Effect of Chorionicity， Gestational Age at Birth and Birth Weight Discordance on Neonatal Outcomes in Twin Pregnancies / 中山大学学报(医学科学版)

ObjectiveTo investigate the effect of chorionicity， gestational age at birth and birth weight discordance on neonatal outcomes in twin pregnancies. MethodsWe conducted a population-based retrospective study of monochorionic diamniotic （MCDA） twin pregnancies and dichorionic diamniotic （DCDA） twin pregnancies who were admitted in the First Affiliated Hospital， Sun Yat-sen University from January 2015 to December 2020. A total of 1504 live-born twins were included， with 386 cases in MCDA group and 1118 cases in DCDA groups， respectively. The comparison of neonatal outcomes between MCDA and DCDA twins was performed using t-test， Wilcoxon rank sum test， Chi-square test or Fisher’s exact test. Logistic regression was performed to evaluate the effects of chorionicity， gestational age at birth， birth weight discordance and sex on neonatal outcomes. There were 168 live-born twins affected by inter-twin birth weight discordance≥25%， with 96 cases in MCDA group and 72 cases in DCDA groups， respectively. Logistic regression was performed to evaluate the effects of chorionicity， gestational age at birth， birth weight light or heavy （small twin or large twin） of the twin and sex on neonatal outcomes. ResultsAmong the 1 504 newborns， gestational age at birth was lower in MCDA group compared with DCDA group （P = 0.000）， and the degree of birth weight discordance was higher in MCDA group than that of the DCDA group （P = 0.001）. Birth asphyxia， respiratory distress syndrome （RDS）， bronchopulmonary dysplasia （BPD）， and sepsis were more frequency in MCDA group compared with DCDA group （P = 0.000， P = 0.000， P = 0.000， P = 0.000）. Low gestational age at birth was an independent risk factor for birth asphyxia， RDS， BPD， sepsis， necrotizing enterocolitis （NEC）≥stageⅡ， acute kidney injury （AKI）， retinopathy of prematurity （ROP）， and neonatal death respectively （P = 0.000， P = 0.000， P = 0.000， P = 0.000， P = 0.011， P = 0.000， P = 0.000， P = 0.000）. High degree of birth weight discordance was an independent risk factor for birth asphyxia， RDS， BPD， sepsis and ROP respectively （P = 0.045， P = 0.000， P = 0.000， P = 0.004， P = 0.017 ）. Chorionicity was not an independent risk factor for neonatal morbidity and death （P > 0.05）. Among the 168 twins with birth weight discordance ≥25%， low gestational age at birth was an independent risk factor for birth asphyxia， RDS， BPD， sepsis and ROP， respectively （P = 0.000， P = 0.000， P = 0.000， P = 0.000， P = 0.000）； small twin was an independent risk factor for birth asphyxia and BPD， respectively （ P = 0.013， P = 0.001）； chorionicity was not an independent risk factor for neonatal morbidity （P > 0.05）. ConclusionChorionicity was not an independent risk factor for adverse neonatal outcome in twin births. Low gestational age at birth and high degree of birth weight discordance were independent risk factor for adverse neonatal outcome in twin births. Small twins had increased risk of adverse neonatal outcome in twins with birth weight discordance ≥25%.

Impact of assisted reproductive technology on birth weight discordance in twins / 中国当代儿科杂志

OBJECTIVES@#To explore the association between assisted reproductive technology (ART) and birth weight discordance in twins (BWDT).@*METHODS@#A retrospective analysis was conducted on twin infants born between January 2011 and December 2020 at the Third Affiliated Hospital of Guangzhou Medical University, with complete basic birth data. The impact of ART on the occurrence of BWDT was identified by the multivariate logistic regression analysis.@*RESULTS@#A total of 3 974 pairs of twins were included, with 1 431 conceived naturally and 2 543 through ART. Neonates in the ART group had higher birth weights than those in the naturally conceived group (P<0.001). The incidence of BWDT was lower in the ART group compared to the naturally conceived group (16.17% vs 21.09%, P<0.001). The multivariate logistic regression analysis, adjusting for confounding factors such as maternal age, parity, pre-pregnancy body mass index, gestational diabetes, hypothyroidism, gestational age, and chorionic properties, showed no significant difference in the risk of BWDT between the ART and naturally conceived groups (P>0.05).@*CONCLUSIONS@#ART is not associated with the risk of BWDT.

