Perinatal outcome of monochorionic diamniotic twins with selective intrauterine growth restriction

Abstract

Objective To evaluate the perinatal outcome of three types of monochorionic diamniotic (MCDA) twins with selective intrauterine growth restriction (sIUGR).Methods From January 2010 to June 2013 clinical data of 37 pairs of MCDA twins (74 fetuses)with sIUGR and 40 pairs of normal MCDA twins (80 fetuses) in the same period were analyzed retrospectively.Fetuses with sIUGR were classified into three groups based on umbilical artery Doppler flow.There were 20 cases of type Ⅰ,11 cases of type Ⅱ and 6 cases of type Ⅲ.The perinatal outcome was compared between sIUGR and normal MCDA twins,and among the three types of sIUGR as well.Perinatal outcomes included gestational age at delivery,rate of intrauterine fetal death (IUFD),birth weight,twins discordance of birth weight,neonatal death and survival rate at 6 months.Results The gestational age of sIUGR group at delivery was significantly earlier than that of control group [(33.1 ± 3.0),(36.9 ± 3.2) weeks,respectively],and the rate of IUFD of both fetuses of sIUGR group was significantly higher [5.4％ (4/74),0,respectively],there was significant difference(P ＜ 0.05).In sIUGR group,the average birth weight of large or small twins [(2 030.8 ± 353.4),(1 529.0 ± 432.9) g] was smaller than those in control group [(2 471.5 ± 500.9),(2 346.0 ± 460.3) g],there was significant difference (P ＜ 0.05).The twins discordance of birth weight in sIUGR group was significantly larger [(27.2 ± 2.6)％] than that in control group [(8.0 ± 1.6)％] (P ＜0.05).The gestational age at delivery in type Ⅱ and type Ⅲ [(33.1 ± 5.0),(34.3 ± 2.8) weeks] was significantly earlier than that in control group (P ＜ 0.05).The rate of IUFD of both fetuses in type Ⅱ (18.2％,4/22) was significantly higher than that in type Ⅰ (0) and control group (0) (P ＜ 0.05).In sIUGR group,the average birth weight of small twins in type Ⅰ,type Ⅱ and type Ⅲ was (1 646.0 ± 433.5),(1 332.8 ± 310.5),(1 504.5 ± 382.2) g respectively,all of which was significantly smaller than that in control group (P ＜ 0.05).The average birth weight of small twins in type Ⅱ was smaller than type Ⅰ and the difference was statistically significant (P ＜ 0.05).In sIUGR group,the twins discordance of birth weight in type Ⅰ,type Ⅱ and type Ⅲ was (26.3 ±5.1)％,(31.0 ±1.6)％,(31.4 ±3.3)％ respectively,all of which was significantly larger than that in control group (P ＜0.05).There were no significant difference of the twins discordance of birth weight among the three types of sIUGR (P ＞ 0.05).Survival rate at 6 months in type Ⅱ (63.6％,14/22) was significantly lower than type Ⅰ (95.0％,38/40) and control group (92.5 ％,74/80) (P ＜ 0.05).Conclusions The perinatal outcome of MCDA twins with sIUGR is poor.The outcome is different among the three types of sIUGR,and type Ⅱ is the worst.Type Ⅱ is associated with a high risk of intrauterine fetal demise.It is important to monitor the intrauterine situation closely. Key words: Monochorionic diamniotic ; Fetal growth retardation; Pregnancy outcome; Prognosis