Yumi Kono

Outcomes of Infants Born at 22 and 23 Weeks’ Gestation

OBJECTIVE: To provide instructive information on death and neurodevelopmental outcomes of infants born at 22 and 23 weeks’ gestational age. METHODS: The study cohort consisted of 1057 infants born at 22 to 25 weeks in the Neonatal Research Network, Japan. Neurodevelopmental impairment (NDI) at 36 to 42 months’ chronological age was defined as any of the following: cerebral palsy, hearing impairment, visual impairment, and a developmental quotient <70. A systematic review was performed by using databases of publications of cohort studies with neonatal and neurodevelopmental outcomes at 22 and 23 weeks. RESULTS: Numbers and incidences (%) of infants with death or NDI were 60 (80%) at 22 weeks and 156 (64%) at 23 weeks. In logistic regression analysis, gestational ages of 22 weeks (odds ratio [OR]: 5.40; 95% confidence interval [CI]: 2.48–11.76) and 23 weeks (OR: 2.14; 95% CI: 1.38–3.32) were associated with increased risk of death or NDI compared with 24 weeks, but a gestational age of 25 weeks (OR: 0.65; 95% CI: 0.45–0.95) was associated with decreased risk of death or NDI. In the systematic review, the medians (range) of the incidence of death or NDI in 8 cohorts were 99% (90%–100%) at 22 weeks and 98% (67%–100%) at 23 weeks. CONCLUSIONS: Infants born at 22 and 23 weeks’ gestation were at higher risk of death or NDI than infants at born at 24 weeks. However, outcomes were improved compared with those in previous studies. There is a need for additional discussions on interventions for infants born at 22 or 23 weeks’ gestation.

Neonatal correlates of adverse outcomes in very low‐birthweight infants in the NICU Network

Background:  The aim of the present study was to explore the relationships among neonatal morbidity, interventions and death or adverse neurodevelopmental outcomes in very low‐birthweight (VLBW) infants.

Prolonged maternal magnesium administration and bone metabolism in neonates

BACKGROUND Magnesium sulfate (MgSO(4)) has been used as a tocolytic agent in cases of refractory preterm labor. Prolonged maternal administration of MgSO(4) may induce bone demineralization in the neonate. However, the effects of MgSO(4) on serum biochemistry related to bone metabolism in neonates remain unclear. AIM To assess the effects of prolonged maternal administration of MgSO(4) on fetuses and neonates. STUDY DESIGN This retrospective case-control study examined 167 neonates. Cases comprised 58 neonates whose mothers had received intravenous MgSO(4) administration for >5 days. Neonatal serum levels of magnesium (Mg), calcium (Ca), phosphorus (P) and alkaline phosphatase (ALP) were reviewed. We also investigated whether subject neonates showed appearance of osteopenia at the metaphyseal lines on radiography at birth. RESULTS Mean serum Mg and P levels were significantly higher, and Ca levels were significantly lower, in cases than in controls at birth. Mean serum ALP level was 1188.5IU/l in cases, significantly higher than that in controls at birth. Bone abnormalities were noted on radiography in 2 subjects. By 3 weeks old, serum ALP levels did not differ significantly between cases and controls. Logistic regression analysis revealed maternal administration of MgSO(4) and multiple pregnancies were significantly related to serum ALP level in neonates at birth. CONCLUSION Prolonged maternal administration of MgSO(4) significantly affects neonatal serum biochemistry related to bone metabolism. Potential long-term adverse effects on neonates and how Mg affects fetal bone metabolism in utero need to be investigated in future studies.

Impact of being small-for-gestational age on survival and long-term outcome of extremely premature infants born at 23-27 weeks' gestation.

Abstract Aim: To evaluate factors affecting survival and long-term outcome of extremely premature infants and to determine whether small for gestational age (SGA) status is an additional risk factor. Methods: Survival was analyzed in 193 infants born between 23 and 27 weeks of gestational age (GA) and compared between SGA (n=43) and appropriate for gestational age (AGA) infants. Long-term outcome was assessed in 123 infants at six years of chronological age by neurological evaluation and cognitive tests. Results: The long-term survival rates were 72.1% for SGA and 84.0% for AGA infants. Significant independent factors affecting survival were GA (OR 1.79 for one week advance, 95% CI 1.36–2.34) and SGA (OR 0.42, 95% CI 0.18–0.997) in comparison with AGA. There were no significant differences in rates of cerebral palsy or mental retardation, 12.0% and 24.0% in SGA, 14.3% and 17.3% in AGA, respectively. Fifty-two percent of SGA and 70% of AGA infants had intact long-term outcome. The perinatal factor found to affect the intact long-term outcome was RDS with surfactant therapy (OR 0.17, 95% CI 0.07–0.45). Conclusion: SGA status as well as short gestation had significant effects on survival. Respiratory complications after birth had a larger detrimental effect on long-term outcome than whether the infant was SGA or AGA.

Outcomes of very-low-birthweight infants at 3 years of age born in 2003-2004 in Japan

Background:  The aim of this study was to describe and compare neurodevelopmental outcomes with birthweight (BW) groups at 250‐g intervals of very‐low‐birthweight (VLBW) infants at 3 years of age in a multicenter cohort in Japan.

Developmental assessment of VLBW infants at 18 months of age: A comparison study between KSPD and Bayley III.

