Epidemiology of fetal death in Latin America

BACKGROUND: To identify risk factors associated with fetal death, and to measure the rate and the risk of fetal death in a large cohort of Latin American women. METHODS: We analyzed 837,232 singleton births recorded in the Perinatal Information System Database of the Latin American Center for Perinatology and Human Development (CLAP) between 1985 and 1997. The risk factors analyzed included fetal factors and maternal sociodemographic, obstetric, and clinical characteristics. Adjusted relative risks were obtained, after adjustment for potential confounding factors, through multiple logistic regression models based on the method of generalized estimating equations. RESULTS: There were 14,713 fetal deaths (rate=17.6 per 1000 births). The fetal death risk increased exponentially as pregnancy advanced. Thirty-seven percent of all fetal deaths occurred at term, and 64% were antepartum. The main risk factors associated with fetal death were lack of antenatal care (adjusted relative risk [aRR]=4.26; 95% confidence interval, 3.84-4.71) and small for gestational age (aRR=3.26; 95% CI, 3.13-3.40). In addition, the risk of death during the intrapartum period was almost tenfold higher for fetuses in noncephalic presentations. Other risk factors associated with stillbirth were: third trimester bleeding, eclampsia, chronic hypertension, preeclampsia, syphilis, gestational diabetes mellitus, Rh isoimmunization, interpregnancy interval<6 months, parity > or =4, maternal age > or =35 years, illiteracy, premature rupture of membranes, body mass index > or =29.0, maternal anemia, previous abortion, and previous adverse perinatal outcomes. CONCLUSIONS: There are several preventable factors that should be dealt with in order to reduce the gap in fetal mortality between Latin America and developed countries.     

Determinants of intrapartum fetal death in a remote and indigent population in China.

OBJECTIVE: To explore the reasons for the high rate of intrapartum fetal death observed in a remote and indigent population in China. STUDY DESIGN: We conducted an epidemiologic analysis of determinants of intrapartum fetal death in a sample of 20,891 births in 18 hospitals participating in the Qingyuan Perinatal Surveillance System from January 1, 1997 to June 30, 1998. The main determinant examined was cesarean delivery; other determinants included mother's insurance status, residence, maternal age, infant's gender, parity, gestational age, birth weight, and obstetric complications. Rates of intrapartum fetal death within categories of various maternal and infant factors were first calculated and compared; adjusted odds ratios for intrapartum fetal death were then estimated by multiple logistic regression analysis. RESULTS: The intrapartum fetal death rate in this population was 5 per 1000 total births, which accounted for about one-third of all fetal deaths. Compared with vaginal delivery, elective cesarean delivery was associated with a 100% (i.e., no intrapartum fetal death among 1572 elective cesarean deliveries) and emergency cesarean delivery with a 88% reduction, in intrapartum fetal death. Other significant determinants were related to access to obstetric care (i.e., insurance status and residence). CONCLUSION: Lack of access to quality obstetric care is the major determinant of intrapartum fetal death in this population.     

The impact of prenatal care on fetal and neonatal death rates for uninsured patients: a "natural experiment" in West Virginia.

A three-county program in southern West Virginia was developed by an obstetric practice to deliver prenatal care to a population of uninsured patients. Between January 1984 and December 1986, 1331 (29.4%) of 4534 patients were delivered at a level 2 hospital after prenatal care within the clinic program. The hospital-wide fetal death ratio declined from 11.8 to 7.2 per 1000 live births during the years of clinic operation, a statistically significant reduction (P = .02). Uninsured patients experienced a statistically significant reduction in fetal death ratio during the program, from 35.4 to 7.0 per 1000 live births (P = .02), whereas those covered by medical assistance did not experience a reduction. Privately insured patients also had a significant decrease, from 10.0 to 3.1 per 1000 live births (P less than .001). The increasing operating expense, mainly due to rising malpractice insurance premiums, required suspension of the program in December 1986. The fetal death ratio returned to 10.3 deaths per 1000 live births in 1987. Factors that varied significantly during the "clinic" phase included: higher rates of cesarean, diagnosed maternal hypertension, and diabetes mellitus; and lower rates of premature rupture of membranes and non-white population. Other factors, including age over 35 years, postdatism, incidence of twins, incidence of lethal congenital anomalies, and single marital status, did not vary significantly before, during, or after the clinic program. This study identified a high-risk population of patients who did not qualify for medical assistance coverage and were de facto "uninsured." The results suggest that prenatal care for this high-risk population of uninsured patients can reduce the fetal death rate.     

