Menstrual disorders and their determinants among women with epilepsy

Figures & data

Table 1 General characteristics of studied women with epilepsy

Variable	N=271
Age (years); mean (SD)	29.6 (7.3)
Age at onset of epilepsy (years); mean (SD)	14.5 (8.5)
Epilepsy type
Generalized	74 (27.3%)
Focal	182 (67.2%)
Combined (generalized and focal)	6 (2.2%)
Unknown	9 (3.3%)
Frequency of seizures
>1 per month	101 (37.3%)
1–12 per year	62 (22.9%)
<1 per year	108 (39.8%)
The most commonly used AEDs (in mono or polytherapy)
Valproate	108 (39.9%)
Levetiracetam	95 (35.1%)
Lamotrigine	73 (26.9%)
Carbamazepine	48 (17.7%)
Topiramate	31 (11.4%)
Oxcarbazepine	26 (9.6%)
Clonazepam	13 (4.8%)
Concomitant disorders
Allergies	23 (8.5%)
Gastrointestinal disorders	8 (3.0%)
Endocrine disorders	32 (11.8%)
Psychiatric disorders	33 (12.2%)
Any concomitant disorder	91 (33.6%)
Chronic use of medications other than AED	78 (28.9%)

Abbreviation: AED, antiepileptic drug.

Table 2 Reproductive health-related measures among studied patients with epilepsy

Variable	N=271
Age at menarche (years); mean (SD)	13.2 (1.7)
Onset of epilepsy before the menarche	104 (38.5%)
Menstrual abnormalities	78 (28.8%)
Polymenorrhea (<21 days)	0
Oligomenorrhea (>35 days)	6 (2.3%)
Amenorrhea	4 (1.5%)
Number of patients with given number of pregnancies
0	181 (66.8%)
1	39 (14.4%)
2	33 (12.2%)
3	11 (4.0%)
4	6 (2.2%)
5	1 (0.4%)
Number of patients with given number of children
0	186 (68.6%)
1	42 (15.5%)
2	35 (12.9%)
3	8 (3.0%)
Vaginal deliveries	74
Cesarean sections	67

Table 3 Comparison of demographic features, characteristics of the epilepsy, and antiepileptic medications between patients with regular and irregular menstrual cycle among studied patients with epilepsy

Variable	Patients with menstrual abnormalities (n=78)	Patients without menstrual abnormalities (n=193)	P-value
Age (years); mean (SD)	28.2 (6.6)	30.1 (7.5)	0.051
Age at onset of epilepsy (years); mean (SD)	11.6 (7.5)	15.6 (8.6)	<0.001
Age at menarche (years); mean (SD)	12.9 (1.6)	13.3 (1.7)	0.06
Onset of epilepsy before the menarche	40 (51.9%)	64 (33.2%)	0.006
Epilepsy type
Generalized	17 (21.8%)	57 (29.5%)	0.19
Focal	53 (67.9%)	129 (66.8%)	0.86
Combined (generalized and focal)	6 (7.7%)	0	<0.001
Unknown	2 (2.6%)	7 (3.6%)	0.49
Frequency of seizures
> 1 per month	35 (44.9%)	66 (34.2%)	0.10
1-12 per year	20 (25.6%)	42 (21.8%)	0.49
< 1 per year	23 (29.5%)	85 (44.0%)	0.03
Concomitant disorders
Heart diseases	2 (2.6%)	6 (3.1%)	0.58
Diabetes	1 (1.3%)	0	0.29
Allergies	9 (11.5%)	14 (7.2%)	0.25
Gastrointestinal disorders	4 (5.1%)	4 (2.1%)	0.17
Hypercholesterolemia	1 (1.3%)	0	0.29
Endocrine disorders	11 (14.1%)	21 (10.9%)	0.46
Psychiatric disorders	12 (15.4%)	21 (10.9%)	0.30
Any concomitant disorder	34 (43.6%)	57 (29.5%)	0.03
Chronic use of medications other than AED	31 (39.7%)	47 (24.5%)	0.01
Number of currently used AEDs
Monotherapy	46 (59.0%)	118 (61.1%)	0.74
Two drugs	20 (25.6%)	57 (29.5%)	0.52
Three drugs	9 (11.5%)	17 (8.8%)	0.49
Four drugs	3 (3.8%)	1 (0.5%)	0.07
Currently used AEDs
Valproic acid	36 (46.1%)	72 (37.3%)	0.18
Lamotrigine	25 (32.0%)	48 (24.9%)	0.23
Levetiracetam	24 (30.8%)	71 (36.8%)	0.35
Ethosuximide	0	4 (2.1%)	0.51
Topiramate	9 (11.5%)	22 (11.4%)	0.97
Clonazepam	9 (11.5%)	4 (2.1%)	0.002
Phenobarbital	0	2 (1.0%)	0.51
Carbamazepine	12 (15.4%)	36 (18.6%)	0.52
Oxcarbazepine	8 (10.2%)	18 (9.3%)	0.81
Tiagabine	1 (1.3%)	1 (0.5%)	0.49
Phenytoin	0	1 (0.5%)	0.71
Gabapentin	0	3 (1.5%)	0.36
Vigabatrin	2 (2.6%)	0	0.08
Lacosamide	2 (2.6%)	4 (2.1%)	0.55
Primidone	0	1 (0.5%)	0.71
Clobazam	3 (3.8%)	3 (1.5%)	0.23

