Effect of birthplace on infants with low birth weight.

From December 1983 to June 1985, 162 infants of less than 32 weeks'' gestation or weighing less than 1,500 g, or both, were cared for at the regional neonatal intensive care unit in Leeds. Of the 162, 64 (40%) were born in the unit because their mothers had received antenatal care there, 58 (36%) were born in another hospital and subsequently transferred, and 40 (25%) were transferred in utero because of potential complications. The overall mortalities for each group were 14%, 38%, and 18% respectively. These differences were significant, but when they were corrected for gestation, birth weight, and mode of delivery there was no difference in either the mortality or the incidence of intraventricular haemorrhage in the three study populations. Although there seem to be no distinct advantages of in utero transfer in terms of mortality and morbidity, there are other psychological and emotional advantages.     

Attitudes to viability of preterm infants and their effect on figures for perinatal mortality.

OBJECTIVE--To examine how local attitudes to management of extreme preterm labour can influence data on perinatal mortality. DESIGN--One year prospective study in a geographically defined population. SETTING--The 17 perinatal units of Trent region. PATIENTS--All preterm infants of less than or equal to 32 weeks'' gestation in the Trent region. INTERVENTIONS--Infants who had been considered viable at birth were referred for intensive care; those who had been considered non-viable received terminal care. MAIN OUTCOME MEASURES--Whether each infant was born alive, dead, or alive but considered non-viable. RESULTS--Large differences were observed among units in the rates of delivery of infants of less than or equal to 27 weeks'' gestation (rates varied from 7.2 to 0 per 1000 births). These differences were not present in the data relating to infants of between 28 and 32 weeks'' gestation. The variation seemed to result from different approaches to the management of extreme preterm labour--that is, whether management took place in a labour ward or a gynaecology ward. CONCLUSIONS--Place of delivery of premature babies (less than or equal to 27 weeks'' gestation) may influence classification and hence figures for perinatal mortality. In addition, the fact that the onus of judgment regarding viability and classification is often placed on relatively junior staff might also affect the figures for perinatal mortality. The introduction of a standard recording system for all infants greater than 500 g would be advantageous.     

Epidemiology of spontaneous premature rupture of membranes: factors in pre-term births

The frequency of spontaneous premature rupture of membranes (PROM) was determined in the pregnancies of 1,848 white mothers and their singleton infants, born at the University of Kansas Medical Center between April 1975 and April 1978. The frequency of PROM increased significantly from a low of 34/707 (4.8 percent) among low-risk mothers, to 40/444 (9.0 percent) among mothers smoking one to 60 cigarettes a day, to 21/204 (10.3 percent) among mothers with multiple adverse maternal practices, and to 12/46 (26 percent) among mothers with selected complications of their pregnancies. The proportion of low birth weight (LBW) (less than 2,500 g) pre-term infants born to PROM mothers increased among the risk factor groups in a similar manner, from a low of 2/34 (6 percent) in low-risk pregnancies to 8/40 (20 percent) among mothers smoking one to 60 cigarettes a day, to 7/21 (33 percent) among mothers with multiple adverse practices, and to 7/12 (58 percent) among mothers with selected complications of pregnancy. The increased incidence of low birth weight pre-term infants born to mothers with PROM was associated with evidence of growth retardation among full-term infants in the high-risk groups. This finding was manifested by reductions in mean birth weights of full-term infants born to high-risk mothers but not observed in full-term infants born to low-risk mothers. The attained growth at birth of low birth weight pre-term infants could not be determined, because appropriate birth weight standards for pre-term infants born to mothers with low-risk pregnancies are not available. These results suggest that growth retardation in fetuses increased the probability of the mothers having PROM prior to the onset of labor, and, if PROM did occur, of having a premature delivery. We hypothesize that the tensile strength of the amnion and chorion is diminished by the same conditions that retard fetal growth, and that this reduction in strength of the fetal membranes contributes to premature rupture of membranes and pre-term delivery.     

