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Table 1 Characteristics of three groups of monochorionic twin pregnancies

From: Placental erythropoietin expression is upregulated in growth-restricted fetuses with abnormal umbilical artery Doppler findings: a case–control study of monochorionic twins

 

Group 1 (n = 9)

Group 2 (n = 9)

Group 3 (n = 8)

p value

Maternal age at delivery

31.4 ± 6.2

31.1 ± 3.2

32.4 ± 2.2

0.80#

Gestational age of delivery (weeks)

36.7 ± 0.97

34.8 ± 1.7

30.7 ± 2.7

< 0.001#(Group1 > Group2 > Group 3)

Birth weight of the AGA (larger) twin (g)

2597 ± 271

2237 ± 395

1398 ± 403

< 0.001#(Groups 1 > Group 2 > Group 3)

Birth weight of the sIUGR (smaller) twin (g)

2333 ± 276

1573 ± 300

717 ± 232

< 0.001#(Groups 1 > Group 2 > Group 3)

Birth weight discordance (%)

10.0 ± 6.6

29.5 ± 7.4

48.9 ± 7.4

< 0.001#(Groups 3 > Group 2 > Group 1)

Cord plasma EPO-ratio

1.03 ± 0.20

1.36 ± 0.76

1.95 ± 0.59

0.01#(Group3 > Groups 1 and 2)

Cord plasma EPO of larger (AGA) fetus

(mIU/ mL)

14.2 ± 11.4

10.5 ± 9.2

24.7 ± 36.8

0.410#

Cord plasma EPO of smaller (sIUGR) fetus (mIU/ mL)

16.0 ± 14.6

12.7 ± 9.3

49.4 ± 71.8

0.153#

Maternal BMI at delivery

26.6 ± 1.9

27.4 ± 3.4

27.1 ± 3.2

0.880#

CPR of larger (AGA) fetus

1.39 ± 0.21

1.47 ± 0.29

1.74 ± 0.29

0.064#

CPR of smaller (sIUGR) fetus

1.41 ± 0.20

1.33 ± 0.13

0.45 ± 0.03

< 0.001#(Group3 < Groups 1 and 2)

Neonatal hemoglobin levels (larger/AGA) (g/dL)

14.8 ± 1.2

16.4 ± 1.8

16.8 ± 1.1

Neonatal hemoglobin levels (smaller/sIUGR) (g/dL)

14.4 ± 1.2

16.5 ± 2.3

15.6 ± 1.7

  1. Group 1: normal MC twins; group 2: twins with sIUGR without UA Doppler abnormalities; group 3: twins with sIUGR and UA Doppler abnormalities
  2. Birth-weight discordance: [(body weight of the larger or AGA twin - body weight of the smaller or sIUGR twin) / body weight of the larger or AGA twin] × 100%
  3. Cord plasma EPO-ratio: [plasma EPO level of the smaller (or the small-for-gestational-age) twin] / [plasma EPO concentration of the larger (or the appropriate-for-gestational-age) twin]
  4. CPR (cerebroplacental ratio) = (middle cerebral artery-pulsatility index) / (umbilical artery- pulsatility index)
  5. Abbreviations: MC monochorionic, sIUGR selective intrauterine growth restriction, AGA appropriate-for-gestational-age, EPO erythropoietin, CPR cerebroplacental ratio
  6. #One-way analysis of variance
  7. ※No significant difference was observed in the hemoglobin levels between the two fetuses in any of the groups of MC twins