(b) Prenatal intervention studies using the 2009 IOM gestational weight gain recommendations

Reference, Sample characteristics	Treatment		Gestational weight gain (GWG) (kg)			Maternal weight retention postpartum (PP) (kg)			Infant birth weight (g)
	Control	Intervention	Control	Intervention	P value	Control	Intervention	P value	Control	Intervention	P value
Claesson et al. [56]    Design non RCT      N = 368 C = 208 I = 160   Country   Sweden   Ethnicity   Swedish   Age   C = 30.2 ± 4.9   I = 29.7 ± 4.5   Parity   C = 48% nulliparous   I = 42% nulliparous   SES   C = 26% unskilled workers   I = 20% unskilled workers   Prepreg BMI   BMI ≥ 30   Gestational age at recruitment   10–12 weeks   Duration of study   NA	Standard prenatal care	Motivational interview/talk in early pregnancy      Nutrition   Information about nutrition during pregnancy      Physical activity   Possibility to attend aqua aerobic classes (1-2/week)    Other   30 min-visit/week for motivational talks, weight control, Additional written information about eating and food intake if needed      Delivered by trained midwives	At delivery   11.3 ± 5.8      <7.0 kg   (study goal) 21%	At delivery   8.7 ± 5.5      <7.0 kg (study goal) 36%	<0.001            0.003	At 10–12 w PP   0.75 ± 5.34	At 10–12 w PP   −2.15 ± 5.88	<0.001	3,679 ± 571	3,688 ± 681	0.89
Shirazian et al. [57]    Design Historical cohort      N = 28 C = 20 I = 21   Country   United States   Ethnicity   C = 80% Latina I = 67% Latina   Age   C = 24.4 ± 5.6 I = 29.0 ± 5.1   Parity   C = 50% nulliparous I = 19% nulliparous   SES   NA   Prepreg BMI   C = 34.2 ± 5.3 I = 36.2 ± 5.2   Gestational age at recruitment   ≤12 weeks   Duration of study   until delivery	Standard prenatal care	6 seminars and at least 5 one-on-one counseling sessions or phone calls      Nutrition   Written material, seminars and counseling sessions to promote healthy eating, facilitate calories counting, kept food diary      Physical activity   Written material, seminars and counseling sessions to encourage walking, received pedometer to monitor      Other   Written material, seminars and counseling sessions to educate the women on obesity and pregnancy and healthy living; goal: GWG < 7 kg      Delivered by study coordinators	Last body weight   15.4 ± 7.5*      ≤6.8 kg   (study goal) 15% did not exceed         *Time of last body weight measurement unclear	Last body weight   8.1 ± 7.4*       ≤6.8 kg   (study goal) 38% did not exceed         *Time of last body weight measurement unclear	0.003               0.16	NA	NA	—	3,610 ± 548	3,458 ± 603	0.40
Lindholm et al. [66]    Design single-arm study      N = 25   Country   Sweden   Ethnicity   Swedish   Age   31.7 ± 3.2   Parity   median = 1 (0–3) SES   na Prepreg BMI   35.4 ± 4.4   Gestational age at recruitment   8–12 weeks   Duration of study   NA		Meeting a midwife every 15 days and 2 group support sessions.      Nutrition   Initial individual consultation, instructed to eat after “the plate model” and to keep an all-inclusive food intake diary.       Physical activity   Supervised exercise program      Frequency   1/week   Intensity   NA Duration   40 min   Type   Water aerobics      Asked to exercise 30 min/day PA on other days      Delivered by midwives and dietician	NA	Last body weight   6.9 ± 6.4*      ≤6.0 kg    (goal of study) 56%      *Time of last body weight measurement unclear	—               —	NA	NA	—	NA	3,484 ± 453	—
Hui et al. [60]      Design RCT      N = 190 C = 88 I = 102   Country   Canada   Ethnicity   C = 25% aboriginal I = 17% aboriginal   Age   C = 28.7 ± 5.9   I = 30.1 ± 5.2   Parity   C = na   I = na   SES   C = 48,602 ± 29,628 (high) I = 50,833 ± 23,792 (high) Prepreg BMI   C = 25.7 ± 5.1 I = 24.9 ± 5.4   Gestational age at recruitment   <26 weeks   Duration of study   until 36 weeks of gestation	Standard prenatal care	Nutrition   Personalized dietary counseling      Physical activity   Supervised exercise session      Frequency   1/week Intensity   mild-to-moderate Duration  30–45 min   Type aerobic and strength exercise         Women were asked to perform several sessions of exercise sessions at home. VHS and DVD to assist with home-based exercises    Delivered by dietitians and licensed fitness trainers	At delivery   15.2 ± 5.9      Adherence to 2009 IOM   45% did not exceed	At delivery 14.1 ± 6.0      Adherence to 2009 IOM  65% did not exceed	0.28            0.008	NA	NA	—	3,516 ± 530      LGA n = 15 (17%)	3,490 ± 509      LGA n = 12 (12%)	0.73         0.41
Vinter et al. [62]    Design RCT      N = 304 C = 154 I = 150   Country   Denmark   Ethnicity: Danish   Age: C = 29.0 (27–32) I = 29.0 (26–31) Parity   C = 55% nulliparous I = 53% nulliparous   SES   C = 65% ≥12 yrs I = 74% ≥12 yrs Prepreg BMI: C = 33.3 (31.7–36.9) I = 33.4 (30.7–36.5) Gestational age at recruitment   10–14 weeks   Duration of study   until delivery	Access to a website with nutrition and PA advices	Nutrition   Personalized dietary counseling 4 times during the intervention      Physical activity   free membership to gym Supervised exercise session 1x week      Frequency   1/week Intensity   moderate Duration60 min   Type   aerobic, elastic band, balance exercise      Other   group sessions 4–6 times.       Women were encouraged to be active every day for 30–60 min Pedometers were provided      Delivered by dieticians and physiotherapists	At 35 weeks gestation   8.6 (5.7–11.5)    Adherence to 2009 IOM   53% did not exceed	At 35 weeks gestation   7.0 (4.7–10.6)    Adherence to 2009 IOM   65% did not exceed	0.01            0.058	NA	NA	—	3,593 (3,335–3,930)    >4,000 g n = 39 (25%)	3,742 (3,464–4,070)    >4,000 g n = 40 (32%)	0.039               0.07

Abbreviations: RCT: randomized controlled trial; N: total number; C: control group; I: intervention group; SES: socioeconomic status; prepreg BMI: body mass index prior to pregnancy; IOM: Institute of Medicine; NA: non available; NS: non significant, NW: normal weight; OW: overweight; OB: obese.