Effects of placental malaria on mothers and neonates from Zaire

Of one hundred placentas collected consecutively in the Ubangi district, Zaire, 64 had falciparum malaria. Mothers and infants of the 64 malarious and 36 non-malarious placentas were compared. The malarious placentas had no consistent relationship to infant length or head circumference, APGAR score, birthweight, maternal anemia, splenomegaly or hydramnios. The rate of hydramnios, in fact, was higher in the mothers with non-malarious placentas. Mothers with malarious placentas were younger (means 24) than mothers with non-malarious placentas (means 29). Mothers with fewer pregnancies were more likely to have malarious placentas than older multiparous mothers. There were 7 stillbirths, 4 from mothers with malarious placentas. Infants born to mothers with malarious placentas averaged 100 g less than those from mothers with non-malarious placentas. This study shows that mothers with falciparum malaria from the Ubangi district deliver normal and apparently unaffected infants.     

Outcome of infants of very low birth weight: a geographically based study.

The outcome of 143 live-born infants of very low birth weight (defined as less than 1500 g) who were born in 1980-81 to women resident in Newfoundland and Labrador is described. Sixty-one infants (43%) died during the first year of life. Of the 82 surviving infants 79 were followed for 18 months to 3 years. Eight (10%) were found to have evidence of severe neurodevelopmental abnormality, and nine (11%) were found to have various minor problems, including seizures, developmental delay and behavioural disorders. There was an inverse association between birth weight and mortality. Neonatal pneumothorax, seizures and clinical evidence of intraventricular hemorrhage were more commonly seen among infants who died; these factors also seemed to be predictive of an adverse long-term outcome. Continuous monitoring of the rates of death and disability among infants of very low birth weight born within a defined region should provide the basis for rational planning and delivery of neonatal intensive care.     

Vision screening at 8 and 18 months. Steering Committee of Oxford Region Child Development Project.

OBJECTIVE--To determine the effectiveness of an existing screening programme based in the community for ocular and vision defects in infants considered at increased risk of such defects. DESIGN--Children with ocular or vision defect by the age of 2 were ascertained by searching records. Those from populations at high risk were matched with their results from screening tests. The characteristics of the cases among this population were compared with those of the cases in the remainder of the population. Patterns of referral and age at referral were studied in both groups. SETTING--The study was conducted within Oxfordshire Health District. SUBJECTS--433 Children at high risk born in 1984 to mothers living in the health district at delivery and who either weighed less than 2000 g or weighed 2000 g and over and required admission to a special care nursery for longer than 24 hours. The low risk population (6254) were infants without these characteristics who were resident in the health district at the time of referral. INTERVENTIONS--Screening tests for vision or ocular defects already routinely used were applied by health visitors at 8 and 18 months to the children at high risk. MAIN OUTCOME MEASURE--Comparison of results of screening tests with vision and ocular defects detected by the age of 2. RESULTS--Screening tests in current use for vision loss and squint in this age group were insensitive and had a low positive predictive value when applied to a high risk population. Defects that were not apparent on direct inspection were unlikely to be detected by these tests. In the high risk group the relative risk of having a defect was 2.8 (95% confidence interval 1.8 to 4.5) but 85% of all cases detected by the age of 2 were in children at low risk. Referral patterns and age of referral differed in the two groups. CONCLUSIONS--Screening by health visitors of high risk populations contributes little to the detection of vision and ocular defects. This type of evaluation needs to be applied also to low risk populations, who have different referral patterns and contribute most of the cases.     

Decreased incidence of neurologic disability among neonates at high risk born between 1975 and 1984 in Alberta.

We report the outcome at 2 or 3.5 years of 1463 neonates at high risk born between 1975 and 1984 and cared for in a regional perinatal program in Alberta. Although the number of surviving infants of very low birth weight (1250 g or less) increased over the study period, the incidence rate of neurologic impairment fell significantly, from 19% to 13% (p less than 0.01), so that there was no significant increase in the absolute number of disabled children. This finding remained valid when two other groups of infants at high risk (those weighing more than 1250 g at birth and having a positive neurologic history and those born at term with asphyxial encephalopathy) were included in the analysis, so that over the decade there was a significant decrease in the incidence of disability among the total group of neonates (p less than 0.01) and no increase in the absolute number of disabled children (23 in 1975 and 19 in 1984). We conclude that neonatal intensive care has contributed to improved survival of neonates at high risk without increasing the burden of major neurologic disability.     

