J Clin Gynecol Obstet

Journal of Clinical Gynecology and Obstetrics, ISSN 1927-1271 print, 1927-128X online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Gynecol Obstet and Elmer Press Inc

Journal website http://www.jcgo.org

Original Article

Volume 1, Number 2-3, June 2012, pages 31-35

Growth Discordance is not an Independent Risk Factor for Adverse Perinatal Outcomes in Twin Pregnancies

**Table 1.** Perinatal Characteristics and Outcomes of Concordant Monochorionic Twin Pregnancies and Discordant Dichorionic Twins by Actual Birth (or Fetal) Weight
	Concordant twin	Discordant twin
AGA, appropriate for gestational age; SGA: small for gestational age; IVF, in vitro fertilization; TTTS, twin-twin transfusion syndrome. *P < 0.05 vs. Concordant AGA-AGA twin pregnancies.
N	97	66	6	54
Maternal age (y)	30.3 ± 4.2	31.0 ± 4.0	30.2 ± 3.1	31.3 ± 4.0
Nulliparity	67 (69%)	34 (52%)	4 (67%)	32 (59%)
Smoking	7 (7.2%)	3 (4.5%)	0 (0%)	2 (3.7%)
History of infertility	5 (5.2%)	1 (1.5%)	0 (0%)	3 (5.6%)
IVF use	4 (4.1%)	1 (1.5%)	0 (0%)	1 (1.9%)
Maternal height (cm)	158 ± 6	159 ± 6	158 ± 3	159 ± 5
Maternal weight
At pre-pregnancy	51 ± 6	51 ± 6	52 ± 4	51 ± 6
At delivery	66 ± 8	64 ± 6	61 ± 5	64 ± 6
Hypertensive disorders	25 (26%)	20 (30%)	0 (0%)	11 (20%)
Geatstional diabetes	2 (2.1%)	1 (1.5%)	0 (0%)	1 (1.9%)
TTTS	4 (4.1%)	3 (4.5%)	1 (17%)	5 (9.3%)
Gestational age at delivery
Average (weeks)	35.5 ± 3.4	36.0 ± 2.4	34.5 ± 3.4	35.5 ± 3.4
< 28 weeks	4 (4.1%)	1 (1.5%)	0 (0%)	1 (1.9%)
< 33 weeks	9 (9.3%)	4 (6.1%)	1 (17%)	10 (19%)
Delivery mode
Elective Cesarean	39 (40%)	20 (30%)	2 (33%)	16 (24%)
Emergency Cesarean	32 (33%)	29 (44%)	2 (33%)	20 (30%)
Neonatal birth weight
Larger twin (g)	2402 ± 491	2233 ± 443	2454 ± 515	2163 ± 630
Smaller twin (g)	2336 ± 532	2067 ± 413*	2016 ± 484*	1515 ± 568*
Abnormal cord insertion
Larger twin	18 (19%)	15 (23%)	1 (17%)	13 (20%)
Smaller twin	26 (27%)	31 (47%)	2 (33%)	29 (54%)*
Fetal demise at ≥ 22 weeks
Larger twin	1 (1.0%)	1 (1.5%)	0 (0%)	1 (1.9%)
Smaller twin	2 (2.1%)	3 (4.5%)	0 (0%)	2 (3.7%)
Apgar score < 7 at 1min
Larger twin	3 (3.1%)	4 (6.1%)	1 (17%)	3 (5.6%)
Smaller twin	2 (2.1%)	5 (7.6%)	1 (17%)	10 (19%)*
Apgar score < 7 at 5 min
Larger twin	2 (2.1%)	2 (3.0%)	0 (0%)	1 (1.9%)
Smaller twin	1 (1.0%)	2 (3.0%)	0 (0%)	1 (1.9%)
Umbilical artery pH < 7.1
Larger twin	1 (1.0%)	2 (3.0%)	0 (0%)	0 (0%)
Smaller twin	2 (2.1%)	4 (6.1%)	1 (17%)	2 (3.7%)

Table 1. Perinatal Characteristics and Outcomes of Concordant Monochorionic Twin Pregnancies and Discordant Dichorionic Twins by Actual Birth (or Fetal) Weight

Concordant twin

Discordant twin

AGA-AGA

AGA-SGA

AGA-AGA

AGA-SGA

AGA, appropriate for gestational age; SGA: small for gestational age; IVF, in vitro fertilization; TTTS, twin-twin transfusion syndrome. *P < 0.05 vs. Concordant AGA-AGA twin pregnancies.

