Increased risk of adverse maternal and infant outcomes among women with renal disease

We conducted a retrospective population-based study to estimate the risk of adverse maternal and neonatal outcomes in women with a diagnosis of renal disease during pregnancy. One hundred and sixty-nine women with renal disease who gave birth to a singleton infant between 1987 and 1993 were identified through linked Washington State hospital discharge and birth certificate databases. For comparison, 506 women without renal disease matched for year of delivery were selected. Women with renal disease were at increased risk of pre-eclampsia [OR = 7.2, 95% CI 4.2–12.5], preterm labour [OR = 7.9, 95% CI 1.9–32.6], dysfunctional labour [OR = 3.6, 95% CI 1.1–11.5], and caesarean section [OR = 3.1, 95% CI 2.0–4.8]. They were also at increased risk of delivering infants who were small for gestational age [OR = 5.3, 95% CI 2.8–10.0], preterm [OR = 6.1, 95%CI 3.3–11.3], and had 5-minute Apgar scores of less than 7 [OR = 3.9, 95% CI 1.1–14.6]. These associations persisted in analyses restricted to women without chronic hypertension. Women with renal disease and their infants also had median hospital charges that were more than twice those of women without renal disease and were more likely to be hospitalised longer. These data demonstrate that, independent of chronic hypertension, women with underlying renal disease are at increased risk of adverse maternal and perinatal outcomes and use more resources than women without renal disease.     

Maternal factors and breast cancer risk among young women

The results from previous studies have provided evidence to support the hypothesised association between intrauterine oestrogen exposure and subsequent risk of breast cancer. Information has not been available to study this relationship for several perinatal factors thought to be related to pregnancy oestrogen levels. Data collected from the mothers of women in two population-based case–control studies of breast cancer in women under the age of 45 years (510 case mothers, 436 control mothers) who were diagnosed between 1983 and 1992 in three western Washington counties were used to investigate further the relationship between intrauterine oestrogen exposure and risk of breast cancer. A pregnancy weight gain of 25–34 pounds was associated with breast cancer risk (odds ratio [OR] = 1.5; 95% confidence interval [CI] 1.1, 2.0); however, women whose mothers gained 35 pounds or more were not at increased risk. Use of antiemetic medication in women with any nausea and vomiting (OR = 2.9; 95% CI 1.1, 8.1) and use of diethylstilboestrol (DES) (OR = 2.3; 95% CI 0.8, 6.4) appeared to be positively associated with breast cancer risk. The results from this study provide limited support for the hypothesis that in utero oestrogen exposure may be related to subsequent breast cancer risk among young women.     

Disparities in Fetal Death and First Day Death: The Influence of Risk Factors in 2 Time Periods

Objectives. We examined how changes in risk factors over time influence fetal, first day, and combined fetal–first day mortality and subsequent racial/ethnic disparities.Methods. We selected deliveries to US resident non-Hispanic White and Black mothers from the linked live birth–infant death cohort and fetal deaths files (1995–1996; 2001–2002) and calculated changes over time of mortality rates, odds, and relative odds ratios (RORs) overall and among mothers with modifiable risk factors (smoking, diabetes, or hypertensive disorders).Results. Adjusted odds ratios (AORs) for fetal mortality overall (AOR = 0.99; 95% confidence interval [CI] = 0.96, 1.01) and among Blacks (AOR = 0.98; 95% CI = 0.93, 1.03) indicated no change over time. Among women with modifiable risk factors, the RORs indicated no change in disparities. The ROR was not significant for fetal mortality (ROR = 0.96; 95% CI = 0.83, 1.01) among smokers, but there was evidence of some decline. There was evidence of increase in RORs in fetal death among mothers with diabetes and hypertensive disorders, but differences were not significant.Conclusions. Disparities in fetal, first day, and combined fetal–first day mortality have persisted and reflect discrepancies in care provision or other factors more challenging to measure.Stillbirths (or fetal deaths) have recently received international attention as an unrecognized public health issue.1 Although much of the focus has been on developing countries, fetal deaths continue to be a concern in developed nations. In the United States, there have been improvements in perinatal (fetal plus infant) mortality over the past few decades, with a 56% decline overall from 1970 (14.0 per 1000 live births plus fetal deaths) to 2005 (6.2 per 1000 live births plus fetal deaths).2 However, substantial disparities remain and in some cases continue to grow.3–7 The 2-fold disparities between non-Hispanic Blacks (Blacks) and non-Hispanic Whites (Whites) persist as demonstrated by several studies examining the racial and ethnic disparities in perinatal mortality.4–9 The primary reason for this widening gap is in part attributable to larger declines in infant and fetal mortality among Whites compared with Blacks.Although many studies have considered temporal changes in perinatal death5,10 and other studies have considered the influence of selected maternal characteristics and risk factors on adverse birth outcomes,5,6,8,11 few studies have simultaneously examined these temporal changes in fetal and early infant death in the context of maternal characteristics and risk factors.Our purpose was to examine how temporal changes in maternal, sociodemographic, and medical risk factors influence the changes in fetal, first day, and combined fetal–first day (fetal plus first day death) mortality. We explored racial and ethnic variations and disparities for selected modifiable maternal characteristics and risk factors as related to mortality outcomes, possibly providing some insight into systematic disparities in perinatal health and clinical management. If differences in perinatal or fetal mortality exist between racial and ethnic groups with these potentially modifiable characteristics or behaviors, it is possible that there may be differentials in access to health care or provision of care. We chose to examine first day deaths in combination with fetal deaths because an artificial reduction in fetal deaths may account for a rise in infant deaths. Events once classified as fetal deaths may now be classified as first day deaths reflecting misclassification of the timing of death; changes in management of the delivery of very small, very early fetuses; or overall changes in baseline health.     