The epidemiology of white full-term infants with short crown-heel lengths for gestational ages at birth

Fetal growth retardation was diagnosed in 137 (7.8 percent) of 1,757 white full-term infants who had crown-heel lengths below the fifth percentiles for their gestational ages. The incidence of short infants was 121 (11.1 percent) among 1,093 mothers with high-risk pregnancies compared to 16 (2.4 percent) in 664 low-risk mothers (p less than 0.0001). There were four high-risk categories: spontaneous premature rupture of membranes (PROM), fetal conditions, complications of pregnancy, and adverse maternal practices. The incidence of short infants was significantly higher in each of the four high-risk categories than in the low-risk group. There were three other conditions that were present in all pregnancies that were associated with the frequency of short infants: maternal height, socioeconomic status of head of household, and sex of infant. A short maternal height (under 157.7 cm = 62 inches) was significantly associated with an increase in short infants among mothers who smoked cigarettes at any level during pregnancy and among mothers with PROM in combination with other risks, but not in the group of 664 low-risk mothers. Significantly more short girls than short boys were born to mothers who smoked ten or more cigarettes a day throughout pregnancy or who had multiple adverse maternal practices, but no statistically significant differences were noted among mothers who smoked fewer than ten cigarettes per day, among those with PROM as the only risk factor, or among those with medical or obstetrical complications. Moreover, those mothers who were in socioeconomic groups III and IV and had other risk factors had a significantly higher incidence of short infants than did similar mothers in socioeconomic groups I and II.     

Gastroschisis, low maternal age, and fetal morbidity outcomes

OBJECTIVE: To determine if the risk for fetal growth inhibition among gastroschisis-afflicted fetuses is heightened among younger gravidas (teen mothers). METHOD: This was a retrospective cohort study on live-born infants with isolated gastroschisis delivered in New York State from 1983 through 1999. We compared infants of mature (>20 years) mothers with those of younger (<20 years) mothers with respect to the following indices of fetal morbidity outcomes: low birth weight and very low birth weight, preterm and very pre-term, and small for gestational age. We used adjusted odds ratios to approximate relative risks. RESULTS: A total of 368 infants with isolated gastroschisis were analyzed. The two groups differed in terms of mean gestational age at delivery [Mean + standard deviation(SD) for infants with gastroschisis born to mature mothers = 37.2 weeks +/- 2.8 versus 36.3 weeks + 3.6 for those of teenage mothers(p = 0.01)], as well as mean birth weight [mean birth weight +/- SD for infants with gastroschisis born to mature mothers = 2562.4 grams +548.8 versus 2367.9 grams +/- 645.2 for those of younger mothers (p = 0.004)]. Infants of teen mothers were about twice as likely to be of low birth weight (OR = 1.70; 95% CI = 1.05-2.77) and about three times as likely to be born very preterm when compared to those of mature mothers (OR = 2.80; 95% Cl = 1.02-8.00). No significant differences were observed with respect to very low birth weight, pre-term and small for gestational age. CONCLUSION: Low maternal age appears to be a risk factor for low birth weight and very preterm birth among gastroschisis-affected fetuses. This information is potentially useful for planning by care providers and in counseling affected parents.     

Patterns of low birth weight in the Bengali newborns

This paper examines the distribution of low birth weight (2500 g or less) by gestation time, sex, maternal age, parity (birth order), socioeconomic conditions, and season of birth among 5117 single live births born to Bengali mothers at the Ramakrishna Mission Seva Pratisthan Hospital in Calcutta, India. Preterm infants have low birth weight significantly more often than their full term counterparts. Female infants have low birth weights significantly more often than male infants. The infants of poor mothers have lower birth weights in higher order births more often than infants of higher orders born to well-off mothers. Teenaged mothers produce low birth weight babies significantly more often than older mothers. Although the relationship is not significant, low birth weight infants occur more often among 1st and late born infants and less often among 2nd born infants. The season of birth is not significantly associated with birth weight. Less than 10% of low birth weight infants are pre-term, while the rest are full term. The great majority of low birth weight infants are small-for-gestational-age; the minority are small due to curtailed gestational age. The proportion of infants weighing less than 2001 g is only 9%; this figure tallies closely with earlier studies of India.     

