Influence of birth weight on differences in infant mortality by social class and legitimacy.

OBJECTIVE--To investigate the influence of birth weight on the pronounced social class differences in infant mortality in Britain. DESIGN--Analysis of routine data on births and infant deaths. SETTING--England and Wales. SUBJECTS--All live births and infant deaths, 1983-5. MAIN OUTCOME MEASURE--Mortality in infants by social class, birth weight, and legitimacy according to birth and death certificates. RESULTS--Neonatal and postneonatal mortality (deaths/1000 births) increased with social class. Neonatal and postneonatal mortality was 4.2/1000 and 2.3/1000 respectively for social class I and 6.8/1000 and 5.6/1000 respectively for social class V. Mortality was lower among births registered within marriage (postneonatal 3.5/1000; neonatal 5.2/1000) than among those jointly registered outside marriage (5.1/1000; 6.4/1000); mortality was highest in those solely registered outside marriage (7.2/1000; 7.0/1000). For neonatal mortality the effect of social class varied with birth weight. Social class had little effect on neonatal mortality in low birthweight babies and increasing effect in heavier babies. For postneonatal mortality the effect of social class was similar for all birth weights and was almost as steep as for all birth weights combined. CONCLUSION--Birth weight mediates little of the effect of social class on postneonatal mortality.     

Fetal and neonatal mortality: a matter of care? Report of a survey in Cura?ao,Netherlands Antilles.

A detailed clinicopathological analysis of 223 consecutive fetal and neonatal deaths was carried out in Curaçao during 1984 and 1985; this included careful histological examination of 210 infants (94%). The crude death rate was 34.2 per 1000 total births. Malformation was the principal cause of death in 28 cases, antepartum haemorrhage in 19, hypertension in 25, and asphyxia in 35. Death was caused by problems of preterm birth in 68 cases. No specific cause could be found for 34 deaths. Improvement in the quality of obstetric care might substantially reduce both fetal and neonatal death rates.     

Contribution of twin pregnancy to perinatal mortality and fetal growth retardation; reversal of growth retardation after birth.

A survey of factors associated with perinatal mortality in 511 twins and fetal growth retardation and its reversal in 262 twins is presented. The incidence of stillbirth was almost 50% higher in twins than in singletons and the neonatal mortality was six times as high. Eighty percent of the neonatal deaths occurred in infants born prior to or at 30 weeks of gestation; 93% of the deaths were in infants weighing less than 1500 g and 75% occurred within 48 hours of birth. Fetal malnutrition was the main cause of stillbirth, and respiratory distress syndrome and asphyxia neonatorum were the main causes of neonatal death. One quarter of the twins had fetal growth retardation, a prevalence 10 times that in singletons. In almost all, the growth retardation was reversed by high-energy feedings. Although twins represented only 1% of all pregnancies and 2% of live births, they composed 12% of infants with early neonatal death and 17% of growth-retarded infants. A program is suggested for reduction of twin mortality and morbidity.     

Why Are Babies Dying in the First Month after Birth? A 7-Year Study of Neonatal Mortality in Northern Ghana

Objectives

To determine the neonatal mortality rate in the Kassena-Nankana District (KND) of northern Ghana, and to identify the leading causes and timing of neonatal deaths.

Methods

The KND falls within the Navrongo Health Research Centre’s Health and Demographic Surveillance System (HDSS), which uses trained field workers to gather and update health and demographic information from community members every four months. We utilized HDSS data from 2003–2009 to examine patterns of neonatal mortality.

Results

A total of 17,751 live births between January 2003 and December 2009 were recorded, including 424 neonatal deaths 64.8%(275) of neonatal deaths occurred in the first week of life. The overall neonatal mortality rate was 24 per 1000 live births (95%CI 22 to 26) and early neonatal mortality rate was 16 per 1000 live births (95% CI 14 to 17). Neonatal mortality rates decreased over the period from 26 per 1000 live births in 2003 to 19 per 1000 live births in 2009. In all, 32%(137) of the neonatal deaths were from infections, 21%(88) from birth injury and asphyxia and 18%(76) from prematurity, making these three the leading causes of neonatal deaths in the area. Birth injury and asphyxia (31%) and prematurity (26%) were the leading causes of early neonatal deaths, while infection accounted for 59% of late neonatal deaths. Nearly 46% of all neonatal deaths occurred during the first three postnatal days. In multivariate analysis, multiple births, gestational age <32 weeks and first pregnancies conferred the highest odds of neonatal deaths.