Determinants of unexplained antepartum fetal deaths

OBJECTIVE: To assess fetal, maternal, and pregnancy-related determinants of unexplained antepartum fetal death. METHODS: We conducted a hospital-based cohort study of 84,294 births weighing 500 g or more from 1961-1974 and 1978-1996. Unexplained fetal deaths were defined as fetal deaths occurring before labor without evidence of significant fetal, maternal, or placental pathology. RESULTS: One hundred ninety-six unexplained antepartum fetal deaths accounted for 27.2% of 721 total fetal deaths. Two thirds of the unexplained fetal deaths occurred after 35 weeks' gestation. The following factors were independently associated with unexplained fetal death: maternal prepregnancy weight greater than 68 kg (adjusted odds ratio [OR] 2.9; 95% confidence interval [CI] 1.85, 4.68), birth weight ratio (defined as ratio of birth weight to mean weight for gestational age) between 0.75 and 0.85 (OR 2.77; 95% CI 1.48, 5.18) or over 1.15 (OR 2.36; 95% CI 1.26, 4.44), fewer than four antenatal visits in women whose fetuses died at 37 weeks or later (OR 2.21; 95% CI 1.08, 4.52), primiparity (OR 1.74; 95% CI 1.26, 2.40), parity of three or more (OR 2.01; 95% CI 1.26, 3.20), low socioeconomic status (OR 1.59; 95% CI 1.14, 2.22), cord loops (OR 1.75; 95% CI 1.04, 2.97) and, for the 1978-1996 period only, maternal age 40 years or more (OR 3.69; 95% CI 1.28, 10.58). Trimester of first antenatal visit, low maternal weight, postdate pregnancy, fetal-to-placental weight ratio, fetal sex, previous fetal death, previous abortion, cigarette smoking, and alcohol use were not significantly associated with unexplained fetal death. CONCLUSION: In this study, we identified several factors associated with an increased risk of unexplained fetal death.     

Trends in the cause of late fetal death, 1982-2000

BACKGROUND: Progress in reducing late fetal deaths has slowed in recent years, despite changes in intrapartum and antepartum care. OBJECTIVES: To describe recent trends in cause-specific fetal death rates. DESIGN: Retrospective cohort study. SETTING: North of England. POPULATION/SAMPLE: 3,386 late fetal deaths (> or = 28 weeks of gestation and at least 500 g), occuring between 1982 and 2000. METHODS: Data on deaths were obtained from the Northern Perinatal Mortality Survey. Data on live births were obtained from national birth registration statistics. Rate ratios (RR) and 95% confidence intervals (CI) for fetal deaths in 1991-2000 compared with 1982-1990 were calculated. MAIN OUTCOME MEASURES: Cause-specific late fetal death rates per 10,000 total births. RESULTS: Mortality in singletons declined from 51.5 per 10,000 births in 1982-1990 to 42.0 in 1991-2000 (RR 0.82, 95% CI 0.76-0.87). There was a greater decline in multiples, from 197.9 to 128.0 per 10,000 (RR 0.65, 95% CI 0.51-0.83). In singletons, the largest reductions occurred in intrapartum-related deaths, and deaths due to congenital anomalies, antepartum haemorrhage and pre-eclampsia. There was little change in the rate of unexplained antepartum death occurring at term (RR 0.97, 95% CI 0.84-1.11) or preterm (RR 0.94, 95% CI 0.82-1.07), these accounting for about half of all late fetal deaths. Unexplained antepartum deaths declined in multiple births and in singletons of birthweight < 1500 g. CONCLUSIONS: While late fetal mortality due to many specific causes has declined, unexplained antepartum death rates have remained largely unchanged. Improved identification of deaths due to growth restriction and infection, which may otherwise be classified as unexplained, is important. Further investigation of the underlying aetiologies of genuinely unexplained deaths is needed.     