Maternal vitamin D intake and mineral metabolism in mothers and their newborn infants.

Pregnant women receiving daily supplements of 400 IU (10 microgram) of vitamin D2 from the 12th week of pregnancy had plasma calcium concentrations higher at 24 weeks but similar at delivery to those in control pregnant women who did not receive the supplements. Infants of the women receiving the supplements had higher calcium, lower phosphorus, and similar magnesium concentrations on the sixth day of life and a lower incidence of hypocalcaemia than infants of the control women. Plasma concentrations of 25-hydroxycholecalciferol, which showed a seasonal variation, were higher in mothers and infants in the treated group. Cord-blood calcium, magnesium, phosphorus, and 25-hydroxycholecalciferol concentrations correlated with maternal values at delivery. Breast-fed infants had higher calcium and magnesium and lower phosphorus and 25-hydroxycholecalciferol concentrations than artificially fed infants. A defect of dental enamel was found in a high proportion of infants (many of whom had suffered from hypocalcaemia) born to the control women. These results suggest that vitamin D supplementation during pregnancy would be beneficial for mothers, whose intake from diet and skin synthesis is appreciably less than 500 IU of vitamin D daily.     

Maternal fatness and viability of preterm infants

To investigate the effect of maternal fatness on the mortality of infants born preterm up to the corrected age of 18 months 795 mother-infant pairs were studied. Maternal fatness was defined by Quetelet''s index (weight/(height²)) and all infants weighed less than 1850 g at birth. In 771 mother-infant pairs maternal age, complications of pregnancy, mode of delivery, parity, social class, and the baby''s sex and gestation were analysed by a logistic regression model for associations with infant mortality (but deaths from severe congenital abnormalities and those occurring during the first 48 hours after birth were excluded). In a subgroup of 284 mother-infant pairs all infant deaths except those from severe congenital abnormalities were analysed in association with the infant''s birth weight and gestation and the mother''s height and weight; this second analysis included another 24 infants who had died within 48 hours after birth. In the first analysis mortality overall was 7% (55/771), rising from 4% (71/173) in thin mothers (Quetelet''s index <20) to 15% (6/40) in mothers with grades II and III obesity (Quetelet''s index >30). After adjusting for major demographic and antenatal factors, including serious complications of pregnancy, maternal fatness was second in importance only to length of gestation in predicting death of infants born preterm. In the second analysis mortality overall was 15% (44/284), rising from 9% (5/53) in thin mothers to 47% (8/17) in mothers with grades II and III obesity. In both analyses the relative risk of death by 18 months post-term was nearly four times greater in infants born to obese mothers than in those born to thin mothers. In addition, maternal fatness was associated with reduced birth weight, whereas it is associated with macrosomia in term infants.These data differ fundamentally from those reported in full term babies of obese mothers. It is speculated that the altered metabolic milieu in obesity may reduce the ability of the fetus to adapt to extrauterine life if it is born preterm.     

Sudden infant death syndrome and postneonatal mortality in immigrants in England and Wales.

To examine ethnic differences in postneonatal mortality and the incidence of sudden infant death in England and Wales during 1982-5 records were analysed, the mother''s country of birth being used to determine ethnic group. Postneonatal mortality was highest in infants of mothers born in Pakistan (6.4/1000 live births) followed by infants of mothers born in the Caribbean (4.5) and the United Kingdom and Republic of Ireland (4.1). Crude rates were lower in infants of mothers born in India (3.9/1000), east and west Africa (3.0), and Bangladesh (2.8) than in infants of mothers born in the United Kingdom despite less favourable birth weights. Mortality ratios standardised separately for maternal age, parity, and social class were significantly higher in infants of mothers born in Pakistan and lower in those of mothers born in Bangladesh. The ratio for infants of Caribbean mothers was significantly higher when adjusted for maternal age. Ratios for infants of Indian and east African mothers did not show significant differences after standardisation. An important finding was a low incidence of sudden infant death in infants of Asian origin. This was paralleled by lower mortality from respiratory causes. During 1975-85 postneonatal mortality in all immigrant groups except Pakistanis fell to a similar or lower rate than that in the United Kingdom group; Pakistanis showed a persistent excess. During 1984-5 several immigrant groups (from the Republic of Ireland, India, west Africa, and the Caribbean) recorded an increase in postneonatal mortality. Surveillance of postneonatal mortality among ethnic communities should be continued, and research is needed to identify the causes underlying the differences.     