Conclusions

Neonatal mortality rates are declining in rural northern Ghana, with majority of deaths occurring within the first week of life. This has major policy, programmatic and research implications. Further research is needed to better understand the social, cultural, and logistical factors that drive high mortality in the early days following delivery.     

Perinatal mortality and one-year infant morbidity.

Perinatal mortality in Southampton and South-west Hampshire Health District fell from 20.8 per 1000 total births in 1970 to 11.3 per 1000 in 1976. This was atributable mainly to a fall in the stillbirth rate, but also to a recent fall in the neonatal death rate in the first week. All infants born in 1975 who had any problems in the perinatal period were followed up for one year. Of the 12 children identified at one year as having a major handicap, eight suffered from problems of prenatal origin, two from problems associated with preterm delivery, and two from other conditions acquired during the perinatal period. As two-thirds of the major handicaps arose from congenital abnormalities, preterm delivery and low birth weight were not the main causes of major handicap.     

Evaluating perinatal mortality rates: effects of referral and case mix.

OBJECTIVE--To evaluate perinatal mortality rates as a method of auditing obstetric and neonatal care after account had been taken of transfer between hospitals during pregnancy and case mix. DESIGN--Case-control study of perinatal deaths. SETTING--Leicestershire health district. SUBJECTS--1179 singleton perinatal deaths and their selected live born controls among 114,362 singleton births to women whose place of residence was Leicestershire during 1978-87. MAIN OUTCOME MEASURE--Crude perinatal mortality rates and rates adjusted for case mix. RESULTS--An estimated 11,701 of the 28,750 women booked for delivery in general practitioner maternity units were transferred to consultant units during their pregnancy. These 11,701 women had a high perinatal mortality rate (16.8/1000 deliveries). Perinatal mortality rates by place of booking showed little difference between general practitioner units (8.8/1000) and consultant units (9.3-11.7/1000). Perinatal mortality rates by place of delivery, however, showed substantial differences between general practitioner units (3.3/1000) and consultant units (9.4-12.6/1000) because of the selective referral of high risk women from general practitioner units to consultant units. Adjustment for risk factors made little difference to the rates except when the subset of deaths due to immaturity was adjusted for birth weight. CONCLUSION--Perinatal mortality rates should be adjusted for case mix and referral patterns to get a meaningful result. Even when this is done it is difficult to compare the effectiveness of hospital units with perinatal mortality rates because of the increasingly small subset of perinatal deaths that are amenable to medical intervention.     

Perinatal mortality and adverse pregnancy outcomes in a low-income rural population of women who smoke

We describe adverse pregnancy outcomes, including congenital anomalies, fetal, neonatal, and infant mortality among a Missouri population of low-income, rural mothers who participated in two randomized smoking cessation trials. In the Baby BEEP (BB) trial, 695 rural women were recruited from 21 WIC clinics with 650 women's pregnancy outcomes known (93.5% retention rate). Following the BB trial, 298 women who had a live infant after November 2004 were recruited again into and completed the Baby Beep for Kids (BBK) trial. Simple statistics describing the population and perinatal and postneonatal mortality rates were calculated. Of the adverse pregnancy outcomes (n = 79), 29% were spontaneous abortions of less than 20 weeks' gestation, 23% were premature births, and 49% were identified birth defects. The perinatal mortality rate was 15.9 per 1000 births (BB study) compared with 8.6 per 1000 births (state of Missouri) and 8.5 per 1000 births (United States). The postneonatal infant mortality rate was 13.4 per 1000 live births (BBK) compared with 2.1 per 1000 live births (United States). The health disparity in this population of impoverished, rural, pregnant women who smoke, particularly in regard to perinatal and infant deaths, warrants attention.     

Is perinatal care in southwestern Ontario regionalized?

