Table 3.
Summary of findings on gestational weight gain in twin pregnancies and infant outcomes among studies that controlled for prepregnancy BMI and gestational age at delivery
| Study | GWG measure | Outcome defined | Control variables | Results |
|---|---|---|---|---|
| Fetal growth | ||||
| Bohni et al. 2011 (20) | Total GWG | Twin BW<10th %ile; Mean twin BW<2500g; placental weight | Pregravid BMI, GA, parity, smoking, maternal age | Total GWG was 2.1 kg greater in mothers with both twins’ BW>10th percentile than in mothers with one or both twins’ BW<10th percentile (p=0.02) and was 2.2 kg greater among mothers of twins with mean BW≥2500g than mothers with mean BW <2500g (p=0.03). Total GWG was not associated with placental weight (beta=0.003, p=.19). |
| Brown & Schloesser 1990 (21) | Total GWG | Twin BW | None | Total GWG was lower for term deliveries of infants <2501 g and 2501–3000 g vs. term deliveries of infants 3001–3500 g in UW (35.1 lb and 39.3 lb vs. 44.2 lb, p<0.05) and NL (31.2 lb and 37.9 lb vs. 40.9 lb, p<0.05). In OB total GWG was lower for deliveries of infants <2501 g vs. 3001–3500 g (29.5 lb vs. 37.2 lb, p<0.05). There were no differences for OW or severely OB. |
| Chu & D’Angelo 2009 (22) | Total GWG | LBW (BW<2500g) of 1 randomly selected twin | GA and maternal age | LBW decreased as total GWG increased from ≤14 lb to ≥65 lb for NL (61.2% to 35.6 lb, p<0.05); OV (61.4% to 44.0%, p<0.05); OB (52.7% vs. 48.0%, p<0.05) as well as from 15–24 lb to 55-64 lb for UW (87.2% vs. 54.9%, p<0.05). |
| Eller et al. 1993 (24) | Rate of total GWG | Mean twin BW centile, mean twin BW ≥25th percentile | Race, smoking, GA, % ideal body weight | The rate of total GWG was positively associated with mean twin BW centile (p<0.05). Weekly rate of gain was higher in mothers delivering twins with mean BW centile ≥25th %ile (1.01 lb/wk) than those with mean BW centile <25th %ile (0.81 lb/wk, p-value not shown). |
| Fox et al. 2010 (26) | Adequacy of GWG 1 | Both twins BW >1000g, >1500 g, 2500 g; Any twin <5% of birth weight standard | None | Normal total GWG vs. low total GWG % of both twins >1000 g NL: 97.5% vs. 91.2%, p<0.05 OV: 100% vs. 94.1%, p=0.15 OB: 100% vs. 100% % of both twins >1500 g NL: 92.6% vs. 87.5%, p=0.23 OV: 97.1% vs. 88.2%, p=0.21 OB: 100% vs. 100% % of both twins >2500 g NL: 38.8% vs. 22.5%, p=0.02 OV: 41.2% vs. 29.4%, p=0.41 OB: 47.6% vs. 50%, p=0.91. % of any twin <5% BW standard NL: 21.5% vs. 35.0%, p=0.03 OV: 23.5% vs. 17.6%, p=0.63 OB: 28.6% vs. 25%, p=0.85 Results were similar when limited to births ≥37 weeks |
