Skip to main content

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