Controlled ovarian stimulation (COS) is one of the most vital parts of in vitro fertilization-embryo transfer (IVF-ET). At present, no matter what kinds of COS protocols are used, clinicians have to face the challenge of selection of gonadotropin starting dose. Although several nomograms have been developed to calculate the appropriate gonadotropin starting dose in gonadotropin releasing hormone (GnRH) agonist protocol, no nomogram was suitable for GnRH antagonist protocol. This study aimed to develop a predictive nomogram for individualized gonadotropin starting dose in GnRH antagonist protocol. Single-center prospective cohort study was conducted, with 198 women aged 20-45 years underwent IVF/intracytoplasmic sperm injection (ICSI)-ET cycles. Blood samples were collected on the second day of the menstrual cycle. All women received ovarian stimulation using GnRH antagonist protocol. Univariate and multivariate analysis were performed to identify predictive factors of ovarian sensitivity (OS). A nomogram for gonadotropin starting dose was developed based on the multivariate regression model. Validation was performed using concordance statistics and bootstrap resampling. A multivariate regression model based on serum anti-Müllerian hormone (AMH) level, antral follicle count (AFC), and body mass index (BMI) was developed and accounted for 59% of the variability of OS. An easy-to-use predictive nomogram for gonadotropin starting dose was established with excellent accuracy. The concordance index (C-index) of the nomogram was 0.833 (95% CI, 0.829-0.837). Internal validation using bootstrap resampling further showed the good performance of the nomogram. In conclusion, gonadotropin starting dose in antagonist protocol can be predicted precisely by a novel nomogram.

受控卵巢刺激 (COS) 是最重要的部分之一 体外受精-胚胎移植 (IVF-ET)。目前，无论采用何种 COS 方案，临床医生都面临着促性腺激素起始剂量选择的挑战。尽管已经开发了几种列线图来计算促性腺激素释放激素 (GnRH) 激动剂方案中合适的促性腺激素起始剂量，但没有列线图适用于 GnRH 拮抗剂方案。本研究旨在开发 GnRH 拮抗剂方案中个体化促性腺激素起始剂量的预测列线图。进行了单中心前瞻性队列研究，198 名 20-45 岁的女性接受了 IVF/卵胞浆内单精子注射 (ICSI)-ET 周期。在月经周期的第二天收集血液样本。所有女性均使用 GnRH 拮抗剂方案接受卵巢刺激。进行单变量和多变量分析以确定卵巢敏感性（OS）的预测因素。基于多元回归模型开发了促性腺激素起始剂量的列线图。使用一致性统计和自举重采样进行验证。建立了基于血清抗苗勒管激素 (AMH) 水平、窦卵泡计数 (AFC) 和体重指数 (BMI) 的多元回归模型，并解释了 59% 的 OS 变异性。以极好的准确性建立了一个易于使用的促性腺激素起始剂量预测列线图。列线图的一致性指数（C 指数）为 0.833（95% CI，0.829-0.837）。使用自举重采样的内部验证进一步显示了列线图的良好性能。综上所述，