Unexplained antepartum fetal deaths: what are the determinants?

Objective The objective was to assess fetal, antenatal, and pregnancy determinants of unexplained antepartum fetal death.Methods This is a hospital-based cohort study of 34,394 births weighing 500 g or more from January 1995 to December 2002. Unexplained fetal deaths were defined as fetal deaths occurring before labor, without evidence of significant fetal, maternal or placental pathology.Results Ninety-eight unexplained antepartum fetal deaths accounted for 27.2% of 360 total fetal deaths. Two-thirds of these deaths occurred after 36 weeks gestation. The following factors are independently associated with unexplained fetal deaths: primiparity (OR 1.74; 95% CI 1.21, 2.86); parity of five or more (OR 1.19; 95% CI 1.26, 3.26); low socioeconomic status (OR 1.22; 95% CI 1.14, 2.86); maternal age 40 years or more (OR 3.62; 95% CI 1.22, 4.52); maternal age of 18 years or less (OR 1.79; 95% CI 0.82, 2.89); maternal prepregnancy weight greater than 70 kg (OR 2.20; 95% CI 1.85, 3.68); fewer than three antenatal visits in women whose fetuses died at 31 weeks or more (OR 1.11; 95% CI 1.08, 2.48); birth weight ratio (defined as ratio of birth weight to mean birth weight for gestational age) between 0.85 and 0.94 (OR 1.77; 95% CI 1.28, 4.18) or over 1.45 (OR 2.92; 95% CI 1.75, 3.21); trimester of first antenatal visit. Previous fetal death, previous abortion, cigarette smoking, fetal sex, low maternal weight, fetal-to-placenta weight, and post date pregnancy were not significantly associated with unexplained fetal deaths.Conclusion Several factors were identified that are associated with an increased risk of unexplained fetal deaths.     

Fetal deaths in the United States, 1997 vs 1991

OBJECTIVE: The purpose of this study was to examine the temporal change in fetal death risk in the US from 1991 to 1997, and to assess the extent to which changes in registration practices and labor induction have contributed to that change. STUDY DESIGN: This was a cohort study of all singleton pregnancies 20 to 43 weeks of gestation in 1991 and 1997 in the US. RESULTS: From 1991 to 1997, the overall fetal death rate fell from 77.6 to 67.8 per 10,000 total births. However, fetal deaths at 20 to 22 weeks as a proportion of total births increased from 14.5 to 16.9 per 10,000. In a Cox regression analysis, the crude period effect (1997 vs 1991) at 40 to 43 weeks was 0.87 (95% CI 0.80-0.94), and remained virtually unchanged (HR 0.88, 95% CI 0.81-0.96) after adjustment for maternal sociodemographic, medical, and lifestyle risk factors. In ecologic (Poisson regression) analysis based on states as the unit of analysis, the crude period effect in non-Hispanic whites (RR 0.79, 95% CI 0.74-0.84) disappeared (RR 0.98, 95% CI 0.82-1.16) after adjusting for induction of labor. The effect of induction in blacks was limited to 42 to 43 weeks in those at high risk. CONCLUSION: Increased registration is probably responsible for an increase in fetal death risk at 20 to 22 weeks of gestation, whereas the increasing trend toward routine labor induction at and after term appears to have reduced the risk of fetal death, especially among whites.     