Maternal age (y)

30.3 ± 4.2

31.0 ± 4.0

30.2 ± 3.1

31.3 ± 4.0

Nulliparity

67 (69%)

34 (52%)

4 (67%)

32 (59%)

Smoking

7 (7.2%)

3 (4.5%)

0 (0%)

2 (3.7%)

History of infertility

5 (5.2%)

1 (1.5%)

0 (0%)

3 (5.6%)

IVF use

4 (4.1%)

1 (1.5%)

0 (0%)

1 (1.9%)

Maternal height (cm)

158 ± 6

159 ± 6

158 ± 3

159 ± 5

Maternal weight

At pre-pregnancy

51 ± 6

52 ± 4

51 ± 6

At delivery

66 ± 8

64 ± 6

61 ± 5

64 ± 6

Hypertensive disorders

25 (26%)

20 (30%)

0 (0%)

11 (20%)

Geatstional diabetes

2 (2.1%)

1 (1.5%)

0 (0%)

1 (1.9%)

TTTS

4 (4.1%)

3 (4.5%)

1 (17%)

5 (9.3%)

Gestational age at delivery

Average (weeks)

35.5 ± 3.4

36.0 ± 2.4

34.5 ± 3.4

35.5 ± 3.4

< 28 weeks

4 (4.1%)

1 (1.5%)

0 (0%)

1 (1.9%)

< 33 weeks

9 (9.3%)

4 (6.1%)

1 (17%)

10 (19%)

Delivery mode

Elective Cesarean

39 (40%)

20 (30%)

2 (33%)

16 (24%)

Emergency Cesarean

32 (33%)

29 (44%)

2 (33%)

20 (30%)

Neonatal birth weight

Larger twin (g)

2402 ± 491

2233 ± 443

2454 ± 515

2163 ± 630

Smaller twin (g)

2336 ± 532

2067 ± 413*

2016 ± 484*

1515 ± 568*

Abnormal cord insertion

Larger twin

18 (19%)

15 (23%)

1 (17%)

13 (20%)

Smaller twin

26 (27%)

31 (47%)

2 (33%)

29 (54%)*

Fetal demise at ≥ 22 weeks

Larger twin

1 (1.0%)

1 (1.5%)

0 (0%)

1 (1.9%)

Smaller twin

2 (2.1%)

3 (4.5%)

0 (0%)

2 (3.7%)

Apgar score < 7 at 1min

Larger twin

3 (3.1%)

4 (6.1%)

1 (17%)

3 (5.6%)

Smaller twin

2 (2.1%)

5 (7.6%)

1 (17%)

10 (19%)*

Apgar score < 7 at 5 min

Larger twin

2 (2.1%)

2 (3.0%)

0 (0%)

1 (1.9%)

Smaller twin

1 (1.0%)

2 (3.0%)

0 (0%)

1 (1.9%)

Umbilical artery pH < 7.1

Larger twin

1 (1.0%)

2 (3.0%)

0 (0%)

Smaller twin

2 (2.1%)

4 (6.1%)

1 (17%)

2 (3.7%)

**Table 2.** Perinatal Characteristics and Outcomes of Concordant Dichorionic Twin Pregnancies and Discordant Dichorionic Twins by Actual Birth (or Fetal) Weight
	Concordant twin	Discordant twin
AGA, appropriate for gestational age; SGA: small for gestational age; IVF, in vitro fertilization. *P < 0.05 vs. Concordant AGA-AGA twin pregnancies.
N	359	137	16	97
Maternal age (y)	32 ± 4	32 ± 4	31 ± 4	32 ± 4
Nulliparity	247 (69%)	77 (56%)	12 (75%)	70 (72%)
Smoking	9 (2.5%)	6 (4.4%)	0 (0%)	9 (9.3%)*
History of infertility	176 (49%)	51 (37%)	11 (66%)	47 (48%)
IVF use	136 (38%)	27 (20%)	5 (31%)	35 (36%)
Maternal height (cm)	159 ± 5	158 ± 5	160 ± 5	158 ± 6
Maternal weight
At pre-pregnancy	54 ± 9	53 ± 9	53 ± 5	53 ± 9
At delivery	67 ± 9	65 ± 10	67 ± 8	66 ± 8
Hypertensive disorders	32 (8.9%)	7 (5.1%)	5 (31%)	25 (26%)*
Geatstional diabetes	7 (1.9%)	2 (1.5%)	0 (0%)	2 (2.1%)
Gestational age at delivery
Average (weeks)	36.1 ± 2.0	36.1 ± 3.0	36.0 ± 1.5	36.1 ± 2.2
< 28 weeks	7 (1.9%)	2 (1.5%)	0 (0%)	1 (1.0%)
< 33 weeks	21 (5.8%)	10 (7.3%)	1 (6.3%)	4 (4.1%)
Delivery mode
Elective Cesarean	136 (38%)	39 (28%)	5 (31%)	36 (37%)
Emergency Cesarean	118 (33%)	40 (29%)	5 (31%)	19 (20%)
Neonatal birth weight
Larger twin (g)	2492 ± 462	2356 ± 519	2748 ± 265	2543 ± 459
Smaller twin (g)	2326 ± 451	2209 ± 475	2080 ± 234	1807 ± 410*
Abnormal cord insertion
Larger twin	56 (16%)	25 (18%)	3 (18%)	12 (12%)
Smaller twin	55 (15%)	31 (23%)	4 (25%)	25 (26%)*
Fetal demise at ≥ 22 weeks
Larger twin	2 (0.6%)	2 (1.5%)	1 (6.3%)	0 (0%)
Smaller twin	2 (0.6%)	2 (1.5%)	0 (0%)	2 (2.1%)
Apgar score < 7 at 1min
Larger twin	15 (4.2%)	3 (2.2%)	0 (0%)	5 (5.2%)
Smaller twin	18 (5.0%)	5 (3.6%)	1 (6.3%)	5 (5.2%)
Apgar score < 7 at 5 min
Larger twin	3 (0.8%)	0 (0%)	0 (0%)	0 (0%)
Smaller twin	4 (1.1%)	2 (1.5%)	0 (0%)	0 (0%)
Umbilical artery pH < 7.1
Larger twin	4 (1.1%)	0 (0%)	0 (0%)	1 (1.0%)
Smaller twin	5 (1.4%)	3 (2.2%)	0 (0%)	5 (5.2%)*

