Biomedical subjects
T Markestad
Publications and source records attributed to T Markestad.
[Time for registries in perinatology].
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Neuropsychological performance in low birth weight preschoolers: a population-based, controlled study.
UNLABELLED: The aim was to evaluate neuropsychological performance and its pre-, and perinatal predictors in low birth weight (LBW) preschool children. A population-based sample of 137 5-year-old children with birth weights less than 2000 g and without major handicaps was compared with a random sample of 152 normal birth weight term controls. Main assessment tools were all subscales from the Wechsler Preschool and Primary Scale of Intelligence Revised, subscales from the Illinois Test of Psycholinguistic Abilities and tests of manual dexterity and figure copying. The LBW children showed significantly lower mean scores compared to controls on tests of visuo-spatial and visuo-motor abilities, but were comparable to controls in other areas, confounding parental factors were controlled for. 14 of the LBW children, there were signs of maternal chorio-amnionitis. Twelve of these had premature rupture of membranes lasting more than 24 h. These 14 children had a mean performance IQ of 87 (SD 5) compared to 100 (SD 15) for the LBW children without maternal signs of chorio-amnionitis (P = 0.001). Having a small head circumference at birth was a less powerful, but statistically significant predictor of impaired performance. CONCLUSION: Low birth weight is associated with impaired performance on visuo-spatial and visuo-motor tasks. Signs of maternal chorio-amnionitis and a small head circumference at birth may be risk factors for such impairment.
Abandoning prone sleeping: Effect on the risk of sudden infant death syndrome.
OBJECTIVE: This study was designed to evaluate the long-term effect of a campaign to avoid prone sleeping on the sudden infant death syndrome (SIDS) mortality rate and on parents' choice of sleeping position for young infants. Before the campaign, 64% of infants usually slept prone and the SIDS rate was 3.5 (95% CI, 2.64 to 4.36) per 1000 live births. STUDY DESIGN: Population-based case reference study of infants dying suddenly and unexpectedly at the ages of 1 week to 1 year, and of 493 healthy infants between 2 and 6 months of age, starting 4 years after an intervention program to avoid prone sleeping. RESULTS: The SIDS rate was 0.3 per 1000 live births (95% CI, 0.05 to 0.54). One of five (20%) SIDS victims usually slept prone, three of five (60%) were placed prone for their last sleep, and five of six were found dead in the prone position. Of the reference infants, 1.4% were usually placed prone to sleep, although all had previously accepted a non-prone position. Nearly half of the infants (49.1%) were usually placed supine, 22.7% usually on the side, and 26.8% in variable positions of which 2.0% occasionally included prone. The side position was the least stable position. After the age of 1 week, 59.4% of infants had been found with their heads covered on at least one occasion. CONCLUSIONS: SIDS is rare when prone sleeping is avoided. Infants at the age of particular risk for SIDS may spontaneously turn from the side to the prone position, and they commonly slip under the bedding during sleep.
Sociodemographic risk factors for sudden infant death syndrome: associations with other risk factors. The Nordic Epidemiological SIDS Study.
The aim of this study was to investigate associations between sudden infant death syndrome (SIDS) and social factors in the Nordic countries. A case-control study was conducted in Denmark, Norway and Sweden: The Nordic Epidemiological SIDS Study. Parents of 244 SIDS infants and 869 control infants matched on gender, age at death and place of birth filled in questionnaires. The dataset was analysed by conditional logistic regression. In univariate analysis, the following sociodemographic factors were associated with an increased risk of SIDS: low maternal age [odds ratio (OR) 7.8; 2.8-21.5], high birth order (OR 4.4; 2.5-7.5), single motherhood (OR 2.9; 1.7-5.0), low maternal education (OR 4.5; 2.8-7.1), low paternal education (OR 3.0; 1.9-4.7), maternal unemployment (OR 2.4; 1.8-3.4) and paternal unemployment (OR 4.0; 2.7-5.9). In a multivariate analysis where maternal smoking was also included, only paternal unemployment, young maternal age and high birth order remained significantly associated with SIDS. Housing conditions were not associated with SIDS. However, the risk of SIDS was high if the family had lived in their present home for only a few years (OR 2.3; 1.3-4.1). Sociodemographic differences remain a major concern in SIDS in a low-incidence situation and even in an affluent population with adequate health services.
