Prenatal care and black-white fetal death disparity in the United States: heterogeneity by high-risk conditions

OBJECTIVE: To determine the impact of prenatal care in the United States on the fetal death rate in the presence and absence of obstetric and medical high-risk conditions, and to explore the role of these high risk conditions in contributing to the black-white disparity. METHODS: This is a population-based, retrospective cohort study using the national perinatal mortality data for 1995-1997 assembled by the National Center for Health Statistics. Fetal death rate (per 1000 births) and adjusted relative risks were derived from multivariable logistic regression models. RESULTS: Of 10,560,077 singleton births, 29,469 (2.8 per 1000) resulted in fetal death. Fetal death rates were higher for blacks than whites in the presence (4.2 versus 2.4 per 1000) and absence (17.2 versus 2.5 per 1000) of prenatal care. Lack of prenatal care increased the (adjusted) relative risk for fetal death 2.9-fold in blacks and 3.4-fold in whites. Blacks were 3.3 times more likely to have no prenatal care compared with whites. Over 20% of all fetal deaths were associated with growth restriction and placental abruption, both in the presence and absence of prenatal care. Lack of prenatal care was associated with increased fetal death rates for both blacks and whites in the presence and absence of high-risk conditions. CONCLUSION: In the Unites States, strategies to increase prenatal care participation, especially among blacks, are expected to decrease fetal death rates.     

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.     

Routine screening with fetal echocardiography for prenatal diagnosis of congenital heart disease

Congenital cardiac anomalies are the most common congenital anomalies, occurring in approximately eight of 1000 live births. Proper perinatal and neonatal management is dependent upon accurate prenatal diagnosis. Approximately 10% of fetuses with cardiac abnormalities have identified risk factors; hence, most of the anomalies occur in pregnancies without prenatal risk factors. The application of detailed fetal echocardiography for prenatal screening, at present reserved mainly for high-risk cases, requires further evaluation before being recommended for the general population.

This article presents our experience of evaluating the accuracy of fetal echocardiography as a screening method in detecting cardiac anomalies in the general population of Singapore. We reviewed data from 39 808 pregnant women who received antenatal care at the National University Hospital, Singapore, between January 1986 and December 1994, and who underwent routine fetal echocardiography at 21-22 weeks of gestation. We identified 294 cases of congenital heart defects by fetal echocardiography. We obtained a sensitivity of 85.4% for the detection of congenital heart disease, and a specificity of 99.9% to rule out such anomalies. Our positive and negative predictive rates were 87.7% and 99.9%, respectively.

We recommend routine screening by echocardiography of all pregnancies at 21-22 weeks of gestation, irrespective of risk stratifcation, for the prenatal detection of cardiac anomalies, in order to improve perinatal management.     

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

OBJECTIVE: This study was undertaken to determine the association, if any, between prenatal care and postneonatal death in the presence and absence of high-risk pregnancy conditions. STUDY DESIGN: Data were derived from the national linked birth/infant death data set for the years 1995 to 1997 provided by the National Center for Health Statistics. Analyses were restricted to singleton live births that occurred after 23 completed weeks of gestation. Multiple births, congenital malformations, chromosomal abnormalities, missing data on gestational age, and birth weight less than 500 g were excluded. Multivariable logistic regression analyses were used to adjust for various antenatal high-risk conditions, maternal age, gravidity, gestational age at delivery, birth weight, maternal education, marital status, smoking, and alcohol use. Postneonatal death rate was defined as the number of deaths between 28 and 365 days of life per 1,000 neonatal survivors. RESULTS: For 10,512,269 singleton live births analyzed, 21,962 (2.1 per 1,000) resulted in postneonatal death. Postneonatal death rates were higher for African American women than white women in the presence (3.8 vs 1.7 per 1,000) and absence (11.2 vs 5.3 per 1,000) of prenatal care. Lack of prenatal care was associated with increased relative risk (RR) for postneonatal death, 1.8-fold in African American women and 1.6-fold in white women. Lack of prenatal care was associated with increased postneonatal death rates to a similar degree for the individual high-risk pregnancy conditions for both African American and white women. Lack of prenatal care was associated with increased postneonatal death rates, especially in the presence of postterm pregnancy (RR 2.3, 95% CI 1.6, 3.1), pregnancy-induced hypertension (RR 2.2, 95% CI 1.5, 3.4), intrapartum fever (RR 2.1, 95% CI 1.2, 3.5), and small-for-gestational-age infant (RR 1.6, 95% CI 1.3, 2.0). CONCLUSION: Lack of prenatal care should be considered as a high-risk factor for postneonatal death for both African American and white women, especially if the pregnancy has been complicated by postdates, pregnancy-induced hypertension, intrapartum fever or small-for-gestational-age infant.     

