Prenatal Diagnosis Center, Department of Clinical Laboratory, Changning Maternity and Infant Health Hospital, East China Normal University, #786 Yuyuan Road, Shanghai, 200051, China.
Center for Reproductive Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200135, China.
J Assist Reprod Genet. 2021 Apr;38(4):931-939. doi: 10.1007/s10815-021-02082-8. Epub 2021 Jan 26.
Obesity, measured by body mass index (BMI), is implicated in adverse pregnancy outcomes for women seeking in vitro fertilization (IVF) care. However, the shape of the dose-response relationship between BMI and IVF outcomes remains unclear.
We therefore conducted a dose-response meta-analysis using a random effects model to estimate summary relative risk (RR) for clinical pregnancy (CPR), live birth (LBR), and miscarriage risk (MR) after IVF.
A total of 18 cohort-based studies involving 975,889 cycles were included. For each 5-unit increase in BMI, the summary RR was 0.95 (95% CI: 0.94-0.97) for CPR, 0.93 (95% CI: 0.92-0.95) for LBR, and 1.09 (95% CI: 1.05-1.12) for MR. There was evidence of a non-linear association between BMI and CPR (P < 10) with CPR decreasing sharply among obese women (BMI > 30). Non-linear dose-response meta-analysis showed a relatively flat curve over a broad range of BMI from 16 to 30 for LBR (P = 0.0009). In addition, we observed a J-shaped association between BMI and MR (P = 0.006) with the lowest miscarriage risk observed with a BMI of 22-25.
In conclusion, obesity contributed to increased risk of adverse IVF outcomes in a non-linear dose-response manner. More prospective trials in evaluating the effect of body weight control are necessary.
体重指数（BMI）衡量的肥胖与接受体外受精（IVF）治疗的女性不良妊娠结局有关。然而，BMI 与 IVF 结局之间的剂量反应关系的形状仍不清楚。
因此，我们使用随机效应模型进行了剂量反应荟萃分析，以估计 IVF 后临床妊娠（CPR）、活产（LBR）和流产风险（MR）的综合相对风险（RR）。
共纳入了 18 项基于队列的研究，涉及 975889 个周期。BMI 每增加 5 个单位，CPR 的综合 RR 为 0.95（95%CI：0.94-0.97），LBR 为 0.93（95%CI：0.92-0.95），MR 为 1.09（95%CI：1.05-1.12）。BMI 与 CPR 之间存在非线性关联的证据（P<10），肥胖女性（BMI>30）的 CPR 急剧下降。非线性剂量反应荟萃分析显示，LBR 在 BMI 为 16 至 30 的较宽范围内呈相对平坦的曲线（P=0.0009）。此外，我们观察到 BMI 与 MR 之间存在 J 形关联（P=0.006），BMI 为 22-25 时观察到的流产风险最低。
总之，肥胖以非线性剂量反应方式导致不良 IVF 结局的风险增加。需要更多前瞻性试验来评估体重控制的效果。