A case-control study of smoking and sudden infant death syndrome in the Scandinavian countries, 1992 to 1995. The Nordic Epidemiological SIDS Study.
AIM: To establish whether smoking is an independent risk factor for sudden infant death syndrome (SIDS), if the effect is mainly due to prenatal or postnatal smoking, and the effect of smoking cessation. METHODS: The analyses were based on data from the Nordic epidemiological SIDS study, a case-control study with 244 cases and 869 controls. Odds ratios were computed by conditional logistic regression analysis. RESULTS: Smoking emerged as an independent risk factor for SIDS, and the effect was mainly mediated through maternal smoking in pregnancy (crude odds ratio 4.0 (95% confidence interval 2.9 to 5.6)). Maternal smoking showed a marked dose-response relation. There was no effect of paternal smoking if the mother did not smoke. Stopping or even reducing smoking was beneficial. SIDS cases exposed to tobacco smoke were breast fed for a shorter time than non-exposed cases, and feeding difficulties were also more common. CONCLUSIONS: Smoking is an independent risk factor for SIDS and is mainly mediated through maternal smoking during pregnancy. Stopping smoking or smoking less may be beneficial in reducing the risk of SIDS.
[Congenital hip dislocation. Ultrasonic screening of newborn infants].
Despite the introduction of clinical screening and early treatment of congenital dislocation of the hip (CDH), the prevalence of subluxated/luxated hips in later infancy is still reported to be as high as 1-3 per 1,000 infants. Using ultrasound, it is possible to evaluate both hip morphology and hip stability. Hip morphology is best evaluated using Graf's coronal section through the deepest part of the acetabulum. Classification of the hips into different categories can then be based on measuring the angle of inclination of the acetabulum (alpha-angle) or femoral had coverage. Hip stability can be assessed by a Barlow-equivalent provocation test during the ultrasound examination. In the Norwegian newborn population approximately 85% of the infants have morphologically normal hips (based on the alpha-angle) while 12% have immature and 3% dysplastic hips. About 80-90% of infants with dysplastic acetabula show only minor changes, and many of the hips may normalize without treatment. Several studies indicate that universal ultrasound screening might reduce the occurrence of late diagnosed congenital dislocation of the hip.
Evaluation of a protocol for selecting fetuses in breech presentation for vaginal delivery or cesarean section.
OBJECTIVE: Our purpose was to evaluate, with respect to obstetric intervention and neonatal outcome, a protocol for selecting fetuses in breech presentation for vaginal delivery or cesarean section. STUDY DESIGN: A clinical follow-up study was performed between 1984 and 1992 of all term singleton deliveries in breech presentation. Each case selected for vaginal delivery had a matched control in vertex presentation. RESULTS: A total of 1212 infants presented as breech. Vaginal delivery increased from 45% to 57% (p = 0.004), and cesarean section for failure of vaginal delivery declined from 21% to 6% (p < 0.00001). None, however, died or had long-term sequelae because of a complicated or failed vaginal breech delivery. A total of 8.8% of those delivered vaginally in breech versus 5.0% of those in vertex presentation were admitted to the neonatal intensive care unit (p = 0.009). Among those with vaginal delivery, 2.5% in breech presentation were given the clinical diagnosis of birth asphyxia versus none in the vertex position (p = 0.0001). CONCLUSION: Breech presentation at term may be selected for vaginal delivery if properly managed.
Dubowitz assessment of gestational age and agreement with prenatal methods.
