Errors in birth registrations and coding of twins and higher order multiples.

Dizygotic compared with monozygotic conceptions are at decreased risk of fetal and infant death and serious morbidity in surviving infants. Different sex twin maternities must be dizygotic but miscoding and incorrect registration of sex and number of fetuses may lead to an incorrect assignment of zygosity. The aim of the study was to validate the coding and registration of number and sex of births in multiple pregnancies. Fetal and infant death registrations from all multiple maternities in England and Wales 1993-1998 were examined. There were 51,792 twin, 1627 triplet and 51 higher order multiple maternities that were registered. Among these there were 1926 fetal deaths, 58 of which were registered as being of indeterminate sex but were coded as male in 56 and female in 2 cases. A fetus papyraceous was registered as male in 19 and as female in 19 cases. Other fetal deaths weighing >/= 100g, with no mention of papyraceous on the death certificate, nevertheless, likely to be of indeterminate sex, were registered as male in 26 and as female in 23 cases. In 13 maternities, the number of infants registered at birth was less than the number mentioned on the registration certificate. It cannot be assumed that multiple births of different registered sex are dizygotic. As surviving infants from a monozygotic multiple birth are at much greater risk of infant death and serious morbidity than dizygotic multiple births, incorrect assignment of sex has important implications for parental counselling and may have medico-legal relevance when attributing negligence as the cause of morbidity in a survivor from a multiple pregnancy.     

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.     

Diurnal births and perinatal behavior among wild patas monkeys: Evidence of an adaptive pattern

Data from a 2-year field study of patas monkeys (Erythrocebus patas) in Kenya support our earlier suggestion that diurnal births are a species-typical pattern of patas. In this respect patas are very unusual, as all existing information shows that nocturnal births are typical of both captive and freeranging monkeys. Patas do not give birth at night because to do so would render ineffective their night-resting strategy which reduces vulnerability to predation at night. Giving birth during the day, however, does not eliminate the risk of being preyed on; nor are all times of day equally favorable for giving birth. Our field data suggest that a patas female gives birth at those times of day when she is least likely to lose contact with her group or to encounter predators.     

A study of infant mortality and causes of death in a rural north-east Brazilian community

In 1984 a prospective study of 1645 women and 1677 births in a rural community in north-eastern Brazil showed the infant mortality rate to be 65 per 1000 live births. Neonatal, post-neonatal and infant mortality are analysed to determine the most important risk factors for each period. Post-neonatal survival depends largely on factors relating to child care, while neonatal deaths are more likely to be associated with biological factors. The principal cause of death, diarrhoeal disease, was responsible for a third of the deaths.     

Effect of birth spacing on infant and child mortality in rural Nepal

This examination of the effect of birth spacing on infant and child mortality in rural Nepal is based on data from the Nepal Fertility Survey 1976 carried out by the Nepal Family Planning and Maternal Child Health Project in collaboration with the World Fertility Survey. The study confirms that the higher risk of infant death to 1st born children is mainly due to the higher proportion of younger women having 1st births, rather than due to their being 1st order births per se. The effect of maternal age on infant and child mortality is largely associated with birth interval. Previous birth interval, therefore, stands out as the most important factor affecting infant mortality; the next most important factor is the survival of the preceding child. A child born after an interval of less than 18 months since the previous live birth has a 31% higher risk of dying during infancy than 1 born after an interval of 1 1/2 to 2 years. The risk of the index child's dying is only 50% of that when its preceding sibling is dead. Neither education of mother nor education of father has a significant effect on infant mortality in rural Nepal.     

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.     

Increasing pre-term and low-birth-weight rates over time and their impact on infant mortality in south-east Brazil

This study investigates the possible effects of pre-term births and low birth weight on infant mortality rates (IMRs) over a 15-year period in Ribeir?o Preto, Brazil, based on surveys carried out in 1978/79 and 1994. The 1978/79 survey included 6750 births over a 12-month period and the 1994 survey 2846 births over a 4-month period. Infant deaths were retrieved monthly from the city register. Infant mortality rate decreased from 36.6 to 16.9 deaths per 1000 over 15 years. The decrease in IMR was larger in the 2500-2999 g group than in any other group. The observed falls in IMR were attributable to decreases in birth-weight-specific mortality rates. Likewise, there was a general decrease in IMR in mild, moderate and severe pre-term births. The incidence rate ratio of infant mortality between surveys was 0.46 (95% CI 0.34-0.63); it increased to 0.57 (95% CI 0.35-0.75) when adjusted for birth weight and other factors in the model and rose to 0.69 (95% CI 0.49-0.97) when adjusted for length of gestation and other variables. The increase in pre-term births and low birth weight may have had, at most, a marginal effect on the IMR. Progress in the care of newborns may have decreased the mortality risk, but even mild pre-term birth still has an impact on infant mortality. There is room for further improvement in IMR by tackling the high rates of pre-term birth.     