Ethnicity and birth outcome: New Zealand trends 1980-2001: Part 3. Pregnancy outcomes for Pacific women

BACKGROUND: Pacific women in New Zealand reside in areas of higher socioeconomic deprivation compared to women from other ethnic groups. Pacific women and their health are further disadvantaged because of genetic predisposition and sociocultural factors that cause ill-health. The correlations between pregnancy outcomes, risk factors and other health indices in Pacific women need evaluation. AIMS: To examine trends in preterm birth, small for gestational age (SGA) and late fetal death for Pacific women during 1980-2001 and to explore risk factors which make this group vulnerable to adverse birth outcome. METHODS: De-identified birth registration data from 1 189 120 singleton live births and 5775 stillbirths were analysed for 1980-2001. Outcomes of interest included preterm birth, SGA and late fetal death while explanatory variables included maternal ethnicity, age and NZ Deprivation Index decile. Trend analysis was undertaken for 1980-1994 and multivariate logistic regression was used to explore risk factors for 1996-2001. RESULTS: Pacific women had the lowest rates of preterm birth and SGA when compared to Maori and European women. In addition, preterm birth rates underwent a non-significant 4% decline and SGA rates a 30% decline during 1980-1994. Although there has been a 49% decline in late fetal deaths during 1980-1994, the rate remained higher for Pacific women than for Maori and European/other women. CONCLUSIONS: Despite residing in areas of high socioeconomic deprivation, which is associated with poor pregnancy outcomes for Maori and European/other women, Pacific women had better pregnancy outcomes, with lower preterm and SGA rates. The significant decline in rates of late fetal death during the past two decades is a cause for celebration; however, the rate remains higher for Pacific women than for other ethnic groups. Biological, cultural and social factors might explain the better pregnancy outcomes for Pacific women and these factors should be considered when developing future prevention programmes.     

Does augmented growth impose an increased risk of fetal death?

OBJECTIVE: Our purpose was to examine the risk of fetal death associated with augmented fetal growth. STUDY DESIGN: All live births recorded in Virginia between January 1, 1991, and December 31, 1993, were examined. Mortality rates were examined for infants born at or beyond 24 weeks' gestational age with weights between the 75th and 90th percentiles, from the 90th to the 95th percentile, and >95th percentile. RESULTS: Mortality rates were found to rise only slightly with birth weights >90th percentile. A recorded diagnosis of maternal diabetes, however, was associated with a significant risk in the presence of augmented fetal growth. Augmented fetal growth without maternal glucose intolerance showed no increase in mortality. CONCLUSION: Augmented fetal growth in the absence of maternal glucose intolerance appeared not to be associated with a significant increase in the risk of death among these births. Increased risk was found when augmented fetal growth was associated with maternal diabetes.     

The changing pattern of fetal death, 1961-1988.

The aim of this study was to assess any changes in cause-specific fetal death rates in the nonreferred population of a tertiary care unit. The fetal death rate (per 1000 births) among 88,651 births diminished from 11.5 in the 1960s to 5.1 in the 1980s. Fetal death due to intrapartum asphyxia and Rh isoimmunization has almost disappeared. Toxemia and diabetes continue to make similar and small contributions to fetal death rates. There has been a significant decline in unexplained antepartum fetal deaths and in those caused by fetal growth retardation, but no significant change in the death rate due to intrauterine infection or abruptio placentae. During the 1960s, the risk of fetal death was increased in women with hypertension, diabetes, or a history of stillbirth; during the 1980s, only women with a history of insulin-dependent diabetes were at risk. Improved application of current knowledge may help decrease the fetal death rate caused by fetal growth retardation. Reduction in deaths due to abruptio placentae, intrauterine infections, or lethal malformations, as well as unexplained antepartum deaths, appears to depend on better understanding of the etiology of these disorders.     

Four main reasons of maternal death in Poland between 1991-2000

Maternal death during pregnancy, labour and puerperium constitutes the main problem of prenatal medicine and still a major public health topic. In this work we analyses maternal deaths in Poland between 1991-2000. There were 4,404,641 live births and 462 maternal deaths. Among them there were 402 direct ("true") maternal deaths with mortality rate 9.1 per 100,000 live births and 60 indirect maternal deaths (rate 1.4). There were 218 cases of pregnancy associated deaths (rate 4.9). The main causes of direct maternal deaths were as follows: haemorrhage--33.6% (rate 3.1), sepsis--27.3% (rate 2.5), amniotic fluid embolism--22.4% (rate 2.0) and pregnancy induced hypertension 16.7% (rate 1.5). Increasing maternal age is one of important risk factor for mortality. Over 30% of direct pregnancy related deaths were noted within women above 35 years. Unsatisfactory antenatal care, management deficiency and patient's neglect were main risk factor foe fatal outcome. Practical conclusions should be issued as general rules, instructions and recommendations. Between one third to one half of the maternal deaths are considered to have been preventable.     