Table 2. Perinatal Characteristics and Outcomes of Concordant Dichorionic Twin Pregnancies and Discordant Dichorionic Twins by Actual Birth (or Fetal) Weight

Concordant twin

Discordant twin

AGA-AGA

AGA-SGA

AGA-AGA

AGA-SGA

AGA, appropriate for gestational age; SGA: small for gestational age; IVF, in vitro fertilization. *P < 0.05 vs. Concordant AGA-AGA twin pregnancies.

359

137

Maternal age (y)

32 ± 4

31 ± 4

32 ± 4

Nulliparity

247 (69%)

77 (56%)

12 (75%)

70 (72%)

Smoking

9 (2.5%)

6 (4.4%)

0 (0%)

9 (9.3%)*

History of infertility

176 (49%)

51 (37%)

11 (66%)

47 (48%)

IVF use

136 (38%)

27 (20%)

5 (31%)

35 (36%)

Maternal height (cm)

159 ± 5

158 ± 5

160 ± 5

158 ± 6

Maternal weight

At pre-pregnancy

54 ± 9

53 ± 9

53 ± 5

53 ± 9

At delivery

67 ± 9

65 ± 10

67 ± 8

66 ± 8

Hypertensive disorders

32 (8.9%)

7 (5.1%)

5 (31%)

25 (26%)*

Geatstional diabetes

7 (1.9%)

2 (1.5%)

0 (0%)

2 (2.1%)

Gestational age at delivery

Average (weeks)

36.1 ± 2.0

36.1 ± 3.0

36.0 ± 1.5

36.1 ± 2.2

< 28 weeks

7 (1.9%)

2 (1.5%)

0 (0%)

1 (1.0%)

< 33 weeks

21 (5.8%)

10 (7.3%)

1 (6.3%)

4 (4.1%)

Delivery mode

Elective Cesarean

136 (38%)

39 (28%)

5 (31%)

36 (37%)

Emergency Cesarean

118 (33%)

40 (29%)

5 (31%)

19 (20%)

Neonatal birth weight

Larger twin (g)

2492 ± 462

2356 ± 519

2748 ± 265

2543 ± 459

Smaller twin (g)

2326 ± 451

2209 ± 475

2080 ± 234

1807 ± 410*

Abnormal cord insertion

Larger twin

56 (16%)

25 (18%)

3 (18%)

12 (12%)

Smaller twin

55 (15%)

31 (23%)

4 (25%)

25 (26%)*

Fetal demise at ≥ 22 weeks

Larger twin

2 (0.6%)

2 (1.5%)

1 (6.3%)

0 (0%)

Smaller twin

2 (0.6%)

2 (1.5%)

0 (0%)

2 (2.1%)

Apgar score < 7 at 1min

Larger twin

15 (4.2%)

3 (2.2%)

0 (0%)

5 (5.2%)

Smaller twin

18 (5.0%)

5 (3.6%)

1 (6.3%)

5 (5.2%)

Apgar score < 7 at 5 min

Larger twin

3 (0.8%)

0 (0%)

Smaller twin

4 (1.1%)

2 (1.5%)

0 (0%)

Umbilical artery pH < 7.1

Larger twin

4 (1.1%)

0 (0%)

1 (1.0%)

Smaller twin

5 (1.4%)

3 (2.2%)

0 (0%)

5 (5.2%)*