| Fox et al. 2011 (27) | Adequacy of GWG 1 | Twin BW at ≥37 wk; Both twins BW >2500 g at ≥37 wk | Race, pregravid BMI, age, IVF, GA, chorionicity, fetal reduction | Poor total GWG vs. normal total GWG vs. excessive total GWG Larger twin BW at ≥37 wks: Overall: 2,699.1g vs. 2,887.2g vs. 3,011.2g, p<0.001 NL: 2,679.5g vs. 2,805.1g vs. 2,991.6g, p<0.001 Smaller twin BW at ≥37 wks: Overall: 2,475.2g vs. 2,578.8g vs. 2,711.9g, p=0.002 NL: 2,441.3g vs. 2,504.5g vs. 2,669.5g, p=0.004 % of both twins >2500 g at ≥37 wks: Overall: 40.0% vs. 60.5% vs. 79.5%, p<0.001 NL: 32.6% vs. 56.1% vs. 76%, p=0.001 |
| Gónzalez-Quintero et al. 2012 (28) | Total GWG compared with the 2009 IOM recs (<IOM vs. ≥IOM) | Both twins BW >1500g and >2500g | None | Total GWG <IOM vs. ≥IOM % both twins BW >1500g Overall: 85.3% vs. 92.4%, p<0.001 NL: 86.4% vs. 92.8%, p<0.001 OV: 86.1% vs. 91.7%, p<0.01 OB: 81.3% vs. 92.1%, p<0.001 % both twins BW >2500g Overall: 24.4% vs. 37.3%, p<0.0001 NL: 22.0% vs. 33.9%, p<0.001 OV: 28.6% vs. 40.7%, p<0.001 OB: 26.6% vs. 42.3%, p<0.001 |
| Lantz et al. 1996 (30) | Rate of GWG <20 wk and ≥20 wk | Both twins ≥2500g | None | Both twins BW ≥2500g vs. both twins BW <2500g Rate of gain 0–20wk UW: 1.13 lb/wk vs. 0.70 lb/wk, p=0.02 NL: 0.61 lb/wk vs. 0.75 lb/wk, p=ns OV: 0.46 lb/wk vs. 0.38 lb/wk, p=ns Rate of gain 20wk to delivery UW: 1.92 lb/wk vs. 1.29 lb/wk, p=0.03 NL: 1.63 lb/wk vs.1.29 lb/wk, p=0.05 OV: 1.85 lb/wk vs. 1.74 lb/wk, p=ns Rate of total GWG UW: 1.42 lb/wk vs. 0.95 lb/wk, p<0.001 NL: 1.15 lb/wk vs. 0.88 lb/wk, p=0.04 OV: 1.07 lb/wk vs. 0.85 lb/wk, p=ns |
| Luke et al. 1993a (38) | Rate of GWG <24 wk and ≥24 wk | Twin BW; BW ratio (twin BW divided by singleton BW standard at 50th %ile; BW ≤10th% | Race, parity, smoking, pregravid BMI, GA, twin gender discordancy | Rate of total GWG that was low (≤0.85 lb/wk) at <24 weeks and low (<1 lb/wk) at ≥24 weeks was positively associated with sum of twins’ BW (beta=-0.20, p<0.001), BW of smaller twin (beta=-0.19, p<0.001), BW of larger twin (beta=-0.20, p<0.001), sum of twins BW ratio (beta=-0.24, p<0.001), smaller twin BW ratio (beta=-0.22, p<0.001), larger twin BW ratio (beta=-0.26, p<0.001), smaller twin BW ≤10th% (aOR 6.99 (95% CI: 2.1, 23.7) p<0.005), and larger twin BW ≤10th% (aOR 5.33 (95% CI: 1.9, 14.8), p<0.005). |
| Luke & Leurgans 1996 (36) | Total GWG | Mean twin BW; Mean twin z-score | Pregravid BMI, smoking | Total GWG associated with increased average twin BW (beta=4.6, p<0.001) and average twin BW z-score (beta=0.02, p<0.001). |
| Luke et al. 1998 (37) | Rate of GWG <20 wk, 20–28 wk, 28–36 wk | Rate of fetal growth, sum of twin BW | Race, parity, smoking, pregravid BMI, GA, maternal age |