Early obstetric discharge: does it make a difference to health outcomes?

Summary.   Clinicians in several countries have expressed concerns about possible adverse effects of shortening obstetric length of stay. A population-based survey of 1366 mothers who gave birth in Victoria, Australia, in 1993 was used to investigate social and obstetric characteristics of mothers discharged home 'early', and to assess whether shorter stays were associated with adverse health outcomes, or a lesser degree of satisfaction, or both. Women's views and experiences of length of hospital stay were gathered via a statewide postal survey of women who gave birth in a 2-week period; 62.5% ( n  = 1336) responded. Assessment of the relationship between length of stay (1–2 days vs. 5 days, and 3–4 days vs. 5 days) and four main outcome measures (infant feeding at 6 weeks, period prevalence of feeding problems, maternal confidence and depression) showed no association between these variables and length of stay after adjusting for other obstetric and social factors in separate regression analyses. For stays of 3–4 days, the adjusted odds ratio (OR) for formula feeding at 6 weeks was 1.35 [95% confidence interval (CI) 0.9–1.9]; for feeding problems OR = 0.87 [0.7–1.2]; for lacking confidence OR = 0.81 [0.6–1.2]; and for depression OR = 0.96 [0.7–1.4]. Large randomised trials of early obstetric discharge are required to resolve continuing uncertainties about the safety, and possible benefits of shorter hospital stays.     

Smoking during pregnancy and babbling abilities of the 8-month-old infant

Summary.   Animal experiments suggest that the fetal brain is sensitive to nicotine. Although much attention has been given to the relation between cigarette smoking during pregnancy and neurodevelopment in children, this remains controversial. Our study describes the relationship between maternal cigarette smoking during pregnancy and babbling abilities of the 8-month-old infant. In a longitudinal cohort, information was collected at the 16th week of gestation, at delivery and when the infant was about 8 months old. At this age babbling abilities of the infant were evaluated by a health visitor during a home visit. Singleton infants without any disability born at Aarhus University Hospital, Denmark, 1991–92 and still living in the Community of Aarhus at the age of 8 months were eligible ( n  = 2302). Complete follow-up was obtained for 1871 children (81.3%). A dose–response-like relationship between number of cigarettes smoked per day during pregnancy and babbling abilities was found after controlling for potential confounders. Smoking 10 or more cigarettes per day during pregnancy almost doubled the risk (odds ratio [OR] = 2.0, 95% confidence interval [CI] 1.1–3.6) of the infant being a non-babbler at the examination at 8 months. Among children who were breast fed for less than 4 months this risk was even higher (OR = 2.7, CI 1.3–5.8).     

