Biomedical subjects

V Y Yu

Publications and source records attributed to V Y Yu.

At least 73 records · Page 4Linked to original sources

PubMed1986

Prognosis for infants born at 23 to 28 weeks' gestation.

The survival and neurodevelopmental outcome of 356 extremely preterm infants born at 23 to 28 weeks' gestation were reported by week of gestation. Their corrected 1 year survival improved from 7% at 23 weeks to 75% at 28 weeks. The overall incidence of impairment was 19% and of major disability 12%. Boys had a significantly lower normal survival than girls. Multiple births had a significantly lower survival and higher incidence of impairment than singleton births. Predictions of outcome were made before delivery, after resuscitation, and at 1 week to aid the development of guidelines on when perinatal intensive care is justified, whether obstetric intervention for fetal reasons is warranted, and what initial and ongoing prognoses to give to parents. Intensive care for progressively smaller and more immature infants, many of whom were previously considered non-viable, needs to be carefully monitored by every perinatal centre.

Developmental Disabilities↗

PubMed1986

Neurodevelopmental outcome of periventricular haemorrhage and leukomalacia in infants 1250 g or less at birth.

The brains of 50 consecutively admitted infants weighing 1250 g or less at birth were serially examined beyond the neonatal period for periventricular haemorrhage and for periventricular leukomalacia with real-time ultrasound. There was significant correlation between the presence or absence and the severity of haemorrhage with survival. A prospective neurodevelopmental assessment was completed at 2 years of age, corrected for prematurity, on all survivors. None of the 20 survivors with normal scans or germinal layer haemorrhages had evidence of major disability and all four survivors with intracerebral haemorrhage or periventricular leukomalacia had major disability. The mental performance on the Bayley scales of infant development was also significantly worse in the latter group. Six of the eight survivors with intraventricular haemorrhage had no major disability, including three who had post-haemorrhagic hydrocephalus. Our results showed that cerebral ultrasound detection of brain pathology is a good predictor of neurodevelopmental outcome in such extremely low birthweight infants. However, as the maximum extent of periventricular haemorrhage may develop beyond one week of age and cystic periventricular leukomalacia commonly develops after the neonatal period, serial scanning is mandatory to ensure diagnostic accuracy for both periventricular haemorrhage and leukomalacia.

Blindness↗

PubMed1986

Pulmonary interstitial emphysema in infants less than 1000 g at birth.

Eighty (32%) of 249 infants weighing less than 1000 g at birth developed pulmonary interstitial emphysema (PIE); its incidence was 42% in infants at 500-799 g, 29% at 800-899 g and 20% at 900-999 g. Fifty-five per cent occurred in the first 24 h and 43% were associated with other forms of air leak. The incidence and mortality of PIE did not improve between 1977 and 1984. The mortality rates in infants with or without PIE were not significantly different in the first 4 years of the study period (53% vs 45%). As the mortality improved in infants without PIE during the second 4 years, the difference in mortality rates in infants with or without PIE became significant (68% vs 29%). PIE continues to be associated with serious mortality and morbidity in extremely low birthweight infants. Effective measures to prevent PIE are required before further improvement in their outcome can be achieved.

Female↗

PubMed1986

Periventricular haemorrhage and leukomalacia in extremely low birthweight infants.

Forty (49%) of 82 extremely low birthweight (ELBW, less than 1000 g) infants had periventricular haemorrhage (PVH). Ten (12%) had germinal layer haemorrhage (GLH) alone, 16 (20%) had intraventricular haemorrhage (IVH) and 14 (17%) had intracerebral haemorrhage (ICH). Almost all the cases of PVH had developed by 4 days of age. Small-for-gestational age infants (12% of study population) had a significantly lower incidence and severity of PVH than appropriate-for-gestational age infants. Of 94 infants born between 23 and 28 weeks gestation, 45 (48%) had PVH. The PVH incidence was 60% in those of 23-26 weeks and 38% in those of 27-28 weeks. The hospital survival rate of ELBW infants was 69% in those without PVH and 43% in those with PVH; 70% in GLH alone; 50% in IVH and 14% in ICH. Three survivors developed post-haemorrhage hydrocephalus of whom two required ventriculoperitoneal shunting. Five survivors developed periventricular leukomalacia (PVL) evidenced by cysts identified between 3 and 7 weeks of age. A significant decrease in the incidence of PVH occurred over the study period (67% in 1982, 38% in 1983 and 33% in 1984). This decrease was seen for all grades of PVH. The reasons for this decreased incidence are still to be ascertained but this trend suggests that improvements in neonatal intensive care have the potential to improve the neurological outcome of more recent ELBW survivors.

