van der Steeg J W, Steures P, Eijkemans M J C, Habbema J D F, Hompes P G A, Broekmans F J, van Dessel H J H M, Bossuyt P M M, van der Veen F, Mol B W J
Department of Public Health, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
Hum Reprod. 2007 Feb;22(2):536-42. doi: 10.1093/humrep/del378. Epub 2006 Sep 22.
Prediction models for spontaneous pregnancy may be useful tools to select subfertile couples that have good fertility prospects and should therefore be counselled for expectant management. We assessed the accuracy of a recently published prediction model for spontaneous pregnancy in a large prospective validation study.
In 38 centres, we studied a consecutive cohort of subfertile couples, referred for an infertility work-up. Patients had a regular menstrual cycle, patent tubes and a total motile sperm count (TMC) >3 x 10(6). After the infertility work-up had been completed, we used a prediction model to calculate the chance of a spontaneous ongoing pregnancy (www.freya.nl/probability.php). The primary end-point was time until the occurrence of a spontaneous ongoing pregnancy within 1 year. The performance of the pregnancy prediction model was assessed with calibration, which is the comparison of predicted and observed ongoing pregnancy rates for groups of patients and discrimination.
We included 3021 couples of whom 543 (18%) had a spontaneous ongoing pregnancy, 57 (2%) a non-successful pregnancy, 1316 (44%) started treatment, 825 (27%) neither started treatment nor became pregnant and 280 (9%) were lost to follow-up. Calibration of the prediction model was almost perfect. In the 977 couples (32%) with a calculated probability between 30 and 40%, the observed cumulative pregnancy rate at 12 months was 30%, and in 611 couples (20%) with a probability of >or=40%, this was 46%. The discriminative capacity was similar to the one in which the model was developed (c-statistic 0.59).
As the chance of a spontaneous ongoing pregnancy among subfertile couples can be accurately calculated, this prediction model can be used as an essential tool for clinical decision-making and in counselling patients. The use of the prediction model may help to prevent unnecessary treatment.
自然妊娠预测模型可能是筛选具有良好生育前景的亚生育夫妇的有用工具，因此应对这些夫妇进行期待管理咨询。我们在一项大型前瞻性验证研究中评估了最近发表的自然妊娠预测模型的准确性。
在38个中心，我们研究了连续入选的因不孕症检查而转诊的亚生育夫妇队列。患者月经周期规律，输卵管通畅，总活动精子数（TMC）>3×10⁶。不孕症检查完成后，我们使用一个预测模型来计算自然持续妊娠的几率（www.freya.nl/probability.php）。主要终点是1年内自然持续妊娠发生的时间。通过校准评估妊娠预测模型的性能，校准是指对患者组预测和观察到的持续妊娠率进行比较以及鉴别能力评估。
我们纳入了3021对夫妇，其中543对（18%）自然持续妊娠，57对（2%）妊娠未成功，1316对（44%）开始治疗，825对（27%）既未开始治疗也未妊娠，280对（9%）失访。预测模型的校准几乎完美。在计算概率为30%至40%的977对夫妇（32%）中，12个月时观察到的累积妊娠率为30%；在计算概率≥40%的611对夫妇（20%）中，这一比例为46%。鉴别能力与模型开发时相似（c统计量为0.59）。
由于可以准确计算亚生育夫妇自然持续妊娠的几率，该预测模型可作为临床决策和咨询患者的重要工具。使用该预测模型可能有助于避免不必要的治疗。
