Background
Methods
Participants
Randomisation
Intervention
Ultrasound assessment
Fetal biometry measures
Fetal growth velocities
Fetal adiposity measures
Statistical analysis
Results
Participant characteristics
Characteristic | Metformin Group N = 255 | Placebo Group N = 256 | Total N = 511 |
---|---|---|---|
Maternal age (years; mean (SD)) | 29.88 (5.55) | 30.15 (5.38) | 30.02 (5.46) |
Gestational age at trial entry (weeks) Median (IQR) | 16.29 (14.43, 18.00) | 16.21 (14.57, 18.07) | 16.29 (14.43, 18.00) |
BMI (kg/m2) Median (IQR) | 32.40 (28.70, 37.57) | 32.05 (29.10, 36.80) | 32.30 (28.90, 37.20) |
BMI category (kg/m2) N (%): | |||
BMI 25.0–29.9 | 83 (32.55) | 83 (32.42) | 166 (32.49) |
BMI 30.0–34.9 | 74 (29.02) | 83 (32.42) | 157 (30.72) |
BMI 35.0–39.9 | 58 (22.75) | 48 (18.75) | 106 (20.74) |
BMI ≥ 40.0 | 40 (15.69) | 42 (16.41) | 82 (16.05) |
Nulliparity N (%) | 88 (34.51) | 91 (35.55) | 179 (35.03) |
Smoker N (%) | 24 (9.41) | 43 (16.80) | 67 (13.11) |
Height at trial entry (cm) Mean (SD) | 165.24 (6.76) | 164.89 (6.78) | 165.07 (6.76) |
Weight at trial entry (kg) Mean (SD) | 92.86 (19.79) | 91.87 (19.76) | 92.36 (19.76) |
Ethnicity N(%) | |||
Caucasian | 209 (81.96) | 219 (85.55) | 428 (83.76) |
Asian | 5 (1.96) | 7 (2.73) | 12 (2.35) |
Aboriginal/Torres Strait Islander | 6 (2.35) | 7 (2.73) | 13 (2.54) |
African | 6 (2.35) | 0 (0.00) | 6 (1.17) |
Other/unknown | 29 (11.38) | 23 (8.98) | 52 (10.18) |
SEIFA IRSD Quintile N(%) | |||
Quintile 1 | 75 (29.41) | 93 (36.33) | 168 (32.88) |
Quintile 2 | 78 (30.59) | 74 (28.91) | 152 (29.75) |
Quintile 3 | 31 (12.16) | 30 (11.72) | 61 (11.94) |
Quintile 4 | 52 (20.39) | 43 (16.80) | 95 (18.59) |
Quintile 5 | 19 (7.45) | 16 (6.25) | 35 (6.85) |
Fetal biometry measures
Outcome | Time point | Metformin group Mean (SD) | Control group Mean (SD) | Unadjusted treatment effect (95% CI) | Unadjusted P-value | Adjusted treatment effect (95% CI) | Adjusted P-value |
---|---|---|---|---|---|---|---|
Biparietal diameter (cm) | 0.138* | 0.102* | |||||
20 weeks | 4.66 (0.34) | 4.69 (0.35) | 0.328 | 0.232 | |||
28 weeks | 7.13 (0.50) | 7.15 (0.41) | −0.02 (− 0.10, 0.06) | 0.645 | − 0.02 (− 0.10, 0.07) | 0.671 | |
36 weeks | 8.94 (0.42) | 8.88 (0.39) | 0.06 (−0.01, 0.14) | 0.110 | 0.07 (− 0.01, 0.14) | 0.076 | |
Head circumference (cm) | 0.299* | 0.200* | |||||
20 weeks | 17.38 (1.20) | 17.45 (1.36) | −0.07 (−0.29, 0.16) | 0.551 | −0.09 (− 0.31, 0.13) | 0.431 | |
28 weeks | 26.46 (1.55) | 26.43 (1.26) | 0.04 (−0.22, 0.30) | 0.744 | 0.05 (−0.22, 0.31) | 0.727 | |
36 weeks | 32.36 (1.23) | 32.20 (1.21) | 0.17 (−0.05, 0.40) | 0.134 | 0.19 (−0.04, 0.42) | 0.100 | |
Femur length (cm) | 0.018* | 0.012* | |||||
20 weeks | 3.26 (0.30) | 3.28 (0.30) | −0.03 (−0.08, 0.02) | 0.267 | −0.04 (− 0.09, 0.01) | 0.127 | |
28 weeks | 5.29 (0.37) | 5.29 (0.30) | 0.01 (−0.06, 0.07) | 0.841 | 0.00 (−0.06, 0.07) | 0.909 | |
36 weeks | 6.92 (0.32) | 6.85 (0.33) | 0.08 (0.01, 0.14) | 0.015 | 0.07 (0.01, 0.14) | 0.019 | |
Abdominal circumference (cm) | 0.992* | 0.959 | |||||
20 weeks | 15.56 (1.37) | 15.65 (1.29) | −0.09 (−0.32, 0.14) | 0.457 | −0.10 (− 0.32, 0.12) | 0.368 | |
28 weeks | 24.62 (1.75) | 24.70 (1.56) | −0.07 (− 0.37, 0.24) | 0.669 | − 0.05 (− 0.36, 0.26) | 0.747 | |
36 weeks | 32.82 (1.87) | 32.92 (1.99) | −0.07 (− 0.43, 0.29) | 0.690 | − 0.07 (− 0.43, 0.29) | 0.707 | |
Estimated fetal weight (g) | 0.720* | 0.756* | |||||
28 weeks | 1272.36 (248.33) | 1268.81 (201.23) | 5.05 (−36.72, 46.82) | 0.813 | 5.40 (−36.93, 47.74) | 0.803 | |
36 weeks | 2932.32 (399.97) | 2914.27 (417.68) | 18.98 (−56.99, 94.95) | 0.624 | 17.61 (−57.67, 92.88) | 0.647 |
Fetal adiposity measures
Outcome | Time point | Metformin group Mean (SD) | Control group Mean (SD) | Unadjusted treatment effect (95% CI) | Unadjusted P-value | Adjusted treatment effect (95% CI) | Adjusted P-value |
---|---|---|---|---|---|---|---|
Mid-thigh fat mass (cm2) | 0.845* | 0.843* | |||||
28 weeks | 4.24 (1.03) | 4.21 (1.09) | 0.04 (−0.27, 0.35) | 0.805 | 0.02 (− 0.29, 0.33) | 0.902 | |
36 weeks | 9.87 (2.79) | 9.95 (2.47) | −0.05 (− 0.95, 0.84) | 0.908 | − 0.07 (− 0.94, 0.80) | 0.870 | |
Abdominal fat mass (mm) | 0.144* | 0.199* | |||||
28 weeks | 3.60 (1.17) | 3.60 (1.08) | 0.01 (−0.31, 0.34) | 0.935 | 0.06 (−0.27, 0.39) | 0.718 | |
36 weeks | 6.42 (1.41) | 5.98 (1.51) | 0.42 (−0.05, 0.88) | 0.077 | 0.42 (−0.05, 0.89) | 0.079 | |
Subscapular fat mass (mm) | 0.919* | 0.655* | |||||
28 weeks | 3.22 (0.80) | 3.20 (0.88) | 0.02 (−0.21, 0.25) | 0.863 | 0.03 (−0.19, 0.25) | 0.760 | |
36 weeks | 4.84 (1.44) | 4.85 (1.48) | −0.00 (− 0.42, 0.41) | 0.985 | − 0.07 (− 0.48, 0.34) | 0.740 |