Evaluating 2 Year Outcome in Twins ≤ 30 Weeks Gestation at Birth: A Regional Perinatal Unit's Experience

Abstract

With improved technology in assisted reproductive medicine, there has been an absolute increase in the numbers of twin pregnancies with an associated increase in perinatal mortality and morbidity. This increase in perinatal mortality and morbidity is largely due to a higher incidence of delivering preterm as compared to singletons. Twin pregnancies have their unique complications that include abnormal placental communication and discordant growth which are associated with perinatal mortality and morbidity. The objectives of this study were two-fold: i) to determine if the morbidity/mortality outcome at 18–24 months corrected age seen in a cohort of twins born between 24–30 weeks gestation was significantly different as compared to singleton preterm infants of the same gestation; and ii) to determine and evaluate any differences between monochorionic (MC) and dichorionic (DC) twins. Twins 24–30 weeks gestation at birth born between 01/01/97–30/06/99 were identified and prospectively followed to 18–24 months corrected age (c.a.). They were matched with a singleton infant of the same gender and within 1 week of the same gestation. Obstetrical, neonatal and neurodevelopmental data were gathered and analyzed. The primary outcome was death or the presence of a severe neurodevelopmental deficit at 18–24 months corrected age. Of the 56 sets of twins identified, 52 sets were followed prospectively with 101 infants available for matching. In this cohort, twin pregnancies had a lower incidence of pregnancy-induced hypertension and premature rupture of membranes than singletons (p < 0.05). The two groups were comparable in neonatal characteristics. The incidence of death or severe disability was 29.7% in twins vs. 22.8% in singletons (p = 0.337, Fisher's exact test). The major area of deficit was in the cognitive category for both groups, 9.9% vs. 7.9% respectively. MC twins made up 35.6%; DC twins 64.4%. Twin to twin transfusion syndrome (TTTS) occurred in 6.9%. Discordant growth occurred more frequently in MC pregnancies (p = 0.016). MC twins tended to be more premature, lower in birth weight, and experience neonatal morbidity in the form of patent ductus arteriosus and sepsis (p < 0.05) as compared to DC twins. However, the primary outcome of death or severe neurodevelopmental deficit at 18–24 months c.a. was not significantly different between the two groups, 38.9% (MC) vs. 24.6% (DC), (p = 0.173, Fisher's exact test). Neurodevelopmental morbidity or mortality in twins with TTTS was 42%. Mortality and severe neurodevelopmental morbidity were not significantly higher in twins as compared to singletons in this cohort. However, the trend is slightly higher in twins, which may have clinical significance. Though not statistically significant, the incidence of 38.9% in adverse outcome with MC twins may be clinically significant. With the number of twins steadily increasing, further monitoring is required to determine future directions in intervention and research. Early recognition of monochorionicity remains essential to optimize care and neurodevelopment for these infants.

Mortality of twin and singleton livebirths under 30 weeks' gestation: a population-based study

“…Alternatively, perhaps the twins with congenital anomalies had more antenatal or early pregnancy loss, or that the reasons why singletons and twins go into preterm labour may themselves be different, which may also help to account for the unexpectedly different rates of malformation in the two groups. Monochorionic twins are known to be at higher risk during the pregnancy, and it has been suggested (from unit-based data) that they suffer more postnatal deaths9 compared with dichorionic twins, but our observations, confined to liveborn twins, have failed to confirm this.…”

Neurodevelopmental Outcomes of Twins Compared With Singleton Children: A Systematic Review

“…The incidence of multiple births is rising because of increased use of assisted reproductive technologies (Asztalos et al, 2001; Hamilton et al, 2006). Multiple pregnancies have risen to account for about 3% of all births, yet they account for 15% of all perinatal mortality (Acosta-Rojas et al, 2007; Giuffre et al, 2012).…”

Neurodevelopmental Outcome Among Multiples and Singletons: A Regional Neonatal Intensive Care Unit's Experience in Turkey

“…Over the past two decades, there has been a regular increase in the incidence of preterm births all over the world, with a range of 7–13% (Hamilton et al, 2006). Most of this increase was due to an increase in multiple gestations because of the use of assisted reproductive medicine (Asztalos et al, 2001; Klebanoff & Keim, 2011; Shinwell, 2002). Currently, 3–4.5% of all births are multiple births (Martin et al, 2008).…”