Table 2 Characteristics of 7 case-control studies included in the meta-analysis.
Source | Study period | Age* (years) | No. of cases/participants | Method of exposure assessment | Exposure Period | Categories of exposure | Result | Adjusted Variables | Score of quality assessment |
|---|---|---|---|---|---|---|---|---|---|
Berkowitz et al.21, USA | 1977–78 | NA | 175/488 | Face to face interview | During the whole pregnancy | Leisure-time PA: No; Yes. | OR (95% CI): 1.00 (reference); 0.53 (0.36–0.78). | Race, family income, pre-pregnancy weight, maternal weight gain, infertility history, previous poor pregnancy outcome, vaginal bleeding, and alcohol consumption. | 7 |
Domestic PA (hour/week): <10; 10–19; 20–29; ≥30. | Crude RR (95% CI)†: 1.00 (reference); 0.83 (0.51–1.35); 0.67 (0.40–1.13); 0.85 (0.47–1.55). | NA | |||||||
Ritsmitchai et al.37, Thailand | 1993 | NA | 223/446 | Face to face interview | During the whole pregnancy | Leisure-time PA: No; Yes. | OR (95% CI): 1.00 (reference); 0.34 (0.16–0.73). | Pregnancy complications, previous poor pregnancy outcome, physical exertion at work, and prolonged standing at work. | 6 |
Saurel-Cubizolles et al.38, European countries | 1994–97 | NA | 2,230/6,137 | Face to face interview after delivery | During the whole pregnancy | Commuting PA (minute/day): <60; 60–120; >120. | OR (95% CI): 1.00 (reference); 0.94 (0.8–1.1); 0.97 (0.8–1.2). | Age, education, marital status, obstetric history, and country. | 6 |
Agbla et al.18, 2006, Benin | 2000–02 | NA | 99/203 | Face to face interview | During the whole pregnancy | Domestic PA: No; Yes. | Unadjusted OR (95% CI): 1.00 (reference); 0.72 (0.22–2.36). | NA | 9 |
Nelson et al.39, Thailand | 2006–07 | 26.9 ± 7.0 | 224/675 | Face to face interview | During the whole pregnancy | Leisure-time PA: No; Yes. | OR (95% CI): 1.00 (reference); 0.94 (0.61–1.46). | Age, BMI, and parity. | 7 |
Takito et al.40, Brazil | 2005 | 27.9 ± 5.2 | 117/351 | Face to face interview | A typical week of the second trimester | Domestic PA (hour/day): <2; 2–3.9; 4–5.9; ≥6. | OR (95% CI): 1.00 (reference); 0.50 (0.23–1.09); 0.56 (0.25–1.27); 0.38 (0.17–0.89). | Age, paid work, education, marital status, high blood pressure, vaginal bleeding, early rupture of membranes, hospitalization and antenatal consultations. | 7 |
Guendelman et al.41, 2013, USA | 2002–03 | 29.2 ± 5.3 | 344/1,042 | Telephone interview | Second trimester | Leisure-time PA (hour/week of vigorous activity): None; 1–2; ≥3. | Inverse OR (95% CI)‡: 1.00 (reference); 0.72 (0.50–1.06); 0.60 (0.43–0.83). | Race and month of delivery. | 7 |
