Abstract：
OBJECTIVE: The M6 prediction model stratifies the risk of development of ectopic pregnancy (EP) for women with pregnancy of unknown location (PUL) into low risk or high risk, using human chorionic gonadotrophin (hCG) and progesterone levels at the initial visit to a gynaecological emergency room and hCG level at 48 h. This study evaluated a second model, the M6NP model, which does not include the progesterone level at the initial visit. The main aim of this study was to validate the diagnostic accuracy of the M6NP model in a population of French women.
METHODS: Between January and December 2021, all women with an hCG measurement from the gynaecological emergency department of a teaching hospital were screened for inclusion in this study. Women with a pregnancy location determined before or at the second visit were excluded. The diagnostic test was based on logistic regression of the M6NP model, with classification into two groups: high risk of EP (≥5%) and low risk of EP (<5%). The reference test was the final outcome based on clinical, biological and sonographic results: failed PUL (FPUL), intrauterine pregnancy (IUP) or EP. Diagnostic performance for risk prediction of EP, and also IUP and FPUL, was calculated.
RESULTS: In total, 759 women with possible PUL were identified. After screening, 341 women with PUL were included in the main analysis. Of these, 186 (54.5%) were classified as low risk, including three (1.6%) with a final outcome of EP. The remaining 155 women with PUL were classified as high risk, of whom 60 (38.7%), 66 (42.8%) and 29 (18.7%) had a final outcome of FPUL, IUP and EP, respectively. Of the 32 women with PUL with a final outcome of EP, 29 (90.6%) were classified as high risk and three (9.4%) were classified as low risk. Therefore, the performance of the M6NP model to predict EP had a negative predictive value of 98.4%, a positive predictive value of 18.7%, sensitivity of 90.6% and specificity of 59.2%. If the prediction model had been used, it is estimated that 4.5 visits per patient could have been prevented.
CONCLUSIONS: The M6NP model could be used safely in the French population for risk stratification of PUL. Its use in clinical practice should result in a substantial reduction in the number of visits to a gynaecological emergency room.
METHODS: Between January and December 2021, all women with an hCG measurement from the gynaecological emergency department of a teaching hospital were screened for inclusion in this study. Women with a pregnancy location determined before or at the second visit were excluded. The diagnostic test was based on logistic regression of the M6NP model, with classification into two groups: high risk of EP (≥5%) and low risk of EP (<5%). The reference test was the final outcome based on clinical, biological and sonographic results: failed PUL (FPUL), intrauterine pregnancy (IUP) or EP. Diagnostic performance for risk prediction of EP, and also IUP and FPUL, was calculated.
RESULTS: In total, 759 women with possible PUL were identified. After screening, 341 women with PUL were included in the main analysis. Of these, 186 (54.5%) were classified as low risk, including three (1.6%) with a final outcome of EP. The remaining 155 women with PUL were classified as high risk, of whom 60 (38.7%), 66 (42.8%) and 29 (18.7%) had a final outcome of FPUL, IUP and EP, respectively. Of the 32 women with PUL with a final outcome of EP, 29 (90.6%) were classified as high risk and three (9.4%) were classified as low risk. Therefore, the performance of the M6NP model to predict EP had a negative predictive value of 98.4%, a positive predictive value of 18.7%, sensitivity of 90.6% and specificity of 59.2%. If the prediction model had been used, it is estimated that 4.5 visits per patient could have been prevented.
CONCLUSIONS: The M6NP model could be used safely in the French population for risk stratification of PUL. Its use in clinical practice should result in a substantial reduction in the number of visits to a gynaecological emergency room.
摘要：
目的：M6预测模型将不明部位妊娠（PUL）妇女发生异位妊娠（EP）的风险分为低风险或高风险，使用人类绒毛膜促性腺激素（hCG）和孕酮水平在初次访问妇科急诊室和hCG水平在48小时这项研究评估了第二个模型，M6NP模型，其中不包括初次就诊时的孕酮水平。这项研究的主要目的是验证M6NP模型在法国女性人群中的诊断准确性。
方法：在2021年1月至12月之间，对来自教学医院妇科急诊科的所有进行hCG测量的女性进行了筛查，以纳入本研究。排除在第二次访视之前或在第二次访视时确定妊娠位置的妇女。诊断检验基于M6NP模型的逻辑回归，分为两组：EP高风险（≥5％）和EP低风险（<5％）。参考测试是基于临床的最终结果，生物学和超声检查结果：失败的PUL（FPUL），宫内妊娠（IUP）或EP。EP风险预测的诊断性能，还有IUP和FPUL，已计算。
结果：总计，确定了759名可能患有PUL的妇女。筛选后,341名患有PUL的女性被纳入主要分析。其中,186（54.5%）被归类为低风险，包括三个（1.6％），最终结果为EP。其余155名患有PUL的女性被归类为高风险，其中60人(38.7%)，66（42.8％）和29（18.7％）的最终结果为FPUL，IUP和EP,分别。在32名患有PUL且最终结果为EP的女性中，29人（90.6%）被归类为高风险，3人（9.4%）被归类为低风险。因此,M6NP模型预测EP的表现为98.4%的负预测值，阳性预测值为18.7%，敏感性为90.6%,特异性为59.2%。如果使用了预测模型，据估计,每位患者可避免4.5次就诊.
结论：M6NP模型可安全地用于法国人群的PUL危险分层。它在临床实践中的使用应大大减少妇科急诊室的就诊次数。
方法：在2021年1月至12月之间，对来自教学医院妇科急诊科的所有进行hCG测量的女性进行了筛查，以纳入本研究。排除在第二次访视之前或在第二次访视时确定妊娠位置的妇女。诊断检验基于M6NP模型的逻辑回归，分为两组：EP高风险（≥5％）和EP低风险（<5％）。参考测试是基于临床的最终结果，生物学和超声检查结果：失败的PUL（FPUL），宫内妊娠（IUP）或EP。EP风险预测的诊断性能，还有IUP和FPUL，已计算。
结果：总计，确定了759名可能患有PUL的妇女。筛选后,341名患有PUL的女性被纳入主要分析。其中,186（54.5%）被归类为低风险，包括三个（1.6％），最终结果为EP。其余155名患有PUL的女性被归类为高风险，其中60人(38.7%)，66（42.8％）和29（18.7％）的最终结果为FPUL，IUP和EP,分别。在32名患有PUL且最终结果为EP的女性中，29人（90.6%）被归类为高风险，3人（9.4%）被归类为低风险。因此,M6NP模型预测EP的表现为98.4%的负预测值，阳性预测值为18.7%，敏感性为90.6%,特异性为59.2%。如果使用了预测模型，据估计,每位患者可避免4.5次就诊.
结论：M6NP模型可安全地用于法国人群的PUL危险分层。它在临床实践中的使用应大大减少妇科急诊室的就诊次数。
