Neonatal complications and neurophysiological development in twins - a long-term follow-up study.

OBJECTIVES: To investigate the association between neonatal complications and neurophysiological development in twins at 18 and 48-60 months of age. METHODS: This was a secondary analysis of 841 Danish mono- and dichorionic diamniotic twins from a randomized controlled trial (PREDICT study), which included an assessment of the twin's neurophysiological development using the Ages and Stages Questionnaire (ASQ) that had been filled out by the parents at 18 and 48 or 60 months. The correlation within twin pairs was accounted for by the method of generalized estimating equation. Models were adjusted for maternal educational score and gestational age at delivery. RESULTS: ASQ data were available for 823 children at 18 months and 425 children at 48 or 60 months. Low maternal educational score and preterm delivery <34 weeks were associated with a lower ASQ score at 48-60 months (-15.4 points (95%CI -26.4; -4.5) and -13.2 points (95%CI -23.8; -2.5), respectively). Neonatal sepsis and a compound of intraventricular hemorrhage, retinopathy of prematurity and necrotizing enterocolitis (IVH/ROP/NEC) were associated with lower ASQ score at 18 months (-15.3 points (95%CI -28.1; -2.5) and -30.8 points (95%CI -59.5; -2.1), respectively). Children with IVH/ROP/NEC had a lower ASQ score at 48-60 months (-34.2 points (95%CI -67.9; -0.6)). The associations were not specific to only one ASQ domain. CONCLUSION: Several neonatal complications are associated with poorer neurophysiological development in twins during childhood, even after adjustment for gestational age at delivery.

Short- and long-term perinatal outcome in twin pregnancies affected by weight discordance.

INTRODUCTION: The objective was to investigate the association between chorionicity-specific intertwin birthweight discordance and adverse outcomes including long-term follow up at 6, 18, and 48-60 months after term via Ages and Stages Questionnaire. MATERIAL AND METHODS: In this secondary analysis of a cohort study (Oldenburg et al., n = 1688) and a randomized controlled trial (PREDICT study, n = 1045) twin pairs were divided into three groups according to chorionicity-specific birthweight discordance: <75th percentile, 75th-90th percentile and >90th percentile. Information on infant mortality, admittance to neonatal intensive care units, and gestational age at delivery was available for all pairs. Detailed neonatal outcomes were available for 656 pairs from PREDICT, of which 567 pairs had at least one Ages and Stages Questionnair follow-up. Logistic regression models were used for dichotomous outcomes. Ages and Stages Questionnair scores were compared using the method of generalized estimating equation to account for the correlation within twins. RESULTS: The 75th and 90th percentiles for birthweight discordance were 14.8 and 21.4% for monochorionic and 16.0 and 23.8% for dichorionic twins. After adjustment for small for gestational age and gender, birthweight discordance >75th and >90th percentile was associated with induced delivery <34 weeks [odds ratio 1.71 (95% confidence interval 1.11-2.65) and odds ratio 2.83 (95% confidence interval 1.73-4.64), respectively]. Discordance >75th-percentile was associated with an increased risk of infant mortality after 28 days [odds ratio 4.69 (95% confidence interval 1.07-20.45)] but not with major neonatal complications or with low mean Ages and Stages Questionnair scores at 6, 18, and 48-60 months after term. CONCLUSION: Chorionicity-specific intertwin birthweight discordance is a risk factor for induced preterm delivery and infant mortality, but not for lower scores for neurophysiological development at 6, 18, and 48-60 months.

Cytokines and the risk of preterm delivery in twin pregnancies.

OBJECTIVE: To estimate the association between cytokine levels in twin pregnancies and risk of spontaneous preterm delivery, including the effect of progesterone treatment. METHODS: This secondary analysis of a randomized placebo-controlled trial investigating the effect of progesterone treatment on preterm delivery in twin pregnancies included 523 women with available dried blood spot samples collected before treatment with progesterone (n=258) or placebo (n=265) and after 4-8 weeks of treatment. Samples were analyzed for cytokines using a sandwich immunoassay. Cytokine levels in spontaneous preterm delivery at 34-37 weeks of gestation and spontaneous preterm delivery before 34 weeks of gestation were compared with delivery at 37 weeks of gestation or more for placebo-treated women. The association between interleukin (IL)-8 and risk of spontaneous preterm delivery before 34 weeks of gestation was estimated further, including comparison according to treatment. Statistical analyses included Kruskal-Wallis test, Mann-Whitney U test, linear regression, and Cox regression analysis. RESULTS: We found a statistically significant association between IL-8 and spontaneous preterm delivery. At 23-33 weeks of gestation, the median IL-8 level was 52 pg/mL (interquartile range 39-71, range 19-1,061) for term deliveries compared with 65 pg/mL (interquartile range 43-88, range 14-584) for spontaneous preterm delivery at 34-37 weeks of gestation and 75 pg/mL (interquartile range 57-102, range 22-1,715) for spontaneous preterm delivery before 34 weeks of gestation (P<.001). Risk of spontaneous preterm delivery was associated with a large weekly increase in IL-8 (hazard ratio 2.0, 95% confidence interval [CI] 1.2-3.3). There was no effect of progesterone treatment on IL-8 levels. Levels of IL-8 at 18-24 weeks of gestation were associated with a cervix less than 30 mm (odds ratio 1.8, 95% CI 1.2-2.7). CONCLUSION: Risk of spontaneous preterm delivery before 34 weeks of gestation is increased in women with high IL-8 levels. Progesterone treatment does not affect IL-8 levels.