Survival of extremely premature babies in a geographically defined population: prospective cohort study of 1994-9 compared with 2000-5

Objective To assess changes in survival for infants born before 26 completed weeks of gestation.Design Prospective cohort study in a geographically defined population.Setting Former Trent health region of the United Kingdom.Subjects All infants born at 22+0 to 25+6 weeks’ gestation to mothers living in the region. Terminations were excluded but all other births of babies alive at the onset of labour or the delivery process were included.Main outcome measures Outcome for all infants was categorised as stillbirth, death without admission to neonatal intensivecare, death before discharge from neonatal intensivecare, and survival to discharge home in two time periods: 1994-9 and 2000-5 inclusive.Results The proportion of infants dying in delivery rooms was similar in the two periods, but a significant improvement was seen in the number of infants surviving to discharge (P<0.001). Of 497 infants admitted to neonatal intensive care in 2000-5, 236 (47%) survived to discharge compared with 174/490 (36%) in 1994. These changes were attributable to substantial improvements in the survival of infants born at 24 and 25 weeks. During the 12 years of the study none of the 150 infants born at 22 weeks’ gestation survived. Of the infants born at 23 weeks who were admitted to intensive care, there was no significant improvement in survival to discharge in 2000-5 (12/65 (18%) in 2000-5 v 15/81 (19%) in 1994-9).Conclusions Survival of infants born at 24 and 25 weeks of gestation has significantly increased. Although over half the cohort of infants born at 23 weeks wasadmitted to neonatalintensive care, there was no improvement in survival at this gestation. Care for infants born at 22 weeks remained unsuccessful.     

Experience with fetal monitoring in a university teaching hospital.

Fetal monitoring during labour may be expected to decrease perinatal losses and the number of infants born with brain damage. In a prospective study of intrapartum fetal monitoring in selected high-risk pregnancies in a Winnipeg hospital the monitoring rate was 26.5% and the cesarean section rate in the monitored group was 22.0%. The fetal outcome in the monitored group was better than in the unmonitored group. The establishment of a fetal intensive care unit is believed to be strongly desirable in improving fetal surveillance during labour. Fetal monitors should be stationed in the delivery room as well as in the first-stage room.     

Spontaneous preterm labour and delivery at under 34 weeks' gestation.

The management and outcome of 242 infants delivered between 26 and 34 weeks'' gestation in an obstetrical and neonatal regional referral centre as a result of spontaneous preterm labour were recorded prospectively. Results of the survey show that the decision to intervene and delay delivery will depend on the availability of neonatal intensive care facilities. Infants likely to require intensive neonatal care should be transferred in utero to a centre with these facilities. The use of steroids reduces the mortality of preterm infants. The maximum effect occurs between 30 and 32 weeks'' gestation, and there is no benefit after 34 weeks. If the weight is over 1500 g the mode of delivery of the preterm infant presenting by the breech does not influence outcome; if under 1500 g a caesarean section improves survival over those infants born by vaginal breech delivery.     