OBJECTIVE: To determine whether perinatal care in southwestern Ontario is regionalized, to identify trends over time in referral patterns, to quantify trends in perinatal death rates and to identify trends in perinatal death rates that give evidence of regionalization. DESIGN: Cohort study. SETTING: Thirty-two hospitals in southwestern Ontario (1 level III, 1 modified level III and 30 level II or I). PATIENTS: All pregnant women admitted to the hospitals and their infants. MAIN OUTCOME MEASURES: Antenatal and neonatal transfer status, live-born with discharge home alive from hospital of birth, stillborn, and live-born with death before discharge. RESULTS: Between 1982 and 1985 the antenatal transfer rate increased from 2.2% to 2.8% (p less than 0.003). The proportion of births of infants weighing 500 to 1499 g increased from 49% to 69% at the level III hospital. The neonatal transfer rate increased from 26.2% to 47.9% (p less than 0.05) for infants in this birth-weight category and decreased from 10.2% to 7.1% (p less than 0.03) for infants weighing 1500 to 2499 g. The death rate among infants of low birth weight was lowest among those born at the level III centre and decreased at all centres between 1982 and 1985. CONCLUSIONS: Perinatal care in southwestern Ontario is regionalized and not centralized; regionalization in southwestern Ontario increased between 1982 and 1985.     

Contribution of preterm delivery to perinatal mortality.

A detailed retrospective analysis was made of the records of 486 preterm infants, who accounted for 5-1% of all births during 1973 and 1974. Whereas preterm delivery did not contribute to perinatal mortality in terms of stillbirth, it outweighed all other causes in terms of early neonatal deaths. Preterm birth was responsible for 85% of the early neonatal deaths not due to lethal congenital deformities. Early neonatal mortality rates were closely linked both to gestational age and birth weight and to the reason for preterm birth. Early neonatal mortality was high (97 per 1000) when preterm labour was spontaneous, whether or not associated with material or fetal disease or with multiple pregnancy, but low (27 per 1000) when preterm delivery was elective. Preventing spontaneous preterm labour would considerably reduce neonatal mortality in our community.     

Perinatal mortality and adverse pregnancy outcomes in a low‐income rural population of women who smoke

We describe adverse pregnancy outcomes, including congenital anomalies, fetal, neonatal, and infant mortality among a Missouri population of low‐income, rural mothers who participated in two randomized smoking cessation trials. In the Baby BEEP (BB) trial, 695 rural women were recruited from 21 WIC clinics with 650 women's pregnancy outcomes known (93.5% retention rate). Following the BB trial, 298 women who had a live infant after November 2004 were recruited again into and completed the Baby Beep for Kids (BBK) trial. Simple statistics describing the population and perinatal and postneonatal mortality rates were calculated. Of the adverse pregnancy outcomes (n = 79), 29% were spontaneous abortions of less than 20 weeks' gestation, 23% were premature births, and 49% were identified birth defects. The perinatal mortality rate was 15.9 per 1000 births (BB study) compared with 8.6 per 1000 births (state of Missouri) and 8.5 per 1000 births (United States). The postneonatal infant mortality rate was 13.4 per 1000 live births (BBK) compared with 2.1 per 1000 live births (United States). The health disparity in this population of impoverished, rural, pregnant women who smoke, particularly in regard to perinatal and infant deaths, warrants attention. Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.     

Perinatal mortality: a continuing collaborative regional survey.

A collaborative survey of perinatal mortality in each district of the Northern region set up in July 1980 was able to obtain information on 99% of all the registered perinatal deaths among babies born in 1981-2 to mothers resident in the region. There were 12.4 perinatal deaths/1000 births over this two year period, but 41% of the stillbirths and early neonatal deaths were of babies with a lethal malformation or weighing less than 1000 g at birth (or both). All causes of perinatal mortality had become less common than they had been at the time of the National Birthday Trust survey in 1958, though there had been a relatively small decrease in the number of deaths due to malformation (in the absence of any neural tube defect) and in the number of stillbirths of normally developed fetuses: 36% of the antepartum stillbirths among non-malformed singleton fetuses were associated with poor fetal growth (weight below the fifth centile at birth) and 21% were due to sudden unexplained placental abruption.     

Confidential paediatric inquiry into neonatal deaths in Wessex, 1981 and 1982.