Intergenerational influences affecting birth outcome. II. Preterm delivery and gestational age in the children of the 1958 British birth cohort

The 1958 British cohort study has data to investigate intergenerational effects on preterm delivery and on gestational age in non-preterm births, allowing for many confounders that may differ in the more pathological preterm babies. Previous results for all gestational ages have been inconsistent. The strongest and only likely independent intergenerational effect on non-preterm gestational age found is parental gestational age (adjusted regression coefficient = 0.067 weeks per week in mothers and 0.045 in fathers). The preterm analysis has low power; however, reported history of hypertension in mothers (any), in fathers and in the maternal grandmother (measured in the 1958 pregnancy) all significantly and independently increased the risk of preterm birth [OR = 1.7, 2.0, 1.5 respectively]. The absolute risk was particularly high in hypertensive mothers who had been preterm themselves (21%). Other possible intergenerational influences of height, weight, fetal growth and gestation were not significant enough and/or consistent enough between parents to speculate whether they are truly intergenerational or confounded by other factors acting during the pregnancy. Excepting mother's weight for height, no genetic or environmental influence studied affects both gestational age and fetal growth in term births. However, many maternal factors that reduce either fetal growth or gestation in term births are associated with increased risk of preterm birth.     

未足月胎膜早破期待治疗妊娠结局的多因素分析

目的:探讨未足月胎膜早破(PPROM)期待治疗中母儿不良妊娠结局的独立危险因素。方法:回顾性分析132例PPROM孕妇的临床资料,按照有无孕妇及新生儿严重并发症(包括新生儿死亡)的发生分别分为孕妇不良妊娠结局组与对照组和新生儿不良结局组与对照组,分别比较两组患者的一般临床情况及各项检验指标。采用多因素Logistic回归分析母儿不良妊娠结局的危险因素。结果:132例期待治疗中,34例孕妇出现严重并发症,发生率为25.8%(34/132),无孕产妇死亡。胎死宫内4例,47例新生儿出现明显并发症,其中8例新生儿死亡,围产儿死亡率为5.8%(8/138)。经多因素回归分析,就诊时间(以2h为界)及感染是孕妇严重并发症发生的独立危险因素,分娩孕周、就诊时间及感染是新生儿病率及死亡率的独立危险因素。结论:PPROM期待治疗过程需严密监测及预防感染,孕周小者适当延长孕周;在2h内就诊,预防性使用抗生素及促胎肺成熟,可减少孕产妇感染及围生儿病死率。     

Racial and ethnic differences in perinatal mortality: the role of fetal death

PURPOSE: We investigate whether variations in infant mortality rates among racial/ethnic groups could be explained by variations in fetal mortality rates where relatively higher infant mortality rates may correspond to lower fetal mortality rates due to possible systematic differences in reporting of fetal death compared to live births. METHODS: Using US perinatal data from 1995 to 1999, we calculated crude mortality rates, birth weight-specific fetal and hebdomadal mortality rates, risks of perinatal death, and the risk of being classified as a fetal death versus other period death among infants born to Non-Hispanic White, Non-Hispanic Black, and Hispanic mothers. RESULTS: Two-fold disparities between Whites and Blacks persist for all mortality categories. Black low birth-weight deliveries, compared to Whites, have perinatal advantages in both fetal and hebdomadal periods. Hispanics were less likely than Whites to be reported as a fetal versus a hebdomadal death. CONCLUSIONS: While these data suggest some underreporting of Black fetal deaths, they provide little evidence that Black-White disparities in infant mortality are a function of variations in classifying a death occurring at delivery as either a fetal death or as a live birth-infant death. These data suggest that the lack of a White-Hispanic disparity in fetal mortality rates may be influenced by underreporting.     

Risk factors for perinatal deaths in rural Bangladesh

Perinatal mortality refers to stillbirths and deaths which occur during the first week of life. 7 million such deaths occur annually worldwide, almost all of which are in developing countries. Rates as high as 75-100 deaths/1000 births have been documented in developing countries. The 3 leading causes of perinatal mortality are complications of pre-term birth, birth asphyxia and birth trauma, and bacterial infections. The other causes of perinatal mortality are largely unknown due to difficulties in documenting stillbirths in developing countries. In many developing country societies, it is culturally unacceptable to acknowledge a birth until it has survived its first week of life. This study identified and quantified the risk factors for perinatal deaths in a rural community in Manikganj district, Bangladesh. Cases were mothers whose infants died in the perinatal period, while comparison mothers were those whose infants survived the perinatal period. Of the 186 infant deaths recorded, 130 (69.9%) were in the perinatal period, and included 53 stillbirths. The perinatal death rate was 64.5/1000 births. Logistic regression confirmed that maternal age, parity, and mal-presentation were significantly associated with perinatal deaths. Mal-presentation was independently associated with a increased risk of perinatal death.     