We compared assessment of gestational age by Dubowitz score with ultrasonic measurement of the biparietal diameter (BPD), and then evaluated how infants were classified by these methods as small-for-gestational age (SGA), and as pre- or post-term births. BPD gestational age was assessed at week 17 to 20 of pregnancy while the Dubowitz scoring was done at birth. "Limits of agreement" between methods and kappa values were calculated and used to evaluate agreement. Among 839 included infants, there was moderate agreement between Dubowitz score and BPD (limits of agreement; -2.3; +2.1 weeks; weighted kappa: 0.46) in the assessment of gestational age. Agreement between Dubowitz score and BPD in the classification of SGA (kappa: 0.75, 95% confidence interval [CI]: 0.69-0.81) and preterm infants (kappa: 0.68, 95% CI: 0.56-0.80) was good, whereas agreement on infants born post-term was no better than chance (kappa: 0.14, 95% CI: -0.02(-)+0.30). We conclude that despite moderate agreement between Dubowitz score and BPD in the assessment of gestational age, agreement in the classification of low-birth-weight infants as SGA and as premature births was good.
Incidence of retinopathy of prematurity (ROP) in the western part of Norway. A population-based retrospective study.
We have investigated the incidence of retinopathy of prematurity (ROP) among premature infants with birth weight less than 1500 g in two Norwegian counties during the years 1989-1993. Two hundred and seven out of 244 such infants (84.8%) were examined at the neonatal intensive care unit; 66 of those examined (31.9%) had a birth weight below 1000 g. ROP was found in 21 patients (10.1%), and stage 3 disease was present in 7 (3.4%). No patient had more advanced ROP than stage 3. Assuming that no cases of stage 3 ROP were missed among the total of 244 children, the incidence of stage 3 disease was 2.9%. The frequency of ROP in this study is compared to that of other population-based studies in the Nordic countries, and incidence differences are discussed.
The decline in the incidence of SIDS in Scandinavia and its relation to risk-intervention campaigns. Nordic Epidemiological SIDS Study.
A prospective case-control study of sudden infant death syndrome (SIDS) in Norway, Denmark and Sweden between September 1, 1992 and August 31, 1995 comprised 244 cases and 869 matched controls. After the introduction of risk-intervention campaigns, the SIDS incidence decreased from 2.3/1000 live births in Norway, 1.6 in Denmark and 1.0 in Sweden to 0.6/1000 or fewer in all the Scandinavian countries in 1995. The decrease paralleled a decline in the prone sleeping position and there was an accompanying parallel fall in total postneonatal mortality in all three countries. Thus, the risk-reducing campaigns for SIDS have been successful not only in Norway and Denmark, starting from relatively high incidences, but also in Sweden, starting from a low incidence. During the study period, a gradual increase was observed for the effects of prone sleeping, smoking and bottle-feeding as risk factors for SIDS.
Behaviour and physiological responses during prone and supine sleep in early infancy.
AIMS: To study the effect of prone and supine sleep on infant behaviour, peripheral skin temperature, and cardiorespiratory parameters to aid understanding of why prone sleeping is associated with an increased risk of sudden infant death syndrome. METHODS: Of 33 enrolled infants, 32 were studied at 2.5 and 28 at 5 months of age. A computer aided multichannel system was used for polysomnographic recordings. Behaviour was charted separately. RESULTS: Prone REM (active) sleep was associated with lower frequencies of short arousals, body movements and sighs, and a shorter duration of apnoeas than supine REM sleep at both ages. At 2.5 months there were less frequent episodes of periodic breathing during prone sleep in non-REM (quiet) and REM sleep. Heart rate and peripheral skin temperature were higher in the prone position during both sleep states at both ages. CONCLUSIONS: The observation of decreased variation in behaviour and respiratory pattern, increased heart rate, and increased peripheral skin temperature during prone compared with supine sleep may indicate that young infants are less able to maintain adequate respiratory and metabolic homoeostasis during prone sleep.
Use of sucrose as a treatment for infant colic.
AIMS: To examine if sucrose has an analgesic effect on infant colic. METHODS: Nineteen infants with typical infant colic were given 2 ml of 12% sucrose or distilled water when crying, in a double blind double crossover study. The effect was measured by parents' score. RESULTS: Twelve improved specifically on sucrose and one on placebo (p < 0.01). Five showed a non-specific improvement. CONCLUSIONS: Sucrose has a significant ameliorating effect on infant colic.