From 1 January 1981 to 31 December 1982, 66 256 births and 386 neonatal deaths were recorded in the Wessex Regional Health Authority, giving a neonatal mortality of 5.8/1000 live births. An experienced consultant paediatrician undertook a confidential inquiry into each death shortly after it had been reported. One hundred and forty four deaths (37%) were found to be due to lethal or severe malformations, an incidence of 2.2/1000 births. Of the 242 normally formed infants, 111 (46%) died within 24 hours of birth. Seventy seven (32%) weighed over 2500 g at birth. Factors operating before delivery accounted for 104 (43%) of the deaths of normally formed infants. The commonest factors were short gestation and low birth weight, and intrauterine hypoxia and birth injury. Factors after delivery accounted for 81 deaths (33%), the commonest being infections and sudden infant deaths. In the remaining 57 deaths (24%) it seemed that a combination of factors before and after birth had led to the death. Factors before birth thus played a part in two thirds of all deaths. Possible adverse factors in medical care were sought in 154 potentially viable babies and were identified in 38--that is, 10% of all neonatal deaths. Better provision and training of district staff in immediate care at birth would achieve more in lowering neonatal mortality in Wessex than the setting up of a regional unit specializing in advanced neonatal intensive care. Moreover, the greatest scope for improving the outcome of childbirth in Wessex would be offered if there were further advances in obstetric rather than neonatal care.     

Outcomes of planned home births with certified professional midwives: large prospective study in North America

Objective To evaluate the safety of home births in North America involving direct entry midwives, in jurisdictions where the practice is not well integrated into the healthcare system.Design Prospective cohort study.Setting All home births involving certified professional midwives across the United States (98% of cohort) and Canada, 2000.Participants All 5418 women expecting to deliver in 2000 supported by midwives with a common certification and who planned to deliver at home when labour began.Main outcome measures Intrapartum and neonatal mortality, perinatal transfer to hospital care, medical intervention during labour, breast feeding, and maternal satisfaction.Results 655 (12.1%) women who intended to deliver at home when labour began were transferred to hospital. Medical intervention rates included epidural (4.7%), episiotomy (2.1%), forceps (1.0%), vacuum extraction (0.6%), and caesarean section (3.7%); these rates were substantially lower than for low risk US women having hospital births. The intrapartum and neonatal mortality among women considered at low risk at start of labour, excluding deaths concerning life threatening congenital anomalies, was 1.7 deaths per 1000 planned home births, similar to risks in other studies of low risk home and hospital births in North America. No mothers died. No discrepancies were found for perinatal outcomes independently validated.Conclusions Planned home birth for low risk women in North America using certified professional midwives was associated with lower rates of medical intervention but similar intrapartum and neonatal mortality to that of low risk hospital births in the United States.     

Population based ascertainment of twins and their siblings, born in Western Australia 1980 to 1992, through the construction and validation of a maternally linked database of siblings.

This paper describes the creation of a unique maternal identifier for use in the investigation of perinatal, postneonatal and child outcomes in relation to maternal characteristics. All Midwives' records of Western Australian (WA) births were routinely linked to registrations of births and deaths for infants born from 1980 to 1992 inclusive, then linked to WA hospital discharge data and to registries of birth defects and cerebral palsy to create a longitudinal health record for each infant. However, since each birth to a woman was recorded as a separate event, there was no way to identify siblings. Probabilistic record linkage, based on information about the mother, was used for this task. Logical inconsistencies within the data were used to test the validity of the linkages between birth records attributed to each mother. Information about the mother from other epidemiological studies and data abstracted from hospital case notes was also used to validate sibships. Linkage of the records of 310,255 births in WA during that period resulted in the formation of 181,133 sibships of one or more children. Pooling the results of all of the validation methods gave an error of 0.9%. Linkage identified 3678 sibships containing multiple births, and 305 sets of maternal twins. Ascertainment of twins and their siblings for an ongoing twin register, the WA Twin Child Health (WATCH) study, was a natural consequence of this process.     

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.     

The effect of divorce on infant mortality in a remote area of Bangladesh

The process of divorce is usually lengthy and hazardous, and can start quarrels that can lead to the abuse of women and their children. This study examines the effects of divorce on neonatal and postneonatal mortality of babies born before and after divorce in Teknaf, a remote area of Bangladesh. The longitudinal demographic surveillance system (DSS) followed 1,762 Muslim marriages in 1982-83 for 5 years to record divorce, deaths of spouse, emigration and births. It recorded 2,696 live births during the follow-up period, and their survival status during infancy. Logistic regression models were used to estimate the effect of divorce on neonatal and postneonatal mortality, controlling for maternal age at birth, parity, sex of the child and household economic status. The odds of neonatal and postneonatal deaths among babies born after divorce or less than 12 months before mothers were divorced were more than double the odds of those born to mothers of intact marriages. The odds of postneonatal deaths were two times higher among babies born more than 12 months before divorce happens than their peers. The high mortality of infants born before and after mothers were divorced may reflect how abusive marriage and divorce increase the vulnerability of women and children in rural Bangladesh. Divorce and abuse of women are difficult and intractable social and health problems that must be addressed.     