Rate of the sum of fetal growth 20–28 wk GWG <20 wk (per lb gained): beta=0.55 g/wk, p<0.001 GWG 20–28 wk (per lb gained): beta=1.98 g/wk, p<0.001 Rate of the sum of fetal growth 28–36 wk GWG <20 wk (per lb gained): beta=0.84 g/wk, p<0.01 GWG 20–28 wk (per lb gained): beta=2.99 g/wk, p<0.001 Sum of twin pair BW GWG <20 wk (per lb gained): beta=14.15 g, p<0.001 GWG 20–28 wk (per lb gained): beta=20.45 g, p<0.001 GWG 28–36 wk (per lb gained): beta=8.72 g, p<0.05 if not preeclamptic; beta=1.38 if preeclamptic |
| Luke et al. 2004 (32) | Rate of GWG at <20 weeks | <10th %ile for fetal femur length, AC, HC; <10th %ile for any of the 3 measures | Race, short stature, parity, smoking, chorionicity, fetal gender, fetal reduction, insurance, ART, preeclampsia | GWG <0.65 lb/wk at <20 weeks was associated with an increased odds of fetal femur length <10th% at 28wks (aOR 3.39 95% CI: 1.34, 8.59, p<0.05) and having a fetus with a femur length, AC, or HC <10th% at 28 wks (aOR 2.62 95% CI: 1.14, 5.99, p<0.01). |
| Schwendemann et al. 2005 (42) | Rate of GWG after signs of preterm labor | At least 1 SGA infant | Prepregnancy BMI, smoking | The OR (95% CI) for delivering at least 1 SGA infant was 1.35 (1.16, 1.56) for GWG <0.5 lb/wk (referent group not identified) and 0.77 (0.68, 0.86) for GWG >1 lb/wk (referent group not identified). |
| Preterm birth | ||||
| Fox et al. 2010 (26) | Adequacy of total GWG1 | GA at delivery; PTB and sPTB <37, <35, <32, <28 weeks; indicated PTB (not defined) | None | Normal total GWG vs. low total GWG GA at delivery NL: 36.0 vs. 35.4 wk, p=0.14 OV: 36.2 vs. 34.4 wk, p=0.01 OB: 36.7 vs. 36.5 wk, p=0.78 % PTB <37 weeks; % sPTB <37 weeks NL: 57.9% vs. 62.5%, p=0.51; 46.9% vs. 55.2%, p=0.29; OV: 50.0% vs. 64.7%, p=0.32; 26.1% vs. 60.5%, p=0.03 OB: 47.6% vs. 50.0%, p=0.90; 33.3% vs. 42.9%, p=0.66 % PTB <35 weeks; % sPTB <35 weeks NL: 19.8% vs. 25%, p=0.39; 16.5% vs. 21.1%, p=0.43 OV: 20.6% vs. 52.9%, p=0.02; 13.3% vs. 46.7%, p=0.01 OB: 9.5% vs. 25%, p=0.28; 9.5% vs. 25%, p=0.28 % PTB <32 weeks; % sPTB <32 weeks NL: 5.0% vs. 13.8%, p=0.02; 3.4% vs. 11.5%, p=0.02 OV: 0% vs. 17.6%, p=0.01; 0% vs. 17.0%, p=0.01 OB: 4.8% vs. 0%, p=0.53; 4.8% vs. 0%, p=0.53 % PTB <28 weeks; % sPTB <28 weeks NL: 1.7% vs. 6.2%, p=0.08; 1.7% vs. 6.2%, p=0.08 OV: 0% vs. 5.9%, p=0.15; 0% vs. 5.9%, p=0.15 OB: 0% vs. 0%, p=na; 0% vs. 0%, p=na % Indicated PTB NL: 19.9% vs. 15.0%, p=0.49 OV: 32.4% vs. 11.4%, p=0.11 OB: 14.3% vs. 12.5%, p=0.9 |
| Gónzalez-Quintero et al. 2012 (28) | Rate of total GWG compared with the 2009 IOM recs (<IOM vs. ≥IOM) 1 | GA; sPTB <37, <35, <32, <28 wk | None | Normal total GWG vs. low total GWG % sPTB <37 weeks; % sPTB <35 weeks; % sPTB <32 weeks; % sPTB <28 weeks All: 33.3% vs. 41.4%; 16.4% vs. 24.0%; 4.4% vs. 9.0%; 1.1% vs. 3.5%, all p<0.001 NL: 34.5% vs. 44.2%; 16.7% vs. 24.9%; 4.3% vs. 8.6%; 1.0% vs. 3.1%; all p<0.0001 OV: 31.8% vs. 39.5%; 16.2% vs. 23.5%; 4.6% vs. 8.2%; 1.1% vs. 3.1%, all p<0.05 OB: 35.3% vs. 32.0% p=0.3; 16.2% vs. 21.9% p<0.05; 4.5% vs. 11.2%, p<0.001; 1.4% vs. 5.0%, p<0.01 |