Consequences of getting the head covered during sleep in infancy.
OBJECTIVE: To study the consequences of getting the head covered by bedding (fiber quilt) on carbon dioxide (CO2) accumulation around the face, behavior, and physiologic responses during prone and supine sleep in infants to add understanding to why victims of sudden infant death syndrome are often found under the bedding. METHPDOLOGY: Of 33 healthy term, usually nonprone sleeping infants, behavior and computerized polysomnography were successfully recorded for 30 during prone and supine sleep at 21/2 months and for 23 prone and 25 supine at 5 months. RESULTS: For both ages and body positions, covering the head resulted in significant CO2 accumulation around the face, fewer apneas (3 to 10 seconds), shorter duration of apneas after sighs, higher heart and respiratory rates, and peripheral skin temperature. Differences were generally greater at 21/2 than at 5 months. While covered, the prone position was associated with higher CO2 levels close to the face, slightly higher transcutaneous PCO2, and higher heart rates and peripheral skin temperatures than the supine position. In the supine position 23% were able to remove the cover from the head at 21/2 and 60% at 5 months, whereas only 1 infant of 5 months managed to remove the cover when prone. CONCLUSIONS: The observed responses are consistent with a potential for distress when the head is covered, particularly when placed prone. Probably most important with respect to sudden infant death syndrome is the infants' inability to remove the bedding from the head upon awakening from prone sleep.
Combined effects of sleeping position and prenatal risk factors in sudden infant death syndrome: the Nordic Epidemiological SIDS Study.
OBJECTIVE: Prone sleeping is a strong risk factor for sudden infant death syndrome (SIDS). We investigated whether the combined effect of prone sleeping position and prenatal risk factors further increased the SIDS risk. METHODS: In the Nordic Epidemiological SIDS Study, parents of SIDS victims in Denmark, Norway, and Sweden completed a questionnaire on potential risk factors for SIDS. Forensic pathologists verified the SIDS diagnosis. Four controls of the same gender, age, and place of birth were selected. This matched case-control study, which included 244 SIDS cases and 869 controls from 1992 to 1995, was analyzed by conditional logistic regression. RESULTS: Odds ratios (ORs) for prone and side sleeping compared with supine sleeping for the last sleep were 13.9 (95% confidence interval 8.2-24) and 3.5 (2.1-5.7). Infants 13 to 24 weeks old had particularly high risk in prone and side sleeping, at 28.5 (7.9-107) and 5.9 (1.6-22). OR for prone sleeping was higher in girls, at 30.4 (11-88), than in boys, 10.3 (5.5-19). We found strong combined effects of sleeping position and prenatal risk factors (more than multiplicative). The OR for prone and side sleeping was increased for infants with birth weight <2500 g, at 83 (25-276) and 36.6 (13-107); for preterm infants, at 48.8 (19-128) and 40.5 (14-115); and for intrauterine growth retarded, at 38.8 (14-108) and 9.6 (4.3-22), compared with supine position in infants without these prenatal factors. The combined effect of nonsupine positions and intrauterine growth retarded was highest among 13- to 24-week-old infants. Effects of combined presence of nonsupine sleeping positions and each of the factors of smoking in pregnancy, young maternal age, higher parity, low level of maternal education, and single motherhood were more than additive. Attributable fractions in the population for prone and side sleeping were 18.5% and 26.0%. CONCLUSIONS: Both prone and side sleeping increased the risk of SIDS. The risk was increased further in low birth weight infants, preterm infants, and infants at the age of 13 to 24 weeks, suggesting that SIDS may be triggered by nonsupine sleeping in infants with prenatal risk factors during a vulnerable period of postnatal development.
Prediction of fetal growth based on maternal serum concentrations of human chorionic gonadotropin, human placental lactogen and estriol.