Cerebral Hemorrhage↗

PubMed1986

Sequelae of growth failure in appropriate for gestational age, very low-birthweight infants.

The pattern of growth of 235 very low-birthweight children, whose weights were appropriate for gestational age, was characterised by a significant decline in weight, length and head circumference from birth to discharge from hospital, followed by partial recovery in all three measures of growth by two years corrected age. 29 per cent of the children were below the 10th percentile for weight at two years, and this group had a significantly higher incidence of major disabilities, poorer muscular development, more hypotonia and lowered performance on the psychomotor index of the Bayley Scales of Infant Development than their heavier peers. These children's mothers more often perceived them as actively disliking close physical contact, and they were reported by their mothers to have had more infections, minor surgery and chronic otitis media. Taken together, the suboptimal weight-gain, delayed gross motor development and increased maternal perceptions of 'sickliness' and lack of 'cuddliness' in these children are reminiscent of non-organic failure to thrive.

Body Height↗

PubMed1986

Outcome of extremely-low-birthweight infants.

The overall 1-year survival rate of 261 infants born at 500 g-999g over a 7-year period was 46%. The survival rate of the 220 inborn infants, corrected for birth defects, would have increased from 47% to 57% if delivery room deaths were excluded and to 62% if postneonatal deaths had also been ignored. Survival improved progressively with increasing 100g weight groups. The disability rate in the 108 survivors who were at least 2 years old corrected for prematurity was 28% with little variation between the 100g weight groups. There were no significant trends in annual perinatal mortality, 1-year survival and disability rate in survivors over the study period for the inborn population. The male infants had significantly lower normal-survival rate than the female infants. Small-for-gestational-age infants, comprising 11% of the inborn group, had significantly better survival but a higher disability rate. Multiple births had significantly lower survival and normal-survival rates than had singleton births. Infants whose mothers were transferred for delivery at the perinatal centre before onset of labour had a significantly better survival rate than those whose mothers had 'booked' and those who were transferred in labour.

Body Weight↗

PubMed1986

Subsequent pregnancy following the birth of an extremely low birth-weight infant.

Of 103 mothers who delivered an extremely low birth-weight (ELBW, less than 1,000g) infant, 29% were primiparous; 51% of those who were multiparous had at least one previous miscarriage or perinatal death. The 41 (40%) mothers who decided against subsequent pregnancy were significantly older than the remaining mothers. Mothers were also significantly more likely to decide against subsequent pregnancy if their ELBW infant had survived. The outcome of subsequent pregnancies within 3 years of the ELBW birth was ascertained; 28% ended in miscarriage, 3% in stillbirth, 1% in neonatal death, 21% in a surviving preterm infant and 51% in a survivor born at term. Mothers diagnosed to have cervical incompetence had a significantly higher risk of a subsequent preterm birth. During the study period, 87% of mothers who became pregnant subsequent to their ELBW infant gave birth to at least one surviving child. Of the subsequent livebirths, 36% were less than 2,500g, 11% were less than 1,500g and 5% were less than 1,000g. Significantly more mothers whose ELBW infant had died conceived again within 1 year compared to those whose ELBW infant had survived. The necessary time for recovery from bereavement may be cut short by the subsequent pregnancy. The psychological problems as a result of unresolved mourning which mothers experience and their effects on subsequent children need to be further studied.

Abortion, Spontaneous↗

PubMed1986

Pulmonary air leak in extremely low birthweight infants.

The incidence of pulmonary air leak in 230 infants with a birth weight of 500-999 g who were ventilated was 41%. Pulmonary interstitial emphysema occurred in 35%, pneumothorax in 20%, pneumomediastinum in 3%, and pneumopericardium in 2%. The survival rates in those with or without pulmonary air leak were not significantly different in the first four years of the study period (46% v 53%). As the survival improved in infants without air leak during the second four years the difference in survival rates in infants with or without air leak became significant (30% v 71%). Effective measures of preventing pulmonary air leak are required before further improvement in the outcome of these extremely low birthweight infants can be achieved.

Air↗

PubMed1986

The surviving monozygotic twin.

It has been suggested that because of vascular interchange between the monozygous twins vascular disruptions from a deceased cotwin with disseminated intravascular coagulation causes embolisation in the surviving twin. This study reports six cases in which all the surviving monozygous twins had central nervous system infarcts and three had multiple organ infarcts, including pulmonary and hepatic infarcts, which have not been reported previously. Fetal death in utero occurred 1-11 weeks before the live birth of the monozygous survivor. In three cases there was pathological confirmation of a continuing process with infarcts ranging in age from a few days to eight weeks. Four infants died in the early neonatal period, and the remaining two survived with considerable handicap. A review of the published reports confirmed the high risk of vascular disruption affecting many organ systems and the extremely poor prognosis for subsequent death or handicap. We recommend that after detection of fetal death in utero in a suspected monozygous twin pregnancy careful consideration should be given to prompt delivery of the survivor and investigations should be carried out to rule out infarction in the central nervous system and other organs that are at risk.

