Table 3.
Results of multivariable logistic regression analysis showing variables independently associated with complete miscarriage ≤ 10 and ≤ 17 days in women with embryonic or anembryonic miscarriage managed expectantly
| Model with crown-rump-length | Model with miscarriage type | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| AUC (95% CI) | Constant | Coefficient | Odds ratio (95% CI) | P valuea | AUC | Constant | Coefficient | Odds ratio (95% CI) | P valuea | |
| Complete miscarriage ≤ 10 days (n = 79) | ||||||||||
| 0.764 | − 3.691 | 0.739 | − 5.058 | |||||||
| (0.659–0.869) | (0.628–0.850) | |||||||||
| Variables in model | ||||||||||
| Gestational age according to last menstrual period (OR for change in days) | 0.08 | 1.083 (1.023–1.146) | 0.003 | 0.083 | 1.087 (1.024–1.153) | 0.002 | ||||
| Mean sac diameter (OR for change in mm) | − 0.146 | 0.864 (0.788–0.948) | 0.001 | − 0.099 | 0.905 (0.838–0.978) | 0.007 | ||||
| CRL (OR for change in mm) | 0.202 | 1.224 (1.086–1.380) | 0 | NA | NA | NA | ||||
| Type of miscarriage (embryonic or anembryonic) | NA | NA | NA | 1.737 | 5.682 (1.724–18.730) | 0.002 | ||||
| Complete miscarriage ≤ 17 days (n = 79) | ||||||||||
| 0.763 | − 3.382 | 0.754 | − 4.783 | |||||||
| (0.658–0.869) | (0.645–0.863) | |||||||||
| Variables in model | ||||||||||
| Gestational age according to last menstrual period (OR for change in days) | 0.07 | 1.072 (1.015–1.133) | 0.008 | 0.076 | 1.079 (1.017–1.144) | 0.006 | ||||
| Mean sac diameter (OR for change in mm) | − 0.111 | 0.895 (0.818–0.979) | 0.01 | − 0.076 | 0.927 (0.858–1.001) | 0.046 | ||||
| CRL (OR for change in mm) | 0.194 | 1.214 (1.074–1.372) | 0 | NA | NA | NA | ||||
| Type of miscarriage (embryonic or anembryonic) | NA | NA | NA | 1.802 | 6.060 (1.837–19.992) | 0.001 | ||||
The probability of treatment success is calculated as [ez/(1 + ez) where e = 2.718 (base value of natural logarithm) and z is calculated as:
z = constant + (coefficient × gestational age according to last menstrual period in days + coefficient × crown-rump length in mm + coefficient × mean sac diameter in mm)
or
z = constant + (coefficient × gestational age according to last menstrual period in days + coefficient × type of miscarriage where anembryonic gestation is coded as 0 and fetal demise as 1 + coefficient × mean sac diameter in mm)
AUC area under receiver-operating characteristic curve, CI confidence interval, OR odds ratio, CRL crown-rump-length, NA not applicable
aLikelihood ratio test