Birth interval, mortality and growth of children in a rural area in Kenya

The impact of the length of birth intervals on mortality and growth of children from the perinatal period to 2 years in the Northern Division of Machakos District, Eastern Province, Kenya, were analyzed. There are 2 types of birth intervals: 1) the prospective birth interval--between the birth concerned (the 1st birth of the interval pair) and the subsequent birth; and 2) the retrospective birth interval--between the birth considered (the 2nd of the interval pair) and the preceeding birth. This study includes 3019 women who had at least 1 live birth between April, 1974 and April, 1981. They gave birth to 6778 children (including stillbirths). Births occurring in 1974 are excluded in the analysis because of considerable underregistration. 102 stillbirths and 213 deaths in the 1st 2 years are analyzed. They have been grouped into deaths during the perimatal period; the 1st year after the 1st week of life (infant period); and the 2nd year of life. The most convient method of analysis of the relation between retrospective birth interval and mortality is multivariate analysis, as the intermedicate biological and behavioral factors through which birth intervals can affect health are simultaneously influenced by other variables like maternal age and birth order; the log linear model is applied here. The probability of dying is the dependent variable. The impact of short prospective intervals are closely associated. Only infant and child deaths occurring after the conception of the next child are included. The size of cohorts in which these deaths occur can be calculated with a life table approach. The mortality probability between 5 and 12 months for children with short prospective intervals is .034. This is higher than the corresponding rate for all children in the area (P0.05). It is shown that children with short retrospective or prospective birth intervals do not run a greater risk of mortality or growth retardation than children with longer intervals, neither during the perinatal period nor during the 1st 2 years of life.     

Using birth defects registry data to evaluate infant and childhood mortality associated with birth defects: an alternative to traditional mortality assessment using underlying cause of death statistics

BACKGROUND: Although birth defects are a leading cause of death in infancy and early childhood, the proportion of all deaths to children with clinically diagnosed birth defects is not well documented. The study is intended to measure the proportion of all deaths to infants and children under age 10 occurring to children with birth defects and how and why this proportion differs from the proportion of deaths due to an underlying cause of congenital anomalies using standard mortality statistics. METHODS: A linked file of Michigan livebirths and deaths was combined with data from a comprehensive multisource birth defects registry of Michigan livebirths born during the years 1992 through 2000. The data were analyzed to determine the mortality rate for infants and children with birth defects and for children with no reported birth defect. Mortality risk ratios were calculated. The underlying causes of death for children with birth defects were also categorized and compared to cause- specific mortality rates for the general population. RESULTS: Congenital anomalies were the underlying cause of death for 17.8% of all infant deaths while infants with birth defects were 33.7% of all infant deaths in the study. Almost half of all Michigan deaths to children aged 1 to 2 were within the birth defects registry, though only 15.0% had an underlying cause of death of a congenital anomaly based upon standard mortality statistics. The mortality experience among children with birth defects was significantly higher than other children throughout the first 9 years of life, ranging from 4.6 for 5 year olds to 12.8 for children 1 to 2. Mortality risk ratios examined by cause of death for infants with birth defects were highest for other endocrine (28.1), other CNS (28.1), and heart (21.9) conditions. For children 1 through 9, the highest differential risk was seen for other perinatal conditions (39.0), other endocrine (29.7), other CNS (24.5), and heart (21.4). CONCLUSIONS: Childhood mortality analyses that incorporate birth defects registry data provide a more comprehensive picture of the full burden of birth defects on mortality in infant and children and can provide an effective mechanism for monitoring the survival and mortality risks of children with selected birth defects on a population basis.     

