Twin Gestation and Neurodevelopmental Outcome in Extremely Low Birth Weight Infants

Abstract

Objective To compare the risk-adjusted incidence of death or neuro-developmental impairment at 18–22 months corrected age, between twin and singleton extremely low birth weight infants. Hypothesis Twin gestation is independently associated with increased risk of death or adverse neuro-developmental outcomes at 18–22 months corrected age in extremely low birth weight infants. Design/Methods Retrospective study of inborn extremely low birth weight infants (BW 401– 1000g) admitted to NICHD Neonatal Research Network units between 1997 and 2005, who either died or had follow-up data available at 18–22 months corrected age. Neuro-developmental impairment (NDI), the primary outcome variable, was defined as the presence of any one of the following: moderate or severe cerebral palsy, severe bilateral hearing loss needing amplification, bilateral blindness, Bayley Mental Developmental Index or Psychomotor Developmental Index of less than 70. Death was included with NDI as a composite outcome since it is a competing variable. Results were compared for both twins, twin A, twin B, same sex twins, unlike sex twins and singleton infants. Logistic regression analysis was done to control for demographic and clinical factors that were different among the groups. Results The cohort of infants who either died or were assessed for NDI consisted of 7,630 singleton infants and 1,376 twins. Logistic regression adjusting for clinical and socio-demographic risk factors showed an increased risk of death or NDI for twins as a group when compared with the singletons (OR-1.39, 95% CI- 1.19–1.63). On analyzing twin A and B separately as well, risk of death or NDI was increased in both twin A (OR-1.32, 95% CI- 1.09–1.59) and for twin B (OR-1.47, 95% CI- 1.21–1.78), when compared with singleton infants. Conclusions Twin gestation in ELBW infants is associated with an independent increased risk of death or NDI at 18–22 months corrected age, compared to ELBW singleton gestation infants. Both first and second born twins are at increased risk of death or NDI when compared to singleton ELBW infants.

Changes in Survival and Neonatal Morbidity in Infants with a Birth Weight of 750 g or Less

“…The majority of the SGA infants were of male gender, and from other studies it is known that female neonates have a better chance of survival compared to their male peers [28][29][30] . Interestingly male gender did not affect the survival of our SGA infants in a negative way.…”

“…Several studies have shown that a multiple pregnancy is a high risk situation resulting in a significantly higher prevalence of morbidity and poor survival [26,28] . 22.8% of our infants were part of a multiple pregnancy, which may have influenced outcome.…”

Re-Thinking Elective Single Embryo Transfer: Increased Risk of Monochorionic Twinning - A Systematic Review

“…Cognitive development is impaired in twins compared to singletons according to the Baley Scales of Infant Development Index [82,83] in preterm infants. There is consistent cognitive disadvantage among twins seen in population-based studies [84] .…”

Neurodevelopmental Outcomes of Triplets or Higher-Order Extremely Low Birth Weight Infants

“…We have previously shown that ELBW twins have a higher risk of death or neurodevelopmental handicap compared with singletons in the same birth-weight category. 6 The objective of the current study was to evaluate the comparative risk of death or neurodevelopmental handicap in higher-order multiples (triplets or higher order) compared with twins and singletons. The primary outcome of interest was death or neurodevelopmental impairment (NDI) at 18 to 22 months of age.…”