Stock et al reported a model for predicting preterm birth following preterm labor symptoms. The authors are from multiple institutions in the United Kingdom and the Netherlands.
Patient selection: pregnant woman with preterm labor symptoms (back pain, abdominal cramping, abdominal pain, light vaginal bleeding, vaginal pressure, uterine tightening, uterine contractions)
Gestational range: 22/0 to 34/6 weeks
Parameters:
(1) fetal fibronectin (ffN) in vaginal fluid in ng/mL
(2) smoking
(3) ethnicity
(4) nulliparity
(5) multiple pregnancy
transformed fetal fibronectin =
= (((measured ffN) + 1) /100)^0.5
|
Parameter
|
Finding
|
Points
|
|
fetal fibronectin
|
|
1.915 * (transformed ffN)
|
|
smoking
|
no
|
0
|
|
|
yes
|
-0.687
|
|
ethnicity
|
White
|
0
|
|
|
other
|
-0.139
|
|
nulliparity
|
no
|
0
|
|
|
yes
|
0.370
|
|
multiple pregnancy
|
no
|
0
|
|
|
yes
|
0.834
|
value of X =
= SUM(points for all of the parameters) - 5.263
probability of spontaneous preterm labor within 7 days =
= 1 / (1 + EXP((-1) * X))
Performance:
• The area under the ROC curve is 0.89.