Value of ultrasonography in predicting the birth weight discordance of twin pregnancy / 上海交通大学学报（医学版）

Objective·To identify the relationship between the estimated fetal weight (EFW) discordance and birth weight (BW) discordance, and evaluate the accuracy of ultrasonography in predicting birth weight discordance (△BW) of twin pregnancy. Methods·The ultrasound was used to detect the growth of twins at different gestational weeks and the data were analyzed to compare the difference between EFW discordance (△EFW) and ?BW. Results·About 15.9 percent of twins (totally 277 cases) had severe △BW (△BW ≥20%) in our study, and the percentages of dichorionic-diamniotic twin (DCDA) and monochorionic-diamniotic twin (MCDA) were 68.2% and 31.8%, respectively (P>0.01). Compared with △EFW in other gestational weeks,△EFW last time before parturition was most consistent of △BW. Furthermore, the negative predictive value of MCDA was highest (94%) at 22-24 gestational weeks. Conclusion·Twin △BW was relatively better predicted by △EFW last time before parturition. Twin pregnancy without severe △EFW (△EFW<20%), especially MCDA with △EFW<20% at 22-24 weeks, had low probability of selective intrauterine growth restriction in the future.

The Relationship between Maternal Age at Birth and Intertwin Birth Weight Discordance in Korea

PURPOSE: To compare the relationship between intertwin birth weight discordance and maternal age at birth. METHODS: There were 51,726 pairs of twins born from 2007 to 2014 according to the birth certificate data of Korea Statistics (3,701,806 births). The data were excluded due to extra marital births, home births, and teenage births. Birth weight discordance rate (%) was calculated according to the following formula: (larger birth weight - smaller birth weight)/(birth weight of the larger twin) ×100. The odds ratio of intertwin birth weight discordance rate (≥25%) in maternal age at birth was calculated by logistic regression adjusted by the year of birth, gestational age, maternal education, infantile gender and paternal age. RESULTS: The mean birth weight of the heavier twin and that of the lighter twin were 2.536 kg and 2.254 kg, respectively. The mean birth weight difference of intertwins was 0.282 kg. The mean birth weight discordance rate by maternal age was 10.5 percent for maternal ages between 20 and 29 years, 11.0 percent for between 30 and 34 years, and 11.4 percent for 35 years and older. The frequency of birth weight discordance level of ≥25 percent increased as the maternal age increased. The rate of birth weight discordance (≥25%) was 7.7 percent for maternal ages between 20 and 29 years, 8.3 percent for between 30 and 34 years, and 8.7 percent in for 35 years and older. Compared with women from 20 to 29 years of age, the odds ratio of ≥25 percent discordance was 1.094 (95% confidence interval: 1.005~1.190) for 30 to 34 years, and 1.164 (1.401~1.301) for 35 years and older. The odds ratio of ≥25 percent discordance for the different-sexed twins was higher than that of the same-sexed twins in overall maternal age groups of 20 to 29 years, 30 to 34 years, and 35 years and older. CONCLUSION: The risk of birth weight discordance level of ≥25 percent was associated with the older maternal age. More research is required to understand the risk factors of intertwin birth weight discordance for older women.

The Discordance of Intra-twin Birth Weight by Infantile Gender and Birth Order in Korea; 2008-2013 / 대한주산의학회잡지

PURPOSE: To investigate the incidence of intra-twin birth weight discordance and its association with infantile gender and birth order. METHODS: We used the data of birth from 2008 to 2013 of Korea Statistics (38,140 pairs of twins). Adjusted logistic regression analyses were performed to describe the birth weight discordance (> or =25%) according to infantile gender and birth order (twin A: 1st, twin B: 2nd). Birth weight discordance was calculated as 100 x (birth weight difference/birth weight of the heavier twin). RESULTS: Twin A (mean 2.431 kg) was heavier than twin B (mean 2.359 kg), and the weight difference was 0.281 kg on average. Overall incidence of birth weight discordance was 8.3 percent. The incidence of discordance was 8.8 percent among unlike-sexed pairs and 8.0 percent among like-sexed pairs. Twins with birth weight A> or =B (10.2 percent) showed higher incidence of discordance than twins with birth weight A or =B) as compared to like-sexed twins (female-female) with birth weight (A