Table 1 Summary characteristics of included studies
Characteristic | Number of studies (n = 96) | Percentage of total |
|---|---|---|
Year of publication | ||
1964–1980 | 7 | 7.29 |
1981–1990 | 19 | 19.79 |
1991–2000 | 22 | 22.92 |
2001–2005 | 8 | 8.33 |
2006–2010 | 12 | 12.50 |
2011–2015 | 28 | 29.17 |
Continent | ||
Europe | 56 | 58.33 |
North America | 18 | 18.75 |
Asia | 10 | 10.42 |
Trans-Continental | 5 | 5.21 |
Australia | 3 | 3.13 |
South America | 3 | 3.13 |
Africa | 1 | 1.04 |
Study design | ||
Observational cohort | 92 | 95.83 |
Case-control | 3 | 3.13 |
Randomized clinical trial | 1 | 1.04 |
Registry study | ||
Yes | 30 | 31.25 |
No | 66 | 68.75 |
Sample size | ||
18–50 | 16 | 16.67 |
51–100 | 26 | 27.08 |
101–300 | 32 | 33.33 |
301–500 | 8 | 8.33 |
501–1000 | 2 | 2.08 |
1001–7759 | 12 | 12.50 |
Number of interventionsa | ||
2–4 | 41 | 42.71 |
5–7 | 30 | 31.25 |
8–10 | 15 | 15.63 |
11–17 | 10 | 10.42 |
Funding | ||
Public | 21 | 21.88 |
Private | 7 | 7.29 |
Mixed public and private | 16 | 16.67 |
Not reported | 52 | 54.17 |
Indication | ||
Epilepsy | 89 | 92.71 |
Mixed indications | 1 | 1.04 |
Mental illness | 1 | 1.04 |
Not reported | 5 | 5.21 |
Epileptic control group | ||
Yes | 47 | 48.96 |
No/not reported/not applicable | 49 | 51.04 |
Mean maternal age, years | ||
24–26 | 11 | 11.46 |
27–29 | 23 | 23.96 |
30–34 | 7 | 7.29 |
Not reported | 55 | 57.29 |
Anti-epileptic drug exposure timing | ||
At least 1st trimester | 64 | 66.67 |
No/not reported | 32 | 33.33 |
Folic acid use | ||
Reported | 13 | 13.54 |
Not reported | 83 | 86.46 |
Alcohol use | ||
Reported | 5 | 5.21 |
Not reported | 91 | 94.79 |
Tobacco use | ||
Reported | 10 | 10.42 |
Not reported | 86 | 89.58 |