin endometrium group and non-thin endometrium group. (C) Comparison of HDP between thin endometrium group and non-thin endometrium group. PP, Placenta previa; PA, Placenta abruption; HDP, hypertensive disorders of pregnancy.
Figure 7
Figure 7
Comparison of perinatal outcomes between EMT <7.5 mm and EMT >7.5 mm in fresh cycles. (A) Comparison of SGA between thin endometrium group and non-thin endometrium group. (B) Comparison of BW between thin endometrium group and non-thin endometrium group. (C) Comparison of LGA between thin endometrium group and non-thin endometrium group. (D) Comparison of PTD between thin endometrium group and non-thin endometrium group. SGA, Small-for-gestational-age; BW, Birthweight; LGA, Large-for-gestational-age; PTD, Preterm delivery.
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References

    1. Farquhar C, Marjoribanks J. Assisted Reproductive Technology: An Overview of Cochrane Reviews. Cochrane Database Syst Rev (2018) 8. doi: 10.1002/14651858.CD010537.pub5 - DOI - PMC - PubMed
    1. Vaegter KK, Lakic TG, Olovsson M, Berglund L, Brodin T, Holte J. Which Factors Are Most Predictive for Live Birth After In Vitro Fertilization and Intracytoplasmic Sperm Injection (IVF/ICSI) Treatments? Analysis of 100 Prospectively Recorded Variables in 8,400 IVF/ICSI Single-Embryo Transfers. Fertil Steril (2017) 107:641–8.e2. doi: 10.1016/j.fertnstert.2016.12.005 - DOI - PubMed
    1. Basir GS, WS O, So WWK, Ng EHY, Ho PC. Evaluation of Cycle-to-Cycle Variation of Endometrial Responsiveness Using Transvaginal Sonography in Women Undergoing Assisted Reproduction. Ultrasound Obstetr Gynecol (2002) 19:484–9. doi: 10.1046/j.1469-0705.2002.00685.x - DOI - PubMed
    1. Fang R, Cai L, Xiong F, Chen J, Yang W, Zhao X. The Effect of Endometrial Thickness on the Day of Hcg Administration on Pregnancy Outcome in the First Fresh IVF/ICSI Cycle. Gynecol Endocrinol (2016) 32:473–6. doi: 10.3109/09513590.2015.1132304 - DOI - PubMed
    1. Eftekhar M, Mehrjardi SZ, Molaei B, Taheri F, Mangoli E. The Correlation Between Endometrial Thickness and Pregnancy Outcomes in Fresh ART Cycles With Different Age Groups: A Retrospective Study. Middle East Fertil Soc J (2019) 24:16–20. doi: 10.1186/s43043-019-0013-y - DOI

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