Paula Haataja

Cerebral Palsy Among Children Born Moderately and Late Preterm

OBJECTIVE: To compare the incidence of and risk factors for cerebral palsy (CP) in moderately preterm (MP) (32+0–33+6 weeks) and late preterm (LP) (34+0–36+6 weeks) infants with those in very preterm (VP) (<32+0 weeks) and term infants (≥37 weeks). METHODS: The national register study included all live-born infants in Finland from 1991 to 2008. Infants who died before the age of 1 year, had any major congenital anomaly, or had missing data were excluded. A total of 1 018 302 infants were included in the analysis and they were analyzed in 4 subgroups (VP, MP, LP, and term) and 3 time periods (1991–1995, 1996–2001, and 2002–2008). RESULTS: By the age of 7 years, 2242 children with CP were diagnosed (0.2%). CP incidence was 8.7% in the VP, 2.4% in the MP, 0.6% in the LP, and 0.1% in the term group. The risk of CP was highest in the study period 1991–1995 in all groups. Factors predictive of an increased CP risk in the MP and LP groups included resuscitation at birth (odds ratio 1.60; 95% CI 1.01–2.53 and 1.78; 1.09–2.90), antibiotic treatment during the first hospitalization (1.63; 1.08–2.45 and 1.67; 1.13–2.44), 1-minute Apgar score <7 (1.70; 1.15–2.52 and 1.80; 1.21–2.67) and intracranial hemorrhage (7.18; 3.60–14.3 and 12.8; 5.58–29.2). CONCLUSIONS: The incidence of CP is higher in LP and MP infants compared with term infants. There is a nonlinear decrease in incidence over time and with increasing gestational age.

Asthma and atopic dermatitis after early-, late-, and post-term birth

To assess the incidence and risk factors of asthma and atopic dermatitis by seven years of age after early‐term (ET) (37+0‐38+6 weeks), full‐term (FT) (39+0‐40+6 weeks), late‐term (LT) (41+0‐41+6 weeks), and especially post‐term (PT) (≥42 weeks) birth.

The incidence and risk factors of epilepsy in children born preterm: A nationwide register study

OBJECTIVES The aim was to compare the incidence of epilepsy between very preterm (VP) (<32+0 weeks), moderately preterm (MP) (32+0-33+6 weeks), late preterm (LP) (34+0-36+6 weeks) and term infants (≥37 weeks) and to establish and compare risk factors of epilepsy in these groups. METHODS The national register study included all live born infants in Finland in 1991-2008. Excluding infants with missing gestational age, a total of 1,033,349 infants were included in the analysis and they were analyzed in four subgroups (VP, MP, LP and term) and three time periods (1991-1995, 1996-2001 and 2002-2008). RESULTS 5611 (0.54%) children with epilepsy were diagnosed. The incidence of epilepsy was 2.53% in the VP, 1.08% in the MP, 0.75% in the LP and 0.51% in the term group. Intracranial hemorrhage (OR 3.48; 95% CI 2.47-4.89) and convulsions in the neonatal period (OR 13.4; 95% CI 10.2-17.6) were associated with an increased risk of epilepsy. Compared to the term group, preterm birth (VP OR 4.59; 95% CI 3.79-5.57, MP 1.97; 1.48-2.63, LP 1.44; 1.25-1.68) was associated with an increased risk of epilepsy after adjusting for maternal, pregnancy, delivery and sex variables. CONCLUSIONS The incidence of epilepsy decreased by advancing gestational age at birth and preterm birth predicted an increased risk of epilepsy in childhood. Intracranial hemorrhage and neonatal convulsions were strongly associated with an increased risk of epilepsy.

Visual and Hearing Impairments After Preterm Birth

In this large national register study, we evaluated the incidence and risk factors of sensory impairments among prematurely born children. OBJECTIVES: Our aim was to determine and compare the incidences of sensory impairments among very preterm (VP) (<32 + 0/7 weeks), moderately preterm (MP) (32 + 0/7–33 + 6/7 weeks), late preterm (LP) (34 + 0/7–36 + 6/7 weeks), and term infants (≥37 weeks) and to establish risk factors of neurosensory disabilities. METHODS: This national register study included all live-born infants in Finland between 1991 and 2008. Infants who died before the age of 1 year, who had any major congenital anomaly, or had missing data were excluded (n = 21 007; 2.0%). A total of 1 018 256 infants were analyzed. Incidences of hearing loss, visual disturbances or blindness, other ophthalmologic disorders, and retinopathy of prematurity were determined for gestational age (GA) groups. Risk factors of hearing loss and visual disturbances or blindness were analyzed. RESULTS: The incidences of sensory impairments decreased with advancing GA at birth (P < .001). The most prominent factors associated with increased risks of hearing loss and visual impairment were intracranial hemorrhage and convulsions. VP (odds ratio [OR] 2.34; 95% confidence interval [CI] 1.75–3.14) and LP (OR 1.26; 95% CI 1.04–1.52) births were associated with an increased risk of hearing loss, and VP (OR 1.94; 95% CI 1.55–2.44), MP (OR 1.42; 95% CI 1.11–1.80), and LP (OR 1.31; 95% CI 1.16–1.49) births predicted an increased risk of visual impairment. CONCLUSIONS: Incidences of sensory impairment decreased with increasing GA at birth. The most prominent risk factors predictive of sensory disabilities were intracranial hemorrhage and convulsions. VP and LP births were associated with an increased risk of hearing loss, and VP, MP, and LP births were associated with an increased risk of visual impairment.

Response to Dr. Kawada

We thank Dr. Kawada for his interest in our paper and taking time to raise some valuable comments. In our study, we analyzed a large amount of population-based register data with national coverage and a substantial number of infants. The available data allowed adjustments for multiple maternal-, delivery-, and newborn-related background factors. We are aware of the weaknesses of our study, such as lack of data on parental asthma or duration of breastfeeding. As Dr. Kawada mentioned, there are also some other important environmental and nutritional factors after birth, and factors like prenatal maternal stress, which should be considered as risk factors for asthma and atopic dermatitis in childhood. Unfortunately, such data were not available in our study. We agree that further studies are needed to evaluate predictors for asthma and atopic dermatitis in children.