Maternal mortality: a twenty-year survey at the King Faisal University Hospital, Al-Khobar, Eastern Saudi Arabia.

This was an institutional study of all maternal deaths that occurred among 56422 total births at the King Faisal University Hospital, Al-Khobar, Saudi Arabia, between 1983 and 2002. The underlying cause of each maternal death and potentially avoidable factors were analysed. There were 16 maternal deaths in the hospital during the study period, giving a maternal mortality rate of 28.4/100,000 births. The leading cause of death was haemorrhage in seven (43.75%) patients, followed by pulmonary embolism in four (25%) and general anaesthesia in two (12.5%) mothers. The risk factors noted were maternal age 35 years and parity 5 coupled with iron deficiency anaemia. The main avoidable factors were failure of the patients to seek timely medical care and to follow medical advice. More than half the number of direct obstetrical causes of death was thought to be preventable. A rapidly changing attitude of women towards childbirth is occurring through progressively increasing female education and community health programmes in the region. Further reduction of maternal mortality rates in the community is envisaged through greater patient acceptance of medical advice, family spacing and proficient obstetric services.     

Low Birth-weight in NSW, 1987: a Population-based Study

Summary: The New South Wales perinatal data collection was used to examine the association between low birth-weight and some of its potential risk factors. The study population comprised all recorded singleton births to residents of NSW in 1987. Low birth-weight infants were categorized as either small for gestational age (SGA) or preterm (less than 37 weeks). Risk factors were analyzed separately for these categories. The risk factors examined were primarily demographic or reproductive history variables. Univariate analysis and multivariate logistic regression were used to evaluate the risk factors. The factors associated with SGA birth were mainly demographic (maternal age, parity, marital status, socioeconomic status, and ethnic group) while those associated with preterm birth had more reproductive history variables (maternal age, parity, marital status, prior spontaneous abortion, prior induced abortion, prior stillbirth or neonatal death, sex of infant). A first antenatal visit after 12 weeks had a statistically significant but small effect on both SGA and preterm birth.     

Ethnicity and birth outcome: New Zealand trends 1980-2001. Part 1. Introduction, methods, results and overview

BACKGROUND: New Zealand Government policy during the past decade has placed a high priority on closing socioeconomic and ethnic gaps in health outcome. AIM: To analyse New Zealand's trends in preterm and small for gestational age (SGA) births and late fetal deaths during 1980-2001 and to undertake ethnic specific analyses, resulting in risk factor profiles, for each ethnic group. METHODS: De-identified birth registration data from 1 189 120 singleton live births and 5775 stillbirths were analysed for the period 1980-2001. Outcomes of interest included preterm birth, SGA and late fetal death while explanatory variables included maternal ethnicity, age and New Zealand Deprivation Index decile. Trend analysis was undertaken for 1980-1994 while multivariate logistic regression was used to explore risk factors for 1996-2001. RESULTS: During 1980-1994, preterm birth rates were highest amongst Maori women. Preterm rates increased by 30% for European/other women, in contrast to non-significant declines of 7% for Maori women and 4% for Pacific women during this period. During the same period, rates of SGA were highest amongst Maori women. Rates of SGA declined by 30% for Pacific women, 25% for Maori women and 19% for European/other women during this period. Rates of late fetal death were highest amongst Pacific women during 1980-1994, but declined by 49% during this period, the rate of decline being similar for all ethnic groups. CONCLUSIONS: The marked differences in both trend data and risk factor profiles for women in New Zealand's largest ethnic groups would suggest that unless ethnicity is specifically taken into account in future policy and planning initiatives, the disparities seen in this analysis might well persist into future generations.     