AIM To assess the developmental characteristics of very low-birth-weight (VLBW) infants using the Kyoto Scale of Psychological Development (KSPD) and to compare with those using the Bayley Scales, third edition (Bayley III). METHODS KSPD and Bayley III were performed on 124 Japanese VLBW infants at 18months of corrected age at a 2-week interval by trained psychologists. The relationships between KSPD and Bayley III in corresponding pairs: Cognitive-Adaptive (C-A) developmental quotient (DQ) and cognitive composite (Cog) scores, Language-Social (L-S) DQ and language composite (Lang) scores, and Postural-Motor (P-M) DQ and motor composite (Mot) scores were analyzed. RESULTS The means [SD] of C-A DQ, L-S DQ, P-M DQ, and overall DQ of KSPD were 94 [15], 90 [17], 89 [15], and 93 [14], respectively. The means [SD] of the Cog, Lang, and Mot scores of Bayley III were 96 [13], 84 [12], and 91 [12], respectively. The DQ of KSPD strongly correlated with the corresponding composite score of Bayley III; Spearman rank correlations between the Cog score and C-A DQ, the Lang score and L-S DQ, and the Mot score and P-M DQ were 0.65, 0.71 and 0.55, respectively. The selected cut-off of the Cog score of <85 accurately identified development delay, defined by KSPD, with sensitivity of 100% and specificity of 85%. CONCLUSION Although absolute value of the Bayley III score may not represent the degree of impairment, the developmental characteristics on KSPD well correlated with those on Bayley III. The developmental outcomes of Japanese VLBW infants were verified by the two tests.

Developmental characteristics of very low-birthweight infants at 18 months' corrected age according to birthweight.

Background: The objective of the present study was to describe developmental profiles of very low‐birthweight (VLBW) infants compared by birthweight, because those of infants with birthweight <750 g might be different from other VLBW infants.

Gut hormone profiles in preterm and term infants during the first 2 months of life.

Abstract Aim: To investigate changes of gut hormones in term and preterm infants in the first 2 months after birth, as the role and relationships of gut hormones in premature infants has not been well elucidated. Methods: In 29 preterm and five term infants, fasting serum concentrations of leptin, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), peptide YY (PYY), pancreatic polypeptide, insulin, amylin, and ghrelin were measured using a bead array system. Results: Serum leptin concentration soon after birth showed a positive correlation with gestational week in all infants (r=0.623, p<0.01). Serum leptin level rapidly decreased in all infants. In preterm infants, serum GLP-1 levels at birth showed negative correlations with gestational week (r=–0.447, p=0.02). Serum GIP, GLP-1, and PYY levels increased after birth and were persistently high until 10 weeks of life. Conclusion: Serum concentrations of different gut hormones changed postnatally in their specific ways in preterm infants.

The Effects of Antenatal Corticosteroids on Short- and Long-Term Outcomes in Small-for-Gestational-Age Infants.

Aim: To evaluate the effect of antenatal corticosteroids (ANS) on short- and long-term outcomes in small-for-gestational age (SGA) infants. Methods: A retrospective database analysis was performed. A total of 1,931 single infants (birth weight <1,500 g) born at a gestational age between 22 weeks and 33 weeks 6 days who were determined to be SGA registered in the Neonatal Research Network Database in Japan between 2003 and 2007 were evaluated for short-term outcome and long-term outcome. Results: ANS was administered to a total of 719 infants (37%) in the short-term outcome evaluation group and 344 infants (36%) in the long-term outcome evaluation group. There were no significant differences between the ANS group and the no-ANS group for primary short-term outcome (adjusted odds ratio (OR) 0.73; 95% confidence interval (CI) 0.45-1.20; P-value 0.22) or primary long-term outcome (adjusted OR 0.69; 95% CI 0.40-1.17; P-value 0.17). Conclusions: Our results show that ANS does not affect short- or long-term outcome in SGA infants when the birth weight is less than 1500 g. This study strongly suggests that administration of ANS resulted in few benefits for preterm FGR fetuses.

Impact of chorioamnionitis on short- and long-term outcomes in very low birth weight preterm infants: the Neonatal Research Network Japan

Abstract Objective: To evaluate the short- and long-term outcomes among very low birth weight (VLBW) preterm infants after histologic chorioamnionitis (HCA). Methods: We performed a retrospective analysis of 5849 single infants (birth weight <1500 g) born at a gestational age between 22 + 0 and 33 + 6 weeks. Clinical data were obtained from the Neonatal Research Network Japan between 2003 and 2007. Multivariable logistic regression analyses were performed to assess the effect of HCA on short- and long-term outcome. Results: According to logistic regression analysis, HCA was associated with lower incidence of respiratory distress syndrome (odds ratio [OR] = 0.54; p < 0.001), increased chronic lung disease (OR = 1.68; p < 0.001) and sepsis (OR = 1.71; p < 0.001) and as a short-term outcomes. There was no significant association with intraventricular hemorrhage (OR = 1.11; p = 0.33), periventricular leukomalacia (OR = 1.07; p = .070) and death before discharge (OR = 0.97; p = 0.084). HCA was associated with increased home oxygen therapy (OR = 3.09; p < 0.001), but not with cerebral palsy (CP; OR = 0.91; p = 0.63), develop quotient < 70 (OR = 1.27; p = 0.17), visual impairment (OR = 1.08; p = 0.77), severe hearing impairment (OR = 1.28; p = 0.62) and death (OR = 0.98; p = 0.91) before three years of age. Conclusions: In this retrospective population-based study in Japan, HCA was not a risk factor for death, neurodevelopmental impairment and CP in VLBW three-year-old preterm infants.