Is Growth-Discordance in Twins a Substantial Risk Factor in Adverse Neonatal Outcomes?

Abstract

To evaluate whether growth discordance is an independent risk factor in the neonatal outcome of the smaller twin, all medical records of twin pregnancies delivered between 26 and 41 weeks during a 5-year period (January 2004–December 2008) were reviewed. Among the 49 selected twins, weight discordance was 15–20% in 7 infants, 21–30% in 16 infants, 31–40% in 16 infants and > 40% in 10 infants. No significant differences between the four groups were found with regards to obstetric complications and neonatal disease. Occurrence of birthweight below the 10th percentile and rate of admission to the neonatal intensive care unit significantly increased as intra-pair birthweight difference increased (p = .03). The > 40% discordant group had a significantly lower gestational age (p = .03), lower birthweight (p = .007) and a significantly higher mortality rate (4/10 versus 3/39 p = .04) in comparison with the other discordant groups. Multiple logistic regression analysis showed that birthweight was the single independent and consistent factor associated with elevated risks of mortality. For every 250 g increase in birthweight, the risk for mortality decreased by about 84% [RR 0.16(CI 0.00-0.70)]. Gestational age was the most reliable predictor for major neonatal complications. For every 1-week increase in gestational age a significant decreased risk for all outcomes was found. Discordance alone should not be considered as a predictor for adverse neonatal outcome. Neonatal outcome in discordant twins appears to be related to gestational age and birthweight rather than to the degree of discordance.

First-trimester growth discordance and adverse pregnancy outcome in dichorionic twins

“…With the increasing prevalence of twins over the last two decades and the disproportionate burden of neonatal morbidity and mortality in twins, a large body of research has been dedicated to identifying predictors of adverse outcomes in this population. Birth‐weight discordance has been correlated to perinatal morbidity and mortality, especially when associated with fetal growth restriction and low birth weight. Since data from singletons suggest that first‐trimester fetal growth is predictive of neonatal outcome, the impact of first‐trimester size discordance in twins is also of interest, but previous studies have presented conflicting data on this association.…”

The Impact of Twin Birth on Early Neonatal Outcomes

“…In the study by Amaru et al, they considered all twins with BW discordance more than 20%, reporting no increase in mortality. In the study by Frezza et al, 22 more than 40% BW discordant group had a significantly higher rate of mortality when compared with the other discordant groups. In our study, moderate (between 20 and 40%) and severe (>40%) BW discordances were significantly related to longer LOS, need for transfusion, hypoglycemia but no association with abnormal cUS findings was observed; babies with severe BW discordance showed an increased risk of death at the univariate analysis, which was not confirmed at the multivariate analysis.…”

“…Recently, the adverse role of intertwin BW discordance, as risk factor for neonatal morbidities and mortality, has been emphasized. [19][20][21][22][23][24] According to Vergani et al, 36 BW discordance is an independent predictor of neonatal mortality or major morbidity after correcting for GA. This was not the case in the study by Amaru et al 23 in which the authors stated that discordance was not an independent risk factor for neonatal death but appeared to increase only the risk of some adverse perinatal outcomes.…”

“…[18][19][20][21] Recently, the adverse role of intertwin BW discordance (occurring in 15-25% of twin pregnancies) has been highlighted and severe BW discordance has been associated with increased mortality. 19,[22][23][24] However, there is no universal agreement on to what extent the threshold for clinically significant intertwin BW discordance correlates to an increased risk of neonatal morbidity and mortality.…”

Blood Flow Changes in Dichorionic Twins With Growth Discordance

“…However, in the literature different data may be found. Frezza et al (2011) evaluated whether growth discordance is an independent risk factor in the neonatal outcome of the smaller twin. No significant differences between the four groups of different discordance were found with regard to obstetric complications and neonatal diseases.…”