Perinatal mortality rates in isolated general practitioner maternity units.

OBJECTIVE--To determine the perinatal mortality rate among normally formed, singleton babies with birth weights greater than or equal to 2500 g in Bath health district based on the intended place of delivery at the time of onset of labour or at the time of diagnosis of intrauterine death. DESIGN--The numbers of live births and stillbirths were collected monthly returns from the maternity units concerned. Deaths of infants aged less than or equal to 1 week were collected in the same returns. The intended place of delivery was confirmed at the monthly perinatal mortality meeting, during which maternal and fetal factors were discussed. SETTING--A rural health district of 400,000 population where one third of all deliveries occurred in seven isolated general practitioner maternity units, 8% in the integrated general practitioner unit, and the remainder in the consultant unit. SUBJECTS--All babies of women whose deliveries were booked in the district before the onset of labour or the diagnosis of intrauterine death, excluding twins, babies with lethal congenital malformations, and those less than 2500 g. MAIN OUTCOME MEASURES--Outcome of all deliveries and parity of mothers. RESULTS--14,415 Deliveries were analysed. The perinatal mortality rate was 2.8/1000 births in the consultant unit (7950 deliveries), 4.8 in the isolated general practitioner units (5237 deliveries), and zero in the integrated general practitioner unit (1228 deliveries). Perinatal deaths attributable to asphyxia were more common in the isolated general practitioner units (1.5 per 1000) than the consultant unit (0.6 per 1000). The perinatal mortality rate among babies born to nulliparous women was 3.2/1000 births in the consultant unit and 5.7 in the isolated general practitioner units; for those born to multigravid women it was 2.4 and 4.2 respectively. CONCLUSIONS--The outcome of delivery was not influenced by parity. Both antenatal and intrapartum care were responsible for the higher perinatal mortality rate in the isolated general practitioner units. The integrated unit, which shared midwifery staff with the consultant unit, seemed to work well. Analysis by intended place of delivery at the time of onset of labour or diagnosis of intrauterine death suggested that the care given in isolated units needs to be improved, perhaps by better training of general practitioners and consultant supervision of antenatal care.     

Twins,triplets, and cerebral palsy in births in Western Australia in the 1980s.

OBJECTIVES--To examine the rate of cerebral palsy in twins and triplets in births from 1980 to 1989 in Western Australia and to identify factors associated with increase in risk. DESIGN--Pluralities for all births in Western Australia were identified through the standardised midwives'' notification system, and cases of cerebral palsy were identified from the Western Australian cerebral palsy register. MAIN OUTCOME MEASURES--Multiple births, cerebral palsy, excluding postneonatal cause. RESULTS--The prevalence of cerebral palsy in triplets, of 28 per 1000 survivors to 1 year (95% confidence interval 11 to 63) exceeded that in twins (7.3; 5.2 to 10) and singletons (1.6; 1.4 to 1.8). Although twins and triples were more likely than singletons to be low in birth weight, their risks of cerebral palsy if low in birth weight were similar. In contrast, in normal birthweight categories twins had a higher rate of cerebral palsy (4.2; 2.2 to 7.7) than singletons (1.1; 1.0 to 1.3). The prevalence of cerebral palsy was similar in twins of unlike sex pairs, all of whom are dizygotic, and in like sex pairs. A twin pair in which one member died in utero was at higher risk of cerebral palsy: 96 per 1000 twin pairs (36 to 218) compared with 12 (8.2 to 17) for twin pregnancies in which both survived. There was a similar but non-significant trend for death of one triplet to be associated with increased risk of cerebral palsy in the survivors of the set. CONCLUSION--Triplet pregnancies produced a child with cerebral palsy 47 times more often than singleton pregnancies did and twin pregnancies eight times more often. Eighty six per cent of cerebral palsy in multiple births was in twins. As multiple births are increasing mainly because of personal and medical decisions the increased risk of cerebral palsy in multiple births is of concern.     

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.