Study | Age group/mean age | Socio-economic status | Education | Rural/urban | Parity | Trimester | Exposure to sunlight | Seasons of study |
---|---|---|---|---|---|---|---|---|
Ajmani et al. 2016 [35] | 20–25 | Lower, upper lower, lower middle, upper middle | Illiterate, primary level, graduate | Urban | Multi-gravida and Primigravida | All trimesters | NM | NM |
Farrant et al. 2009] [32] | 20–26 | Upper, lower | NM | Urban | NM | < 32 weeks of pregnancy | NM | Summer, Winter |
Jani et al. 2014 [9] | 26.7 ± 4.1 | NM | NM | Rural | NM | 2nd trimester | Summer: 35.4 ± 15.9 h/day * %BSA | Summer, Winter |
Marwaha et al. 2011 [7] | 19–30 | Lower middle | NM | Urban | 1, 2, and > 2 | All trimesters | 1st trimester: 10–60 min 2nd trimester: 10–60 min 3rd trimester; 10–20 min | Summer, Winter |
Sachan et al. 2005 [31] | 24 ± − 4.1 | Lower, middle | NM | Rural and urban | NM | 3rd trimester | Urban: 4.1 ± 3.2 h/day*%BSA Rural: 9.7 ± 8.1 h/day*%BSA | Autumn |
Sahu et al. 2009 [33] | 20–25 | Lower, upper | NM | Rural and urban | < 3 | 3rd trimester | Mean 14:00 ± 2 h | Spring summer |
Sharma et al. 2016 [36] | 22–23 | Lower, upper lower, lower middle upper middle | Both educated and not educated | Urban | Primigravida | Full term | NM | Summer, Winter |
Singla et al. 2015 [34] | 18–35 | Upper, upper middle, lower, lower middle | NM | Urban | Nulliparous, 1 and 2 | 2nd trimester | Summer: shorter ≤ 30 min Longer > 30 min Winter: Shorter ≤ 90 min Longer > 90 min | Summer, Winter |
Krishnaveni et al. 2011 [37] | 24 ± 4.3 | Lower | NM | NM | NM | 3rd trimester | NM | NM |
Veena et al. 2017 [38] | 23.9 ± 4.3 | Lower | < 10(34.9% − 10(31.7%) > 10(33.4% | NM | 1, 2, and > 2 | 3rd trimester | NM | NM |
30.83 ± 4.0 | upper | NM | urban | NM | 2nd trimester | NM | NM | |
Kumar et al. 2015 [40] | NM | NM | NM | NM | NM | NM | NM | NM |
Chary et al. 2015 [41] | 24.5 ± 2.6 | Upper, upper middle, lower, lower middle | Illiterate, primary level, High School Post high school | Rural and urban | NM | 3rd trimester | < 60 min | NM |
Dasgupta et al. 2012 [42] | 20–40 | NM | NM | NM | NM | 1st trimester | 33 ± 9.07% | Summer, rainy |
Sablok et al. 2015 [43] | NM | Lower, middle | NM | NM | Primigravida | 2nd trimester | < 1 h/day > 4 h/day | NM |