Risk Factors for Retinopathy of Prematurity in the Netherlands: A Comparison of Two Cohorts.

INTRODUCTION: Retinopathy of prematurity (ROP) remains an important cause for preventable blindness. Aside from gestational age (GA) and birth weight, risk factor assessment can be important for determination of infants at risk of (severe) ROP. METHODS: Prospective, multivariable risk-analysis study (NEDROP-2) was conducted, including all infants born in 2017 in the Netherlands considered eligible for ROP screening by pediatricians. Ophthalmologists provided data of screened infants, which were combined with risk factors from the national perinatal database (Perined). Clinical data and potential risk factors were compared to the first national ROP inventory (NEDROP-1, 2009). During the second period, more strict risk factor-based screening inclusion criteria were applied. RESULTS: Of 1,287 eligible infants, 933 (72.5%) were screened for ROP and matched with the Perined data. Any ROP was found in 264 infants (28.3% of screened population, 2009: 21.9%) and severe ROP (sROP) (stage ≥3) in 41 infants (4.4%, 2009: 2.1%). The risk for any ROP is decreased with a higher GA (odds ratio [OR] 0.59 and 95% confidence interval [CI] 0.54-0.66) and increased for small for GA (SGA) (1.73, 1.11-2.62), mechanical ventilation >7 days (2.13, 1.35-3.37) and postnatal corticosteroids (2.57, 1.44-4.66). For sROP, significant factors were GA (OR 0.37 and CI 0.27-0.50), SGA (OR 5.65 and CI 2.17-14.92), postnatal corticosteroids (OR 3.81 and CI 1.72-8.40), and perforated necrotizing enterocolitis (OR 7.55 and CI 2.29-24.48). CONCLUSION: In the Netherlands, sROP was diagnosed more frequently since 2009. No new risk factors for ROP were determined in the present study, apart from those already included in the current screening guideline.

Survival and causes of death in extremely preterm infants in the Netherlands.

OBJECTIVE: In the Netherlands, the threshold for offering active treatment for spontaneous birth was lowered from 25+0 to 24+0 weeks' gestation in 2010. This study aimed to evaluate the impact of guideline implementation on survival and causes and timing of death in the years following implementation. DESIGN: National cohort study, using data from the Netherlands Perinatal Registry. PATIENTS: The study population included all 3312 stillborn and live born infants with a gestational age (GA) between 240/7 and 266/7 weeks born between January 2011 and December 2017. Infants with the same GA born between January 2007 and December 2009 (N=1400) were used as the reference group. MAIN OUTCOME MEASURES: Survival to discharge, as well as cause and timing of death. RESULTS: After guideline implementation, there was a significant increase in neonatal intensive care unit (NICU) admission rate for live born infants born at 24 weeks' GA (27%-69%, p<0.001), resulting in increased survival to discharge in 24-week live born infants (13%-34%, p<0.001). Top three causes of in-hospital mortality were necrotising enterocolitis (28%), respiratory distress syndrome (19%) and intraventricular haemorrhage (17%). A significant decrease in cause of death either complicated or caused by respiratory insufficiency was seen over time (34% in 2011-2014 to 23% in 2015-2017, p=0.006). CONCLUSIONS: Implementation of the 2010 guideline resulted as expected in increased NICU admissions rate and postnatal survival of infants born at 24 weeks' GA. In the years after implementation, a shift in cause of death was seen from respiratory insufficiency towards necrotising enterocolitis and sepsis.

[A neonate with anaemia of prematurity: zinc protoporphyrin identifies iron deficiency anaemia without iron deficiency]. / Een prematuur met anemie: zinkprotoporfyrine identificeert ijzergebreksanemie zonder ijzergebrek.

Anaemia is a common problem in premature infants and is generally easy to treat with iron supplementation. If the anaemia persists despite appropriate correction of deficiencies, more extensive evaluation is required. We describe a case of a premature male infant with a production-deficient anaemia without metabolic deficiencies, eventually identified as anaemia of prematurity. This type of anaemia is commonly diagnosed but its highly variable and complex aetiology and phenotype are often poorly understood. A probable explanation for the anaemia of prematurity in this case was a transient iron incorporation defect, identifiable by high levels of zinc protoporphyrin.