Perinatal mortality in Shanghai: 1986-1987.

The incidence of, and risk factors associated with, perinatal mortality in Shanghai during 1986-1987 are examined using data from a multi-site study conducted in 29 hospitals. The overall perinatal mortality rate was 14.96 per 1000 births. The mortality rates of antepartum fetal death, intrapartum fetal death and early neonatal death were 5.97, 2.06 and 6.94 per 1000 births, respectively. The perinatal mortality rates increased in winter and late spring. Male neonates were 1.5 times more likely to die than females. Low birthweight and preterm infants had 15 to 80 times higher risk of perinatal death. Higher parity, multiple pregnancy, and maternal age greater than or equal to 35 years were the risk factors for perinatal mortality. Asphyxia, cord complications, and congenital malformations were found to be the major causes of perinatal deaths. Comparison of mortality rates between Shanghai and the US suggests that the shortage of advanced technology in perinatal care (e.g. neonatal intensive care units) is a major obstacle to the reduction of perinatal mortality in Shanghai.     

Infant mortality in Norway and Sweden 1975–88: a cause-specific analysis of an increasing difference

In a previous article, a high infant mortality was reported in the 1980s in Norway compared with Sweden. The aim of the present study was to assess secular trends in this difference, and to clarify whether the difference was confined to particular causes of death. Mortality rates, ratios of mortality rates and numbers of excess deaths were calculated on the basis of birth records comprising all livebirths in Norway and Sweden during the two periods 1975–79 and 1985–88. From the first to the second period, the infant mortality ratio for Norway to Sweden increased from 1.22 to 1.45 for single births, and from 1.23 to 1.54 for twin births. Increasing mortality ratios were observed for all ages at death. These were lowest in the early neonatal period (1.09 and 1.20 respectively) and highest in the postneonatal period (1.53 and 1.78 respectively). Within each cause of death category, the mortality rate in Norway was equal to or higher than the rate in Sweden. The highest mortality rate ratios were observed for sudden infant death syndrome (SIDS), 2.44 and 2.46 respectively, for the two time periods. SIDS was also the single cause of death that gave the largest contribution to the Norwegian excess mortality (45% and 53% overall, 65% and 78% for postneonatal deaths, and 65% and 79% for birthweights above 2500 g). In the second period, the excess SIDS mortality in Norway pertained mainly to infants of young mothers, infants of birth order two or more and twin births. An adverse trend for infants of young mothers in Norway was also observed in non-SIDS deaths. This suggests that in Norway, preventive health care should be improved, particularly for young mothers and their infants.     

Trend in cerebral palsy birth prevalence in eastern Denmark: birth-year period 1979–86

To investigate changes in cerebral palsy birth prevalence and perinatal mortality rate by different gestational age groups, 1979–86, cerebral palsy cases in eastern Denmark were identified from the Danish Cerebral Palsy Register, and information on birth and mortality rates was sought in the Danish Medical Birth Register. From 1979–82 to 1983–86, the birth prevalence of cerebral palsy increased from 2.6 to 3.0 per 1000 ( P  < 0.05). The rate for infants of 31 weeks' gestation or more did not change, whereas a significant increase was observed in infants below 31 weeks (85–123 per 1000, P  < 0.05). In the same periods, perinatal mortality in eastern Denmark decreased significantly from 8.6 to 7.8 per 1000. The decrease in stillbirth rate was significant in all subgroups of gestational ages except in those of 28–30 weeks' gestation. The early neonatal mortality rate decreased significantly only in infants below 31 weeks (282–239 per 1000, P  < 0.05). Thus, in eastern Denmark, cerebral palsy birth prevalence has increased from birth-year period 1979–82 to 1983–86 because of an increased rate in preterm infants below 31 weeks, who at the same time had a reduced risk of early neonatal death.     