Life history of yellow baboons: Physical development,reproductive parameters,and infant mortality

Longitudinal data from a population of yellow baboons,Papio cynocephalus, in the Amboseli National Park, Kenya, provide life history parameter estimates. Females reached menarche at approximately four-and-a-half years of age and then cycled for approximately a year before first conception. Postpartum anestrum averaged 12 months but ranged from six to 16 months. In cases of still births or infant death during postpartum amenorrhea, females commenced cycling after approximately one month. In mature females the time spent cycling before conception was five months on the average with a range from one to over 18 months. Only half of all full-term pregnancies resulted in infants who survived the first year of life; only a third, in infants who survived until the birth of their mother’s next infant. In comparison with data from laboratory colonies, our data indicate that female baboons in Amboseli are older at birth of first infant. They have, on the average, a somewhat shorter interbirth interval than was estimated from earlier crossectional field data, and therefore spend a larger portion of their adult life pregnant, but have a much longer interval—at least three years on the average—between the birth of an infant and the birth of that infant’s next older surviving sibling. A number of morphological changes in immature baboons are described.     

Mortality from Congenital Heart Disease in Mexico: A Problem on the Rise

Background and Objectives

Temporal trends in mortality from congenital heart disease (CHD) vary among regions. It is therefore necessary to study this problem in each country. In Mexico, congenital anomalies were responsible for 24% of infant mortality in 2013 and CHD represented 55% of total deaths from congenital anomalies among children under 1 year of age. The objectives of this study were to analyze the trends in infant mortality from CHD in Mexico (1998 to 2013), its specific causes, age at death and associated socio-demographic factors.

Methods

Population-based study which calculated the compounded annual growth rate of death rom CHD between 1998 and 2013. Specific causes, age at which death from CHD occurred and risk factors associated with mortality were analyzed for the year 2013.

Results

Infant mortality from CHD increased 24.8% from 1998 to 2013 (114.4 to 146.4/ 100,000 live births). A total of 3,593 CHD deaths occurred in 2013; the main causes were CHD with left-to-right shunt (n = 487; 19.8/100,000 live births) and cyanotic heart disease (n = 410; 16.7/100,000). A total of 1,049 (29.2%) deaths from CHD occurred during the first week of life. Risk factors associated with mortality from CHD were, in order of magnitude: non-institutional birth, rural area, birth in a public hospital and male sex.

Conclusions

Mortality from CHD has increased in Mexico. The main causes were CHD with left-to-right shunt, which are not necessarily fatal if treated promptly. Populations vulnerable to death from CHD were identified. Approximately one-third of the CHD occurred during the first week of life. It is important to promote early diagnosis, especially for non-institutional births.     

Patterns of infant mortality caused by major congenital anomalies

BACKGROUND: We assessed the impact of recent advances in perinatal care on infant mortality due to congenital anomaly. METHODS: Analysis of trends in congenital anomaly-attributed infant mortality, using the 1981-1995 Statistics Canada's birth and death records, with a total of 2,878,826 live births, 21,883 infant deaths, and 6, 908 infant deaths due to congenital anomalies. RESULTS: Infant mortality due to major congenital anomaly decreased from 3.11 per 1, 000 live births in 1981 to 1.89 per 1,000 live births in 1995. Cause-specific infant mortality rates for anencephaly, spina bifida, other central nervous system anomalies, cardiovascular system anomalies, respiratory system anomalies, digestive system anomalies, certain musculoskeleton anomalies, urinary system anomalies, chromosomal anomalies, and multiple congenital anomalies were 0.20, 0.23, 0.27, 1.04, 0.24, 0.08, 0.22, 0.16, 0.22, and 0.13 per 1,000 live births, respectively, in 1981-1983, whereas corresponding rates were 0.07, 0.07, 0.18, 0.73, 0.25, 0.03, 0.12, 0.12, 0.26, and 0.06 per 1,000 live births, respectively, in 1993-1995. CONCLUSIONS: Recent Canadian data show that infant deaths caused by major congenital anomalies have decreased significantly, but reductions varied substantially according to specific forms of anomalies.     

Deaths from cerebrovascular diseases correlated to month of birth: elevated risk of death from subarachnoid hemorrhage among summer-born