Adult↗

PubMed1986

Contrast echocardiographic assessment of the neonatal ductus arteriosus.

Contrast echocardiography is a safe and accurate method of diagnosing patent ductus arteriosus (PDA) in newborn infants. In this study the presence of PDA in very low birthweight infants receiving mechanical ventilation was investigated by contrast echocardiography. This was used as a basis for determining the accuracy of clinical signs and M mode echocardiography in the diagnosis of PDA. At the first contrast echocardiographic examination at a mean age of 49 hours PDA was found in 75% of infants. Clinical signs were inconsistent; 42% of the infants with PDA at the first examination had a murmur, no relation being found between PDA and heart rate or cardiothoracic ratio. Left atrial and left ventricular dimensions were significantly raised and left systolic time intervals significantly lower in the group with PDA. There was, however, considerable overlap, with the sensitivity of each measurement varying between 52% and 71%. Left systolic time interval combined with left ventricular:aortic root ratio gives the best differentiation between infants with or without PDA.

Ductus Arteriosus, Patent↗

PubMed1986

Postnatal growth in infants born before 30 weeks' gestation.

The postnatal weight pattern up to 14 weeks after birth was determined in 184 singleton survivors born at 23 to 29 weeks' gestation in whom routine parenteral nutrition was used before milk feeding was established. A mean postnatal weight loss of 14% of birth weight occurred at a mean of 6 days. The more immature infants had significantly higher postnatal weight loss and longer time to regain birth weight despite a higher volume intake in the first week. From the fourth postnatal week all gestational subgroups had a mean weight gain at above intrauterine growth rate. As a result of the initial period of weight loss, however, the mean body weight remained below the 10th percentile of the intrauterine growth curve. The early growth rate in infants small for gestational age was higher than those who were appropriate weight for gestation, although the mean body weight of the former group remained significantly lower at 2 years.

Aging↗

PubMed1986

Perinatal factors and adverse outcome in extremely low birthweight infants.

Perinatal factors associated with death or disability at 2 years were identified in an inborn cohort of 196 live births with a birth weight of 500-999 g. Antepartum haemorrhage, multiple pregnancy, breech presentation, perinatal asphyxia, hypothermia on admission, hyaline membrane disease, persistent pulmonary hypertension, severe respiratory failure, and intraventricular haemorrhage were associated with increased mortality. Factors associated with increased survival included maternal hypertension, caesarean birth, increasing maturity or size at birth, female sex, and fetal growth retardation. Stepwise multiple discriminant function analysis showed that six factors correctly classified the outcome in 83% of infants: intraventricular haemorrhage was the most important factor followed by the presence of acidosis and hypoxia in the early neonatal period, birth weight, pre-eclamptic toxaemia, and caesarean birth. This study also showed that intraventricular haemorrhage, seizures, antepartum haemorrhage and delay in regaining birth weight were associated with increased disability among survivors.

Cerebral Hemorrhage↗

PubMed1986

Reduction in periventricular haemorrhage in preterm infants.

Our previous cerebral ultrasound study of antecedents of periventricular haemorrhage in infants weighing 1250 g or less at birth suggested that neonatal events that caused increased or fluctuating cerebral blood flow lead to periventricular haemorrhage. As the risk period for this type of haemorrhage was the first four days of life strict guidelines were introduced to avoid the previously identified neonatal risk factors. No attempt was made to modify obstetric practice. Over the next two years, although the obstetric risk profile, the frequency and severity of hyaline membrane disease, and the gestation, birth weight, and sex distributions of a similar cohort of infants did not change, the incidence of periventricular haemorrhage decreased significantly from 60% to 36%. Significant antecedents of haemorrhage similar to those found in the previous study included severe bruising, low arterial:fractional inspiratory oxygen ratio and low packed cell volume on admission, hyaline membrane disease, hypercarbia, and hypoxaemia. Assisted ventilation, pneumothorax, treatment with tubocurarine, and hypotension were no longer significant risk factors for periventricular haemorrhage. A multivariate discriminant analysis correctly predicted haemorrhage in 86% of the study group when bruising, hypercarbia, hypoxaemia, hyaline membrane disease, and low gestation were considered. These results suggest that changes in neonatal practices can reduce the incidence of periventricular haemorrhage and that drug studies indicating similar reduction in haemorrhage need to be evaluated carefully to ensure that placebo and treated groups are in fact comparable.

Birth Injuries↗

PubMed1986