BACKGROUND: The purpose was to determine the usefulness of maternal serum concentrations of human chorionic gonadotropin (hCG), human placental lactogen (hPL) and estriol as predictors of fetal growth. METHOD: From a large cohort serum obtained serially at 17, 25, 33 and 37 weeks of gestation were analyzed for randomly selected pregnancies resulting in small for gestational age (SGA, n = 102) and non-SGA (n = 112) infants. RESULTS: There were no significant correlations between birthweight ratio (ratio of birthweight to mean weight for gestational age) and hCG, but between birthweight ratio on one hand and estriol for all stages of pregnancy (r = 0.19-0.38, p < 0.01 - p < 0.001) and hCL except at 33 weeks (r = 0.11-0.40, p ns-p < 0.001) on the other. There were statistically significant, but small median differences and substantial overlaps between the SGA and non-SGA infants for hCG at 17 and 37 weeks, for hPL at 17, 33 and 37 weeks, and for estriol at all the stages of pregnancy. The sensitivity and positive predictive value of low hormone concentrations (below the 10th percentile) in predicting the birth of an SGA infant were in the range of 6-26% and 17-39%, respectively. The corresponding specificity and prediction of a non-SGA infant from normal levels were 91-93% and 85-88%. CONCLUSIONS: HPL and estriol, but not hCG concentrations, are positively related to the size of the fetus, but the relationships are too weak to be of predictive value in an unselected population.
Cell division in placentas of appropriate and small-for-gestational-age infants. A flow cytometry study.
BACKGROUND: The purpose of this study was to examine if placentas of small- for-gestational-age (SGA) and non-SGA infants differ with respect to proliferative cell activity. METHOD: Cell cycle distribution was studied in placentas from 181 SGA (birthweight < 10th percentile) and 528 non-SGA births by flow cytometry measurements of relative DNA content. RESULTS: The fraction of cells in various cell cycle phases (G1-, S- and G2-phases) did not differ with gestational age from 30 to 43 weeks in either of the groups. The placentas of the SGA infants had a significantly lower mean (+/-1 SEM) growth fraction than placentas of non-SGA infants (S-phase 5.2 +/- 0.2 vs 5.5 +/- 0.1, p = 0.05, and G2-fraction 5.4 +/- 0.2 vs 6.3 +/- 0.1, p < 0.001), but the overlaps of the distributions were large. Thus sensitivity, specificity and predictive values of low fractions did not differ substantially-from a purely random prediction of SGA. CONCLUSIONS: Cell division in the placenta is maintained until and beyond term. Placentas of SGA infants have on average, lower proliferative activity than placentas of non-SGA infants, but the difference is too small to be of predictive value in identifying intrauterine growth retardation.
Body proportions and early neonatal morbidity in small-for-gestational-age infants of successive births.
BACKGROUND: We wanted to examine if infants who were small for gestational age (SGA) at term had increased perinatal mortality or morbidity compared to non-SGA infants, and if this could be related to the infant's body proportions, or to whether the mother previously had delivered a low-birthweight infant ("repeater") or not ("non-repeater"). METHODS: From a cohort of 5722 para 1 and para 2 women, we compared perinatal mortality in 541 SGA (birthweight < 10th percentile) and 4737 non-SGA infants. From the same cohort, early neonatal morbidity was studied in 368 SGA and 462 control infants without congenital malformations. RESULTS: SGA infants had a 6.4 (95% CI: 2.6-15.7) higher risk of perinatal death than controls, but when infants who died with congenital malformations were excluded, this risk was not significantly increased. SGA infants were more often transferred to an intensive care unit than controls (1.7, 95% CI: 1.0-2.9). Among SGA births, infants with asymmetric body proportions (i.e. low ponderal index) more often had symptoms in the neonatal period (RR: 2.5; 95% CI: 1.4-4.3) and were more often transferred to an intensive care unit (3.4; 95% CI: 1.6-7.4) than symmetric SGA infants, whereas there were no differences between SGA infants of repeaters and non-repeaters. CONCLUSIONS: We found that SGA infants had higher perinatal mortality than controls, but this was due to a higher prevalence of congenital malformations. Among SGA infants without malformations, our results indicated increased neonatal morbidity in infants with asymmetric body proportions.