Abbreviation: AED, antiepileptic drug.

Table 4 Comparison of women with and without children among studied patients with epilepsy

Variable	Patients who have children (n=85)	Patients who do not have children (n=186)	P-value
Age (years); mean (SD)	35.6 (6.3)	26.8 (6.0)	<0.001
Age at onset of epilepsy (years); mean (SD)	17.6 (9.9)	13.0 (7.4)	<0.001
Age at menarche (years); mean (SD)	13.3 (1.6)	13.1 (1.7)	0.38
Onset of epilepsy before the menarche	25 (29.8%)	79 (42.5%)	0.04
Menstrual abnormalities	14 (16.5%)	64 (34.4%)	0.002
Epilepsy type
Generalized	18 (21.2%)	56 (30.1%)	0.13
Focal	63 (74.1%)	119 (64.0%)	0.10
Combined (generalized and focal)	0	6 (3.2%)	0.10
Unknown	4 (4.7%)	5 (2.7%)	0.30
Frequency of seizures
>1 per month	33 (38.8%)	68 (36.6%)	0.72
1–12 per year	21 (24.7%)	41 (22.0%)	0.63
<1 per year	31 (36.5%)	77 (41.4%)	0.15
Monotherapy	45 (52.9%)	119 (64.0%)	0.08

Table 5 Independent factors associated with menstrual abnormalities in studied women with epilepsy

Variablesa	Standard error	Wald statistics	P-value	OR (95% CI)
Chronic use of medication(s) other than AEDb	0.30	8.75	0.003	2.48 (1.35–4.53)
Age at onset of epilepsyc	0.02	7.18	0.008	0.95 (0.91–0.99)
Current use of clonazepam	0.65	6.58	0.010	5.36 (1.48–19.45)

Notes: χ² test=29.9; P<0.001.

a The following variables were subsequently removed from the model with the backward elimination procedure: current use of vigabatrin (P=0.66), age at menarche (P=0.59), onset of epilepsy before menarche (P=0.90), number of AEDs in current use (P=0.33), type of epilepsy (P=0.30), frequency of seizures (P=0.18), and age (P=0.11).

b When “chronic use of medication(s) other than AED” was replaced by the “presence of any chronic disorder”, the latter one was also an independent predictor of menstrual abnormalities (P=0.005; OR: 2.30, 95% CI: 1.28–4.14).

c OR per 1-year increase.

Abbreviation: AED, antiepileptic drug.

Table 6 Independent factors associated with having children in studied women with epilepsy

Variablesa	Standard error	Wald statistics	P-value	OR (95% CI)
Ageb	0.03	58.9	<0.001	1.24 (1.18–1.32)
Menstrual abnormalities	0.39	3.93	0.047	0.46 (0.21–0.99)
Number of currently used AEDs	0.25	3.93	0.047	0.61 (0.38–0.99)

Notes: χ² test=101.9; P<0.001.

a The following variables were subsequently removed from the model with the backward elimination procedure: onset of epilepsy before menarche (P=0.73), type of epilepsy (P=0.51), frequency of seizures (P=0.51), and age at onset of epilepsy (P=0.29).

b OR per 1-year increase.

Abbreviation: AED, antiepileptic drug.