Table 2. Summary of baseline characteristics.
| ID | Country | Year of research | Study design | Mean age* | Mean pre-pregnancy BMI* | Gestation week at recruitment* | Parity -Nulliparous | Other health behaviour |
| years | Kg/m2 | weeks | (%) | |||||
| PC1 | USA | N/A | RCT | 26.5±5.02 | N/A | N/A | N/A | N/A |
| DP1 | USA | 2006–2008 | RCT | 28.6±5.2 | 26.3±5.6 | 13.6±1.8 | 76.3 | N/A |
| DP2 | USA | 2006–2007 | RCT | 26.5 | 27.3±7.0 | 19.1±6.0 | 53 | N/A |
| DP3 | Australia | 2007–2008 | RCT | 30.3±5.3 | 35.2±7.0 | N/A | N/A | 4% smokers |
| DP5 | Finland | 2002–2005 | RCT | 26.5 | 23·6±3·8 | N/A | 58 | 18.5% smokers |
| DP6 | Belgium | 2006–2008 | RCT | 28.3±4.0 | 34.1±4.5 | 9.7±2.6 | 42.3 | 6.2% smokers |
| DP7 | Sweden | 2003–2005 | CBA | 30.0±4.7 | N/A | 10–12 | 41.9 | 8.4% smokers |
| DP8 | USA | 1998–2005 | RCT | 26.8 | N/A | 12 to 28 | 16.3 | N/A |
| DP9 | Australia | 2007–2008 | RCT | N/A | N/A | 14 | N/A | N/A |
| DP10 | USA | 2005–2007 | RCT | 26.7±6.0 | 25.6±6.0 | 13.6±3.6 | 45.6 | 5.4% smokers |
| DP11 | Denmark | N/A | RCT | 28±4.0 | 34.9±4 | 15±2 | N/A | N/A |
| DP12 | Finland | 2004–2005 | CCT | 27.6±4.5 | 23.7±3.9 | 8–9 | 100 | 32% smokers |
| DP14 | USA | N/A | RCT | 25.5±4.8 | 26.9±4.4 | 14.5±3.5 | 47 | N/A |
| DP18 | Canada | 2004–2005 | RCT | 26.2±5.4 | 23.4±3.9 | <26 | N/A | N/A |
| DP19 | Norway | 2007–2008 | RCT | 31.2±3.7 | 23.8±3.8 | 17.3±4.1 | 100 | 4% smokers |
*Mean ± Standard Deviation; N/A = Not applicable or Not reported; CBA = Control before and after; RCT = Randomised controlled trial; CCT = Controlled clinical trial.