The impact of prenatal care on neonatal deaths in the presence and absence of antenatal high-risk conditions

OBJECTIVE: The purpose of this study was to determine the association between prenatal care in the United States and the neonatal death rate in the presence and absence of antenatal high-risk conditions. STUDY DESIGN: Data were derived from the national perinatal mortality data sets for the years 1995 through 1997, which were provided by the National Center for Health Statistics. Analyses were restricted to singleton live births that occurred after 23 completed weeks of gestation. Multivariable logistic regression analyses were used to adjust for the presence or absence of various antenatal high-risk conditions, maternal age, gestational age at delivery, and birth weight. RESULTS: Of 10,530,608 singleton live births, 18,339 (1.7/1000 births) resulted in neonatal death. Neonatal death rates (per 1000 live births) were higher for African American infants compared with white infants in the presence (2.7 vs 1.5, respectively) and absence (10.7 vs 7.9, respectively) of prenatal care. Lack of prenatal care was associated with an increase in neonatal deaths, which was greater for infants born at > or =36 weeks of gestation (relative risk, 2.1; 95% CI, 1.8, 2.4). Lack of prenatal care was also associated with increased neonatal death rates in the presence of preterm premature rupture of the membranes (relative risk, 1.3; 95% CI, 1.1, 1.5), placenta previa (relative risk, 1.9; 95% CI, 1.2, 2.9), fetal growth restriction (relative risk, 1.7; 95% CI, 1.2, 1.6), and postterm pregnancy (relative risk, 1.4; 95% CI, 1.0, 2.9). CONCLUSION: In the United States, prenatal care is associated with fewer neonatal deaths in black and white infants. This beneficial effect was more pronounced for births that occurred at > or =36 weeks of gestation and in the presence of preterm premature rupture of the membranes, placenta previa, fetal growth restriction, and postterm pregnancy.     

Understanding perinatal mortality

The term perinatal death is used to describe antepartum and intrapartum stillbirths, and early neonatal deaths. At term, intrapartum stillbirth and neonatal death are collectively referred to as delivery related perinatal death, and the incidence in nulliparous and multiparous women is approximately one in 1000 and one in 2000 births, respectively. Associated factors include advanced maternal age, small for gestational age, fetal macrosomia, breech labour and previous caesarean delivery. The impact of obstetric interventions in labour on delivery related perinatal death, including rising rates of caesarean delivery, is complex and unclear. The incidence of overall perinatal death is falling mainly as a result of improvements in the management of premature neonates and from decreased deaths secondary to intrapartum anoxia at term. This review will provide an overview of perinatal mortality with a particular emphasis on delivery related perinatal death at term.     

Stillbirth and neonatal outcomes in South Australia, 1991-2000

OBJECTIVES: The purpose of this study was to determine the effect of maternal factors associated with impaired placental function on stillbirth and neonatal death rates in South Australia. STUDY DESIGN: From 1991 to 2000, the South Australian Pregnancy Outcome Unit's population database was searched to identify stillbirths and neonatal deaths in women with maternal medical conditions during pregnancy and in twin and singleton pregnancies. RESULTS: Women with hypertension and carbohydrate intolerance and who smoked during pregnancy had an increased risk of stillbirth. Women with twin pregnancies had a significantly higher stillbirth rate than for singletons at each week of gestational age. An increase in stillbirth rate at later gestations was seen with singletons, with a similar trend in twins but rising from 36 weeks' gestation. CONCLUSION: There is a clinical correlation between maternal factors associated with impaired placental function and increased risk of stillbirth, suggesting that intrauterine fetal death represents the mortality end point in a spectrum of intrauterine hypoxia.     

