Keijzer-Veen, M.G.

Reduced renal length and volume 20 years after very preterm birth (Article)

2010-03-01T00:00:00Z

Intrauterine growth retardation is presumed to be associated with decreased renal size and impaired renal function as a result of stunted kidney development and nephron deficit. To study whether very preterm birth also affects renal size at young adulthood, we sonographically measured bipolar kidney length and volume in 51 very premature individuals (<32 weeks of gestation), either small (SGA) or appropriate (AGA) for gestational age (22 SGA and 29 AGA), and 30 full-term controls 20 years after birth. Relative kidney length and volume were calculated. Both absolute and relative left kidney length and volume were significantly lower in SGA and AGA individuals, otably in women. Renal size did not differ between SGA and AGA individuals. In 70% of controls, the left kidney was larger than the right one compared with 40.9% in SGA [relative risk (RR) 1.7; 95% confidence interval (CI) 1.0 -3.0] and 48.3% in AGA (RR 1.5; 95% CI 0.9-2.3) individuals. Renal structural anomalies were present in eight prematurely born participants only. Our data suggest that kidney growth is stunted after preterm birth, especially on the left side, and in the female gender.

Very preterm birth is a risk factor for increased systolic blood pressure at a young adult age (Article)

2010-03-01T00:00:00Z

Children born very prematurely who show intrauterine growth retardation (IUGR) are suggested to be at risk of developing high blood pressure as adults. Renal function may already be impaired by young adult age. To study whether very preterm birth affects blood pressure in young adults, we measured 24-h ambulatory blood pressure (SpacelabsTM90207 device) and renin concentration in 50 very premature individuals (<32 weeks of gestation), either small (SGA) or appropriate (AGA) for gestational age (21 SGA, 29 AGA), and 30 full-term controls who all were aged 20 years at time of measurement. The mean (standard deviation) daytime systolic blood pressure in SGA and AGA prematurely born individuals, respectively, was 122.7 (8.7) and 123.1 (8.5) mmHg. These values were, respectively, 3.6 mmHg [95% confidence interval (CI) -0.9 to 8.0] and 4.2 mmHg (95% CI 0.4-8.0) higher than in controls [119.6 (7.6)]. Daytime diastolic blood pressure and nighttime blood pressure did not differ between groups. We conclude that individuals born very preterm have higher daytime systolic blood pressure and higher risk of hypertension at a young adult age.

Antenatal glucocorticoid treatment is not associated with long-term metabolic risks in individuals born before 32 weeks of gestation (Article)

2008-11-01T00:00:00Z

Background: A single course of maternal glucocorticoid treatment is effective in reducing neonatal mortality after preterm birth. However, in animals, maternal glucocorticoid treatment is associated with lifelong hyperglycemia and hypertension, and impaired nephrogenesis in offspring. Findings from studies in humans on this topic are highly contradictory due to a number of methodological flaws, and renal function after glucocorticoid exposure has never been assessed. Objectives: To assess in individuals born <32 gestational weeks whether antenatal glucocorticoid treatment for preterm birth is associated with long-term metabolical risks, including renal function, in adulthood. Design: Birth cohort study. Setting: Multicentre study. Patients: 412 19 year olds born <32 gestational weeks from the Project On Preterm and Small-for-gestational-age infants (POPS) cohort. Interventions: Maternal betamethasone 12 mg administered twice with a 24 h interval. Main outcome measures: Body composition, insulin resistance, the serum lipid profile, blood pressure and estimated renal function. Results: We did not find any long-term adverse effects of antenatal betamethasone, with the exception of an effect on glomerular filtration rate (GFR). In 19-year-old survivors, GFR was lower after betamethasone: -5.2 ml/min (95% CI -8.9 to -1.4) per 1.73 m2. Conclusions: The reduction in neonatal mortality associated with a single course of maternal betamethasone is not accompanied by long-term metabolical risks in survivors of preterm birth. The only adverse effect found was lower GFR. Although this difference was not clinically relevant at 19 years, it might predict an increased risk of chronic renal failure in prematurely born individuals who were exposed antenatally to betamethasone.