Substandard care in delivery-related asphyxia among term infants: prospective cohort study.

OBJECTIVE: To assess substandard care factors in the case of delivery-related asphyxia. DESIGN: Prospective cohort study. SETTING: Catchment area of the Neonatal Intensive Care Unit (NICU) of the University Medical Center Utrecht; a region in the middle of the Netherlands covering 13% of the Dutch population. POPULATION: Term infants, without congenital malformations, who died intrapartum or were admitted to the Neonatal Intensive Care Unit due to asphyxia. METHODS: During a two-year period, cases were prospectively collected and audited by an expert panel. MAIN OUTCOME MEASURES: Substandard care factors. RESULTS: 37 735 term infants without congenital malformations were born. There were 19 intrapartum deaths, and 89 NICU admissions of which 12 neonates died. In 63 (58%) cases a substandard care factor was identified that was possibly (n= 47, 43%) or probably (n= 16, 15%) related to perinatal death or NICU admission. In primary care, substandard care factors were mainly the low frequency of examination during labor and delay in referral to secondary care. In secondary care, misinterpretation of cardiotocography and failure to respond adequately to clinical signs of fetal distress were the most common substandard care factors. CONCLUSIONS: Substandard care is present in a substantial number of cases with delivery-related asphyxia resulting in perinatal death or NICU admission. Improving the organization of obstetric care in the Netherlands as well as training of obstetric caregivers might reduce adverse outcomes.

Perinatal mortality and severe morbidity in low and high risk term pregnancies in the Netherlands: prospective cohort study.

OBJECTIVE: To compare incidences of perinatal mortality and severe perinatal morbidity between low risk term pregnancies supervised in primary care by a midwife and high risk pregnancies supervised in secondary care by an obstetrician. DESIGN: Prospective cohort study using aggregated data from a national perinatal register. SETTING: Catchment area of the neonatal intensive care unit (NICU) of the University Medical Center in Utrecht, a region in the centre of the Netherlands covering 13% of the Dutch population. PARTICIPANTS: Pregnant women at 37 weeks' gestation or later with a singleton or twin pregnancy without congenital malformations. MAIN OUTCOME MEASURES: Perinatal death (antepartum, intrapartum, and neonatal) or admission to a level 3 NICU. RESULTS: During the study period 37 735 normally formed infants were delivered at 37 weeks' gestation or later. Sixty antepartum stillbirths (1.59 (95% confidence interval 1.19 to 1.99) per 1000 babies delivered), 22 intrapartum stillbirths (0.58 (0.34 to 0.83) per 1000 babies delivered), and 210 NICU admissions (5.58 (4.83 to 6.33) per 1000 live births) occurred, of which 17 neonates died (0.45 (0.24 to 0.67) per 1000 live births). The overall perinatal death rate was 2.62 (2.11 to 3.14) per 1000 babies delivered and was significantly higher for nulliparous women compared with multiparous women (relative risk 1.65, 95% confidence interval 1.11 to 2.45). Infants of pregnant women at low risk whose labour started in primary care under the supervision of a midwife had a significant higher risk of delivery related perinatal death than did infants of pregnant women at high risk whose labour started in secondary care under the supervision of an obstetrician (relative risk 2.33, 1.12 to 4.83). NICU admission rates did not differ between pregnancies supervised by a midwife and those supervised by an obstetrician. Infants of women who were referred by a midwife to an obstetrician during labour had a 3.66 times higher risk of delivery related perinatal death than did infants of women who started labour supervised by an obstetrician (relative risk 3.66, 1.58 to 8.46) and a 2.5-fold higher risk of NICU admission (2.51, 1.87 to 3.37). CONCLUSIONS: Infants of pregnant women at low risk whose labour started in primary care under the supervision of a midwife in the Netherlands had a higher risk of delivery related perinatal death and the same risk of admission to the NICU compared with infants of pregnant women at high risk whose labour started in secondary care under the supervision of an obstetrician. An important limitation of the study is that aggregated data of a large birth registry database were used and adjustment for confounders and clustering was not possible. However, the findings are unexpected and the obstetric care system of the Netherlands needs further evaluation.