It has been suggested that maternal nutrition, and fetal and infant growth have an important effect on the risk of cardiovascular disease in adult life. We investigated the population-based distribution of deaths from cerebrovascular diseases (ICD9 codes 430, 431, or 434) in Japan in 1986–1994 as a function of birth month, by examining death-certificate records. For a total of 853 981 people born in the years 1900–1959, the distribution of the number of deaths according to the month of birth was compared with the distribution expected from the monthly numbers of all births for each sex and for the corresponding birth decade. For those born between 1920 and 1949, there were significant discrepancies between the actual numbers of deaths from subarachnoid hemorrhage (ICD9 430) and the numbers expected, and these differences were related to the month of birth. Those born in summer, June–September, consistently had an elevated risk of death, particularly men, where the excess risk was 8%–23%. This tendency was also observed, less distinctly but significantly, for deaths from intracerebral hemorrhage (ICD9 431), but was not observed for those dying from occlusion of the cerebral arteries (ICD9 434). The observation that the risk of dying from subarachnoid hemorrhage was more than 10% higher among those born in the summer implies that at least one in ten deaths from subarachnoid hemorrhage has its origin at a perinatal stage. Although variations in hypertension in later life, which could possibly be ”programmed” during the intra-uterine stages, could be an explanation for this observation, the disease-specific nature of the observation suggests the involvement of aneurysm formation, which is a predominant cause of subarachnoid hemorrhage. Received: 22 October 1999 / Revised: 8 May 2000 / Accepted: 10 May 2000     

Collaborative survey of perinatal loss in planned and unplanned home births. Northern Region Perinatal Mortality Survey Coordinating Group.

OBJECTIVE: To document the outcome of planned and unplanned births outside hospital. DESIGN: Confidential review of every pregnancy ending in stillbirth or neonatal death in which plans had been made for home delivery, irrespective of where delivery eventually occurred. The review was part of a sustained collaborative survey of all perinatal deaths. SETTING: Northern Regional Health Authority area. SUBJECTS: All 558,691 registered births to women normally resident in the former Northern Regional Health Authority area during 1981-94. MAIN OUTCOME MEASURE: Perinatal death. RESULTS: The estimated perinatal mortality during 1981-94 among women booked for a home birth was 14 deaths in 2888 births. This was less than half that among all women in the region. Only three of the 14 women delivered outside hospital. Independent review suggested that two of the 14 deaths might have been averted by different management. Both births occurred in hospital, and in only one was management before admission of the mother judged inappropriate. Perinatal loss to the 64 women who booked for hospital delivery but delivered outside and to the 67 women who delivered outside hospital without ever making arrangements to receive professional care during labour accounted for the high perinatal mortality (134 deaths in 3466 deliveries) among all births outside hospital. CONCLUSIONS: The perinatal hazard associated with planned home birth in the few women who exercised this option (< 1%) was low and mostly unavoidable. Health authorities purchasing maternity care need to address the much greater hazard associated with unplanned delivery outside hospital.     

Factors associated with unfavourable birth outcomes in Kenya

Studies addressing factors associated with adverse birth outcomes have almost exclusively been based on hospital statistics. This is a serious limitation in developing countries where the majority of births do not occur within health facilities. This paper examines factors associated with premature deliveries, small baby's size at birth and Caesarean section deliveries in Kenya based on the 1993 Kenya Demographic and Health Survey data. Due to the hierarchical nature of the data, the analysis uses multilevel logistic regression models to take into account the family and community effects. The results show that the odds of unfavourable birth outcomes are significantly higher for first births than for higher order births. Furthermore, antenatal care (measured by frequency of antenatal care visits and tetanus toxoid injection) is observed to have a negative association with the incidence of premature births. For the baby's size at birth, maternal nutritional status is observed to be a predominant factor. Short maternal stature is confirmed as a significant risk factor for Caesarean section deliveries. The observed higher odds of Caesarean section deliveries among women from households of high socioeconomic status are attributed to the expected association between socioeconomic status and the use of appropriate maternal health care services. The odds of unfavourable birth outcomes vary significantly between women. In addition, the odds of Caesarean section deliveries vary between districts, after taking into account the individual-level characteristics of the woman.     

Effects of the fertility transition on birth seasonality in the Netherlands

Synchronous with the decline in fertility that took place in the post-war period in the Netherlands, patterns of birth seasonality changed as well. In this paper seasonal fluctuations in fertility in the Netherlands are examined using population register data for the period 1952 to 2005. The peak in births has changed from spring to summer and subsequently to August/September, thereby shifting from the European to the American pattern. The seasonal shift can be attributed to parity-specific changes. Before the transition, birth seasonality did not differ much between the different parities. In the transition period from higher to low fertility, differences between parities increased which persist up to today. At present, the overall seasonality pattern is determined by first births. Moreover, birth seasonality varies by maternal age. The findings stimulate the discussion on the role of planning as a cause of birth seasonality.     

