Allotey et al reported a model for predicting seizures in a pregnant woman with a history of epilepsy. The authors are from multiple institutions in the United Kingdom, the Netherlands and Australia.
Patient selection: pregnant woman with a history of epilepsy
Parameters:
(1) age at first seizure
(2) seizure diagnosis classification at booking
(3) dose of levetiracetam at booking in mg/day
(4) dose of lamotrigine at booking in mg/day
(5) non-tonic clonic seziures 3 months pre-pregnancy
(6) tonic-clonic seizures 3 months pre-pregnancy
(7) admitted to hospital for seizures in previous pregnancy
(8) learning difficulty or mental health disorder
|
Parameter
|
Finding
|
Points from Nomogram
|
Points from Text
|
|
age
|
|
2.8 - (0.07 * (age))
|
-0.02 * (age)
|
|
levetiracetam
|
|
0.0005*(dose)
|
0.02 * (dose)/100
|
|
lamotrigine
|
|
0.01 * (dose)
|
0.29 * (dose)/100
|
|
seizure diagnosis
|
tonic-clonic
|
0
|
1.97
|
|
|
non tonic-clonic
|
2.6
|
0.75
|
|
|
unspecified
|
2.1
|
0.61
|
|
non tonic-clonic seizures at 3 months pre-pregnancy
|
no
|
0
|
0
|
|
|
yes
|
2.3
|
0.66
|
|
tonic-clinic seizures at 3 months pre-pregnancy
|
no
|
0
|
0
|
|
|
yes
|
6.8
|
1.97
|
|
admitted for seizures in previous pregnancy
|
no
|
0
|
0
|
|
|
yes
|
0.6
|
0.17
|
|
learning difficulty or mental health disorder
|
no
|
0
|
0
|
|
|
yes
|
2.3
|
0.67
|
|
constant
|
|
|
-1.39
|
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score from nomogram: 0
• maximum score from nomogra: 29.5
• The higher the score the greater the risk of seizures.
|
Score
|
Risk of Seizures (Nomogram)
|
|
0 to 17.7
|
X = (0.28943 * (score)) - 2.1889
probability = 1/(1+EXP((-1)*X))
|
|
> 17.7
|
> 95%
|
Performance:
• The area under the ROC curve is 0.76 to 0.79.