Trends in the Mexican infant mortality paradox over the past two decades

PurposeMexicans in the United States have lower rates of several important population health metrics than non-Hispanic whites, including infant mortality. This mortality advantage is particularly pronounced among infants born to foreign-born Mexican mothers. However, the literature to date has been relegated to point-in-time studies that preclude a dynamic understanding of ethnic and nativity differences in infant mortality among Mexicans and non-Hispanic whites.MethodsWe assessed secular trends in the relation between Mexican ethnicity, maternal nativity, and infant mortality between 1989 and 2006 using a linked birth–death data set from one US state.ResultsCongruent to previous research, we found a significant mortality advantage among infants of Mexican relative to non-Hispanic white mothers between 1989 and 1991 after adjustment for baseline demographic differences (relative risk = 0.78, 95% confidence interval, 0.62–0.98). However, because of an upward trend in infant mortality among infants of Mexican mothers, the risk of infant mortality was not significantly different from non-Hispanic white mothers in later periods.ConclusionsOur findings suggest that the “Mexican paradox” with respect to infant mortality is resolving. Changing sociocultural norms among Mexican mothers and changes in immigrant selection and immigration processes may explain these observations, suggesting directions for future research.     

A Secondary Analysis of Race/Ethnicity and other Maternal Factors Affecting Adverse Birth Outcomes in San Bernardino County

Objectives Though it is the largest county in the lower United States, minimal attention has been given to the elevated rates of poor perinatal outcomes and infant mortality in San Bernardino County. This study sought to analyze adverse birth outcomes such as low birth weight, and infant mortality as an outcome of specific proxy maternal sociodemographic factors. Methods Data from the California Department of Health Services Office of Vital Statistics birth cohort of mothers delivering between 1999 and 2001 (N = 1,590,876 participants) were analyzed. Of those, 5.5% (n = 86,736) were births in San Bernardino County. Low birth weight, very low birth weight, death in infants less than one year of age, and other maternal sociodemographic factors were explored. All events of low birth weight and deaths among infants less than one year of age were used as significant variables in statistical models. Results Black mothers experienced more than twice the rate of very low birth weight (3.89) than their White counterparts (1.39). The most significant contributors to adverse birth outcomes among Black women were length of gestation and maternal education, whereas the most significant predictor of infant mortality was birth weight. Conclusions This study demonstrates that traditional risk factors such as length of gestation and maternal age only partially explain adverse birth outcomes. These findings highlight the need to advocate for the systematic collection of data on maternal education and length gestation and for the promotion of public health initiatives that address these inequities in our most vulnerable of populations.     

The impact of maternal health improvement on perinatal survival: cost-effective alternatives

Each year, an estimated half million women die from complications related to child birth either during pregnancy, delivery or within 42 days afterwards. When pregnant women have complications, their infants are at greater risk of becoming ill, permanently disabled or dying. For every maternal death, there are at least 20 infant deaths: stillbirths, neonatal or postneonatal deaths. Altogether, an estimated 7 million infants each year die perinatally (stillborn or deaths within the first week of life). Low cost, feasible, and effective intervention strategies include: a) improved family planning and abortion services; b) obstetric care at delivery; and, c) prenatal services. Two hypothetical populations of one million (a low mortality and a high mortality country) are used to illustrate maternal and perinatal program strategies and priorities. In countries with high fertility, major reductions in maternal and infant deaths result both from reductions in the number of pregnancies through family planning and from improved obstetric care. Where fertility is already low, reductions result almost entirely from improved obstetric and prenatal care. The investments required are relatively low, while the potential gains are great. The cost to avert each death in a high mortality population is estimated between $800 and $1,500 or as low as $0.50 per capita per year. The priorities for programs targeting maternal and perinatal health depend on demographic, ecologic and economic factors, and should include the promotion of good health, not merely the avoidance of death. More operational research is required on various aspects of maternal and perinatal health; in particular, on the cost-effectiveness of different service components.     

No fathers' names: a risk factor for infant mortality in the State of Georgia, USA

Many studies have explored maternal and infant factors as risks for infant mortality, but little attention is given to paternal factors. In Georgia, listing a father's name on the birth certificate is optional for married couples and possible after paternal acknowledgment for unmarried couples. The authors evaluated father's name reporting as a paternity measure and risk for infant mortality. Using the linked 1989-1990 birth and death certificates of singleton Georgia infants to calculate relative risks (RRs), infant mortality rates for 38,943 infants with no father's names listed were compared to rates for 178,100 with father's names listed. Compared with the rate for married women listing names, the death rates were higher for unmarried mothers not listing fathers (relative risk, RR = 2.5; 95% CI 2.3-2.7), unmarried mothers listing fathers (RR = 1.4; 95% CI 1.3-1.6), and married women not listing fathers (RR = 2.3; 95% CI 1.6-3.1). Increased risks remained after stratifying by maternal race, age, adequacy of prenatal care and medical risks; and congenital malformations, birthweight, gestational age, and small-for-gestational age. Using logistic regression to examine for effect modification and to adjust for these factors together, the adjusted relative risks for death varied across different groups without fathers' names, regardless of marital status. For example, it remained statistically higher for infants with no father listed and without effect-modifying conditions such as low birthweight (estimated RR = 2.0; 95% CI 1.6-2.4). Although these findings suggest paternal involvement, as measured by listing fathers' names, is protective against low birthweight and infant mortality, further evaluation is needed.     