Costs and benefits of a community special care baby service

Between January 1981 and December 1986 3829 low birthweight (<2500 g) infants and 1980 other high risk infants were cared for at home after they were discharged from hospital by a specialist neonatal nursing service. Of the infants who were referred to this service, 720 (12%) weighed under 2000 g and 1919 (33%) under 2250 g at the time of discharge home. The infants were visited by the community neonatal sisters on an average of 11 occasions, but the number of visits varied from six to over 100 depending on the needs of the child and parents. There was close liaison with other community and hospital staff. Two hundred and thirty (4%) referred infants were readmitted to hospital while under the care of the specialist nursing service. In 1985 the cost of the service was £127 000, or £123 for each infant referred. Providing this specialist support at home allowed much earlier discharge of low birthweight infants from hospital. When compared with the cost of providing continuing inpatient neonatal care earlier discharge was estimated to have saved roughly £250 000 in 1985.Low birthweight infants have an increased risk of serious illness or death that extends beyond the neonatal period. Many are born to young and socially disadvantaged parents who can benefit from expert guidance and support at home. A community neonatal nursing service has advantages for high risk infants and their parents, is cost effective, and allows more efficient use of limited hospital resources.     

The influence of antenatal and maternal factors on stillbirths and neonatal deaths in New South Wales, Australia

This study identified the influences of maternal socio-demographic and antenatal factors on stillbirths and neonatal deaths in New South Wales, Australia. Bivariate and multivariate analyses were used to explore the association of selected antenatal and maternal characteristics with stillbirths and neonatal deaths. The findings of this study showed that stillbirths and neonatal deaths significantly varied by infant sex, maternal age, Aboriginality, maternal country of birth, socioeconomic status, parity, maternal smoking behaviour during pregnancy, maternal diabetes mellitus, maternal hypertension, antenatal care, plurality of birth, low birth weight, place of birth, delivery type, maternal deaths and small gestational age. First-born infants, twins and infants born to teenage mothers, Aboriginal mothers, those who smoked during the pregnancy and those of lower socioeconomic status were at increased risk of stillbirths and neonatal deaths. The most common causes of stillbirths were conditions originating in the perinatal period: intrauterine hypoxia and asphyxia. Congenital malformations, including deformities and chromosomal abnormalities, and disorders related to slow fetal growth, short gestation and low birth weight were the most common causes of neonatal deaths. The findings indicate that very low birth weight (less than 2,000 g) contributed 75.6% of the population-attributable risks to stillbirths and 59.4% to neonatal deaths. Low gestational age (less than 32 weeks) accounted for 77.7% of stillbirths and 87.9% of neonatal deaths. The findings of this study suggest that in order to reduce stillbirths and neonatal deaths, it is essential to include strategies to predict and prevent prematurity and low birth weight, and that there is a need to focus on anti-smoking campaigns during pregnancy, optimizing antenatal care and other healthcare programmes targeted at the socially disadvantaged populations identified in this study.     

Weight growth in infants born to mothers who smoked during pregnancy.

OBJECTIVE--To determine whether maternal smoking during pregnancy causes impairment in growth after birth. DESIGN--Longitudinal study. SETTING--Six medical university centres of six towns of north, central, and south Italy. SUBJECTS--12,987 babies (10,238 born from non-smoking mothers, 2276 from mothers smoking one to nine cigarettes a day, and 473 from mothers smoking > or = 10 cigarettes a day) entered the study. MAIN OUTCOME MEASURES--Difference in weight gain between children born to smoking mothers and those born to non-smoking mothers. Weight was measured at birth and at 3 and 6 months of age. Maternal smoking habit was derived from interview on third or fourth day after delivery. RESULTS--Compared with children born to mothers who did not smoke during pregnancy, the birth weights of children born to mothers who smoked up to nine cigarettes a day were 88 g (girls) and 107 g (boys) lower; in children born to mothers who smoked > or = 10 cigarettes a day weights were 168 g and 247 g lower. At six months of age for the first group the mean weight for girls was 9 g (95% confidence interval -47 g to 65 g) higher and for boys 64 g (-118 g to -10 g) lower than that of children born to mothers who did not smoke. The corresponding figures for the second group were 28 g (-141 g to 85 g) lower for girls and 24 g (-136 g to 88 g) lower for boys. CONCLUSIONS--The deficits of weight at birth in children born to mothers who smoked during pregnancy are overcome by 6 months of age. These deficits are probably not permanent when smoking habit during pregnancy is not associated with other unfavourable variables (such as lower socioeconomic class).