Renal Function and Size at Young Adult Age After Intrauterine Growth Restriction and Very Premature Birth (Article)

2007-10-01T00:00:00Z

Background: Premature birth and intrauterine growth restriction may increase the risk of developing renal disease at adult age. Renal function may already be impaired at young adult age. Study Design: Cross-sectional study. Setting & Participants: Very premature individuals (gestational age < 32 weeks) recruited from Project on Premature and Small for Gestational Age Infants and full-term-born controls (37 to 42 weeks) recruited from a children's hospital in Rotterdam, The Netherlands. All individuals were 20 years of age at the time of study. Predictors: Gestational age and birth weight: premature and small for gestational age (SGA; n = 23), premature and appropriate for gestational age (n = 29), and controls (n = 30). Outcomes & Measurements: Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and filtration fraction before and after renal stimulation with low-dose dopamine infusion and oral amino-acid intake. Urine albumin and renal ultrasound. Results: Height, weight, kidney length and volume, GFR, and ERPF were significantly lower in the SGA group than in controls. After adjustment for body surface area, GFR did not differ significantly among groups. Mean ERPF was 71 mL/min/1.73 m2(95% confidence interval [CI], 3 to 139) less, but filtration fraction was only 1.3% (95% CI, -0.3 to 3.0) greater, in the SGA group than controls. Renal stimulation significantly increased GFR and ERPF and decreased filtration fraction in all groups. After renal stimulation, ERPF was 130 mL/min/1.73 m2(95% CI, 21 to 238) greater in the SGA group than controls, but GFR and filtration fraction did not differ significantly among groups. Microalbuminuria was present in 2 patients (8.7%) in the SGA group, but none in the appropriate-for-gestational-age group or controls. Renal function correlated with renal size. Limitations: Small sample size. Conclusions: Our findings do not fully support the hypothesis that preterm birth in combination with intrauterine growth restriction contributes to renal function alterations at young adult age. Larger studies are needed to evaluate this hypothesis.

Response to Tu and Gilthorpe: Preventing misinterpretation of coefficients in analysis of fetal origins of adult disease (Article)

2007-03-01T00:00:00Z

Early Determinants of Blood Pressure and Renal Function: Follow-up of very preterm born individuals until young adulcy (Doctoral Thesis)

2006-04-12T00:00:00Z

In summary, the studies described in this thesis suggest that premature birth affects renal function and blood pressure at (young) adult age, and especially when born both SGA and premature. Minor differences are already detectable at young adult age. The biological mechanism is likely to originate from a decreased renal development, with alterations of vascular structure and limited nephron number.

Microalbuminuria and lower glomerular filtration rate at young adult age in subjects born very premature and after intrauterine growth retardation. (Article)

2005-12-01T00:00:00Z

This prospective follow-up study of 422 19-yr-old subjects born very preterm in The Netherlands was performed to determine whether intrauterine growth retardation (IUGR) predisposes to abnormal GFR and microalbuminuria in adolescents. GFR (ml/min per 1.73 m2) was estimated using the Cockcroft-Gault equation, and albumin-creatinine ratio (mg/mmol) was calculated in a cohort of 19-yr-old subjects born very preterm (gestational age <32 wk) in 1983. Birth weights were adjusted for gestational age and expressed as standard deviation scores (sds) as a measure of IUGR. All subjects had normal renal function. Birth weight (sds) was associated negatively with serum creatinine concentration (micromol/L) (beta = -1.0 micromol/L, 95% confidence interval [CI]: -1.9 to -0.2), positively with GFR (beta = 3.0, 95% CI: 1.7 to 4.2), and negatively with the logarithm of albumin-creatinine ratio (beta = -0.05, 95% CI: -0.09 to -0.01) in young adults born very preterm. IUGR is associated with unfavorable renal functions at young adult age in subjects born very premature. These data suggest that intrauterine growth-retarded subjects born very premature have an increased risk to develop progressive renal failure in later life.

Is blood pressure increased 19 years after intrauterine growth restriction and preterm birth? A prospective follow-up study in The Netherlands. (Article)

2005-09-01T00:00:00Z

OBJECTIVE: To determine whether intrauterine growth restriction (IUGR) is a predisposing factor for high blood pressure (BP) in 19-year-olds who were born (very) preterm. METHODS: A prospective follow-up study was conducted at age 19 in individuals who born preterm in the Netherlands in 1983. Systolic, diastolic, and mean BP values and plasma renin activity concentration were obtained in 422 young adults who were born with a gestational age (GA) <32 weeks. BP values were also measured in 174 individuals who born with a GA of > or =32 weeks and a birth weight of <1500 g. RESULTS: An increased prevalence of hypertension and probably also of prehypertensive stage was found. IUGR, birth weight, GA, and plasma renin activity were not associated with BP. Current weight and BMI were the best predicting factors for systolic BP at the age of 19 years. CONCLUSIONS: The prevalence of hypertension is high in individuals who were born preterm when compared with the general population. In the individuals who were born very preterm, no support to the hypothesis that low birth weight is associated with increased BP at young adult age can be given.