Adverse perinatal outcomes among interracial couples in the United States

OBJECTIVE: We examined the association between parental race and stillbirth and adverse perinatal and infant outcomes. METHODS: We conducted a retrospective cohort analysis using the 1995-2001 linked birth and infant death files that are composed of live births and fetal and infant deaths in the United States. The study included singleton births delivered at 20 or more weeks of gestation with a fetus weighing 500 g or more (N = 21,005,786). Parental race was categorized as mother white-father white, mother white-father black, mother black-father white, and mother black-father black. Multivariable logistic regression analysis was performed to examine the association between parental race and risks of stillbirth (at > or = 20 weeks), small for gestational age (defined as birth weight < 5th and < 10th percentile for gestational age), and early neonatal (< 7 days), late neonatal (7-27 days), and postneonatal (28-364 days) mortality. All analyses were adjusted for the confounding effects of maternal age, education, trimester at which prenatal care began, parity, marital status, and smoking during pregnancy. RESULTS: Although risks varied across parental race categories, stillbirth was associated with a higher-than-expected risk for interracial couples: mother white-father black, relative risk (RR) 1.17 (95% confidence interval [CI] 1.10-1.26) and mother black-father white, RR 1.37 (95% CI 1.21-1.54) compared with mother white-father white parents. The RR for stillbirth was even higher among mother black-father black parents (RR 1.67, 95% CI 1.62-1.72). The overall patterns of association for small for gestational age births (< 5th and < 10th percentile) and early neonatal mortality were similar to those seen for stillbirth. CONCLUSION: There is an increased risk of adverse perinatal outcomes for interracial couples, including stillbirth, small for gestational age infants, and neonatal mortality. LEVEL OF EVIDENCE: II-2.     

The 1988 National Maternal and Infant Health Survey: Design,Content, and Data Availability

ABSTRACT: The 1988 National Maternal and Infant Health Survey was conducted by the National Center for Health Statistics to study factors related to poor pregnancy outcome, such as adequacy of prenatal care; inadequate and excessive weight gain during pregnancy; maternal smoking, drinking, and drug use; and pregnancy and delivery complications. The survey is a nationally representative sample of 11,000 women who had live births, 4000 who had late fetal deaths, and 6000 who had infant deaths in 1988. Mothers were mailed questionnaires based on information from certificates of live birth, reports of fetal death, and certificates of infant death. Information supplied by the mother, prenatal care providers, and hospitals of delivery was linked with the vital records to expand knowledge of maternal and infant health in the United States. Data collection from the Longitudinal Followup of mothers in the survey began in January 1991. It provides information on health and development of low- and very low-birthweight babies, child care and safety, maternal health, maternal depression, and plans for adoption and foster care. Both surveys will provide useful data for clinicians in maternal and child health.     

Socio-economic, demographic and obstetric risk factors for late fetal death of unknown etiology in Lithuania: a case--referent study

BACKGROUND: The purpose of this study was to evaluate the association between third trimester unexplained prelabor fetal deaths and various socio-economic, demographic and obstetric factors in Lithuania. METHODS: A case-referent study on 58 women with third trimester fetal death and 116 women with live fetus at term was carried out. Inclusion criteria for women in the first group (cases) were: prelabor fetal death of unknown etiology, singleton pregnancy >26 weeks of gestation and intact fetal membranes. For each case two referent women were recruited, admitted during the same period in active phase of labor at term (>37 weeks of gestation) with intact fetal membranes and fetus alive. Data were obtained by interview, anthropometry and by reviewing the medical records. Several potential socio-economic, demographic and obstetrical risk factors for unexplained fetal death were investigated. RESULTS: Univariate analyses determined several factors that were associated with fetal death of unknown etiology: low educational level, single marital status, low income, etc. After secondary logistic regression analysis only three independent variables remained significantly associated with otherwise unexplained stillbirth: small for gestational age fetus (OR 29.6; 95% CI 6.2-141.6), low income (OR 7.4; 95% CI 3.1-17.6), and maternal white blood cell count more than 16,000/mm3 (OR 5.4; 95% CI 1.4-21.6). Body mass index, smoking, occupation of women and other evaluated parameters were not confirmed to be significant risk factors. CONCLUSION: Small for gestational age fetus, low income and elevated maternal white blood cell count are factors significantly associated with late prelabor fetal death in Lithuania.