Maternal and Antenatal Risk Factors for Stillbirths and Neonatal Mortality in Rural Bangladesh: A Case-Control Study

Objective

To identify maternal and antenatal factors associated with stillbirths and neonatal deaths in rural Bangladesh.

Study Design

A prospective cohort study is being conducted to evaluate a maternal and child nutrition program in rural Bangladesh. Cases were all stillbirths and neonatal deaths that occurred in the cohort between March 7, 2011 and December 30, 2011. Verbal autopsies were used to determine cause of death. For each case, four controls were randomly selected from cohort members alive at age 3-months. Multivariable logistic regression was used to identify factors associated with these deaths.

Results

Overall, 112 adverse pregnancy outcomes (44 stillbirths, 19/1,000 births; 68 neonatal deaths, 29/1,000 live births) were reported. Of the stillbirths 25 (56.8%) were fresh. The main causes of neonatal death were birth asphyxia (35%), sepsis (28%) and preterm birth (19%). History of bleeding during pregnancy was the strongest risk factor for stillbirths (adjusted odds ratio 22.4 [95% confidence interval 2.5, 197.5]) and neonatal deaths (adjusted odds ratio 19.6 [95% confidence interval 2.1, 178.8]). Adequate maternal nutrition was associated with decreased risk of neonatal death (adjusted odds ratio 0.4 [95% confidence interval 0.2, 0.8]).

Conclusions

Identifying high-risk pregnancies during gestation and ensuring adequate antenatal and obstetric care needs to be a priority for any community-based maternal and child health program in similar settings.     

Change in social status and risk of low birth weight in Denmark: population based cohort study.

OBJECTIVE: To estimate the risk of having a low birthweight infant associated with changes in social, environmental, and genetic factors. DESIGN: Population based, historical cohort study using the Danish medical birth registry and Statistic Denmark''s fertility database. SUBJECTS: All women who had a low birthweight infant (< 2500 g) (index birth) and a subsequent liveborn infant (outcome birth) in Denmark between 1980 and 1992 (exposed cohort, n = 11,069) and a random sample of the population who gave birth to an infant weighing > or = 2500 g and to a subsequent liveborn infant (unexposed cohort, n = 10,211). MAIN OUTCOME MEASURES: Risk of having a low birthweight infant in the outcome birth as a function of changes in male partner, area of residence, type of job, and social status between the two births. RESULTS: Women in the exposed cohort showed a high risk (18.5%) of having a subsequent low birthweight infant while women in the unexposed cohort had a risk of 2.8%. After adjustment for initial social status, a decline in social status increased the absolute risk of having a low birthweight infant by about 5% in both cohorts, though this was significant only in the unexposed cohort. Change of male partner did not modify the risk of low birth weight in either cohort. CONCLUSION: Having had a low birthweight infant and a decline in social status are strong risk factors for having a low birthweight infant subsequently.     

Biological influence of infant death on fertility

This study examines the biological influence of infant death on subsequent fertility in three Asian countries--Indonesia, Nepal and Sri Lanka, comparing the birth interval between two consecutive births up to the sixth birth by survival status of the preceding infant among breast-feeding women not using contraception. There is consistent evidence of biological influence in each of the three countries. Infant death shortens birth intervals by up to 30%, though its influence varies between the countries.     

Season of birth affects short- and long-term survival

Recent research findings have highlighted the importance of early life conditions as risk factors for adult diseases and therefore determinants of subsequent survival. Given that individuals born during different seasons in seasonal environments experience different early-developmental conditions, an analysis of the effects of the season of birth on survival is considered an effective approach in clarifying the influence of early life conditions on survival in later life. In the present study, we analyzed the long-term effects of early developmental conditions in a historical population in which both nutritional levels and the burden of infectious diseases showed a seasonal variation. Using a semi-computerized linkage process, we were able to match birth and death data for 4,646 individuals born between 1634 and 1870 in the village of Es Mercadal (Minorca Island, Spain). To determine ecological differences associated with the season of birth, we first evaluated the association between season of birth and early life survival. This analysis helped us to determine seasonal variations in early life conditions such as infectious burden and nutritional levels. The season of birth had a significant effect on long-term survival in the birth cohort 1800-1870: summer births had a lower risk of death after age 15. We explain these results in terms of lower susceptibility to degenerative diseases in adult years due to superior in utero nutrition for summer births. These findings support the fetal origin hypothesis which states that the early life environment plays a key role in shaping the subsequent phenotype and risk of adult disease.