Assessing Maternal Risk for Fetal-Infant Mortality: A Population-Based Study to Prioritize Risk Reduction in a Healthy Start Community

Study goals were to distinguish between maternal risk factors for fetal versus infant mortality, and to identify which maternal characteristics contributed the greatest risk of mortality overall. This case–control retrospective study abstracted data on more than forty maternal characteristics from 261 prenatal and delivery records: all 26 fetal deaths, all 40 infant deaths and 195 randomly selected surviving births in a high-mortality Healthy Start community. Bivariate and multivariate analyses were conducted. The fetal-mortality population was significantly more likely than the infant-mortality population to have no insurance (P = .047), inadequate prenatal care (P = .039) and previous fetal death (P = .021). Comparing the combined mortality population with the surviving sample, two tiers of risk emerged: Rare-but-lethal risks, including no prenatal care (P < .001) and Child-Protective-Service involvement (P = .001), and common-and-dangerous risks, including inadequate maternal weight gain (OR = 13.55), drug or alcohol abuse (OR = 8.67), obesity (OR = 2.77) and anemia (OR = 3.61). Both fetal and infant mortality groups must be considered when identifying maternal risks. Inadequate prenatal weight gain, obesity and anemia contribute as much to feto-infant mortality as substance abuse. Public health efforts to improve maternal nutrition and healthy weight should be redoubled.     

Supplemental analyses of recent trends in infant mortality.

U.S. preliminary data for 2002 show a significant increase in the infant mortality rate to 7.0 infant deaths per 1,000 live births, the first rise in the infant mortality rate since 1958. The increase in infant mortality was concentrated in the neonatal period, particularly in deaths occurring within seven days of birth. Partially edited fetal death data suggest that the increase in neonatal mortality was accompanied by a decline in the late fetal mortality rate, and thus it appears that the 2002 perinatal mortality rate will remain level. Potential explanatory factors for the changes in the infant mortality rate are examined, including causes of infant death, percentage of births that are preterm, and low birthweight. Data from the 2002 linked birth and infant death file will allow an assessment of the contribution of maternal and infant factors such as multiple births and management of labor and delivery.     

Pregnancy Outcomes of American Indians: Contrasts Among Regions and with Other Ethnic Groups

Objectives The two-fold purpose of this analysis is first to contrast the maternal risk factors and birth outcomes of American Indians (AIs) with other race/ethnic groups and to compare the maternal risk factors and birth outcomes of AIs by region to assess whether there are geographic variations in the adverse outcomes that might suggest intervention strategies. Study Design This study used the National Center for Health Statistics live birth infant death cohort files from 1995–2001. Singleton live births to U.S. resident mothers were selected. The analyses were limited to non-Hispanic American Indians, including Aleuts and Eskimos (n = 239,494), Non-Hispanic White (n = 15,488,133), and Hispanic births (n = 5,284,978). Results This comparison of birth characteristics and outcomes by ethnic group revealed that AIs have more adverse maternal risk factors (e.g., unmarried and <18 years of age) than Whites and Hispanics. After adjustment for these factors, AIs have higher risks of low birth weight and preterm birth and elevated risks of postneonatal and infant mortality. Their cause-specific rates for perinatal, SIDS, injury and infection are also higher. The regional analysis indicated the South/Northeast have more low birth weight and preterm problems, but the Mid-West has the highest risks of infant mortality among LBW infants gestational age-specific mortality rates, and mortality from SIDS. Conclusions These data show that AIs are not a homogenous group as evinced by distinct regional differences. SIDS is mainly a problem in the Mid-West, suggesting the involvement of environmental factors in that region. Further investigation is needed to examine the current AI perinatal health concerns.