| Luke et al. 1993a (38) | Rate of GWG <24 wk and ≥24 wk | PTB 28–32 wk, 33–34wk, 35–36 wk, 37–38 wk, 39–41 wk | None | The percent of mothers with low early (<24 weeks) rate of GWG (≤0.85 lb/wk) and low late (≥24 weeks) rate of GWG (<1 lb/wk) decreased as GA at delivery increased: 28–32 wk (29%) to 39–41 wk (10%, p<0.05). The % of mothers with low early rate of GWG (≤0.85 lb/wk) and high late rate of GWG (≥1 lb/wk) decreased as GA at delivery increased: 28–32 wk (3%) to 39–41 wk (24%, p<0.05). |
| “Optimal outcome” | ||||
| Luke et al. 1993a (38) | Rate of GWG <24 wk and ≥24 wk | A) BW of smaller twin >10th and ≤8 day hospital stay B) BW of smaller twin >10th, ≤8 day hospital stay, and GA 35–38 wk |
Race, parity, smoking, pregravid BMI, GA, twin gender discordancy | Having a low early (<24 weeks) rate of GWG (≤0.85 lb/wk) and a low late (≥24 weeks) rate of GWG (<1 lb/wk) was associated with an increased odds of an adverse neonatal outcome (defined as a pregnancy that did not meet the criteria for ideal outcome A or B) (aOR 4.26 95% CI:1.3, 14.3, p<0.05; aOR 3.35, 95% CI: 1.0, 10.9, p<0.05, respectively). Having a low early rate of GWG and high late rate of GWG (≥1 lb/wk) was associated with a reduced odds of an adverse neonatal outcome (defined as a pregnancy that did not meet the criteria for ideal outcome B): aOR 0.31, 95% CI: 0.13, 0.74, p<0.001. High early/high late rate of GWG and high early/low late rate of GWG were not associated with either outcome (adjusted results not shown). |
| Luke et al. 2003 (33) | Rate of GWG 0–20 wk, 21–28 wk, >28 wk | Optimal BW (2850–2928g at 36–38 wk), optimal fetal growth (105–110g/wk from 20–28 wk; 155–161g/wk from 28wk to term) | Smoking, parity, pregestational diabetes, GDM, PE, chorionicity, fetal growth <20 weeks | Authors’ conclusions on optimal rates of GWG at 0–20 wk, 21–28 wk, and 29 wk-delivery, respectively: UW: 0.57–0.79 kg/wk; 0.68–0.79 kg/wk; 0.57 kg/wk NL: 0.45–0.68 kg/wk; 0.57–0.79 kg/wk; 0.45 kg/wk OV: 0.45–0.57 kg/wk; 0.45–0.68 kg/wk; 0.45 kg/wk OB: 0.34–0.45 kg/wk; 0.34–0.57 kg/wk; 0.34 kg/wk |
AC, abdominal circumference; aOR, adjusted odds ratio; ART, assisted reproductive technologies; BMI, body mass index; BW, infant birth weight; CI, confidence interval; GA, gestational age; GDM, gestational diabetes; GWG, gestational weight gain; HC, head circumference; IOM, Institute of Medicine; IVF, in vitro fertilization; NL, normal weight before pregnancy; OB, obese before pregnancy; OV, overweight before pregnancy; PE, preeclampsia; PTB, preterm birth; sPTB, spontaneous preterm birth; UW, underweight before pregnancy
1
Rate of total GWG compared with the 2009 IOM recommendations divided by 37 weeks.