Perinatal mortality and neonatal morbidity from 1974 till 1979

To collect data on fetal and infant mortality in Spain 15,222 live births were investigated between 1974-1979 in a large metropolitan hospital. Perinatal mortality was 21.18/1000 in 1974, and 12.48/1000 in 1979, an average of 16.88/1000 over the 5-year period. Early fetal death was extremely high, 8.21/1000, possibly due to the fact that most women had never had any prenatal care. Mortality during delivery was 2.63/1000; early neonatal mortality was 6.04/1000; and late fetal mortality was 10.83/1000. Of the 15,222 newborns, 2381 (15.64%), needed special care: 2.14% needed intensive care, 4.41% needed average care, and 9.09% needed minimal care. Syndromes observed were: hypoxia (6.94%); low birth weight (4.16%); malformations; jaundice; and respiratory insufficiency.     

Maternity Care and Outcomes in a High-Risk Service: The North Central Bronx Hospital Experience

ABSTRACT: The maternity service of the North Central Bronx Hospital, a New York City municipal hospital for the medically indigent, has demonstrated that good maternal and infant outcomes can be obtained in an unselected population of disadvantaged women by using obstetric interventions only when medically indicated. Approximately 70 percent of the mothers cared for in the service are considered at risk or high risk. Of the 3287 deliveries in 1988, 86.1 percent were performed by the midwives on staff. Midwives were the primary providers of prenatal, intrapartum, and postpartum care for all low-risk mothers, and comanaged with the attending obstetricians the care of all high-risk mothers. The cesarean section rate was 11.8 percent, and the rate of instrumental delivery was 0.3 percent, with minimal use of oxytocin augmentation (6.4%). Among the 3323 infants delivered in 1988, the last full year before an obstetric residency program was established, the rate of those requiring special or intensive care was 11.1 percent, and neonatal mortality was 9.2 per 1000 live births for all birth weights and 3.7 per 1000 for infants over 1000 g. The experience gained from 10 years and over 25,000 births suggests that the maternity care of both high- and low-risk mothers could be improved by minimizing obstetric intervention whenever possible.     

Audit of neonatal deaths of nonmalformed infants of 34 or more weeks' gestation: unavoidable catastrophic events or suboptimal care?

BACKGROUND: The neonatal death rate (death < or = 28 days/1000 live births) has decreased and the level is now so low that it has been questioned whether further improvement is possible. The aim of this study was to categorize nonmalformed infants of 34 weeks' or more gestational age dying in the neonatal period to analyze if these deaths might have been prevented. MATERIAL AND METHODS: We used the audit method to study neonatal deaths during 1986-98 in a county population of approximately 240 000 inhabitants. RESULTS: Twenty-six neonatal deaths from a population of 41 901 live births were analyzed. The neonatal deaths were found to be associated with antepartum hypoxia (six cases); intrapartum catastrophes (seven cases); intrapartum monitoring deficiencies (five cases); resuscitation and stabilization after birth (two cases); infection (one case); sudden infant death syndrome (four cases); and peritonitis (died at home, one case). Suboptimal care was recorded in 16 cases. Neonatal death was unlikely to be associated with suboptimal care in six cases, but in 10 cases suboptimal care might or was likely to have brought about the fatal outcome. CONCLUSION: Avoiding suboptimal care might or is likely to prevent neonatal death in 10/26 (38.5%) of nonmalformed infants of 34 weeks' or more gestational age. Such improvements may, however, only slightly influence the neonatal death rate, with a reduction from 4.4 to 4.2/1000 live births.     

Impact of a permissive abortion statute on community health care

3542 first-trimester and 876 second-trimester abortions were performed at City Hospital Center, Elmhurst, New York, from July 1,1970 to June 30, 1972. The relatively stable, semi-closed population of women involved permitted an analysis of the effect of a permissive abortion law and practice on general health care. Tables of patient characteristics and abortion statistics over the period indicated the following: a present rate of abortion of 1009 per 1000 births; no maternal mortality; a reduction in maternal morbidity as experience with abortion techniques increased; a reduction by 44.4% of the number of deliveries without prenatal care, by 16.5% of premature deliveries, by 23.1% of immature deliveries; and a 29.2% reduction of the perinatal mortality rate. Also shown was a marked change in age distribution from the beginning of the period to the end: the incidence of abortions decreased among patients less than 20 years old by 47.1%, and among those over 35 by 46.7%. Additionally, the number of abortions among "never-married" women was reduced by 59.5%. There was a threefold increase in utilization of the antepartum clinic during the first trimester and an increase in prenatal visits. Incidence of spontaneous early abortion was reduced 52.2% and septic abortions were almost entirely eliminated. Postpartum psychosis decreased by half, the rate of voluntary sterilization doubled, and registration of new patients for family planning increased by 116%. Improvements were also seen in pregnancy testing and counseling, in cancer detection through an increase in the number of papanicolaou smears, screening for venereal disease and sickle cell trait/disease, and in the detection of medical, surgical and psychosocial diseases. Pregnancies were largely eliminated in "high-risk" obstetric patients from the childbearing population such as the very young or old, the unmarried, or the emotionally disturbed. The influence of liberalized abortion statutes was shown to have served the community not only by solving immediate health crises but also by contributing to the development of a total health care program.     

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.     

Fetal death during labor: an epidemiologic indicator of level of obstetric care

The effect of level of perinatal care on rates of intrapartum fetal death was studied in births of infants weighing greater than 1000 gm in New York City in 1976 to 1978. With potential confounding by birth weight, gestational age, and several other variables controlled, intrapartum fetal death rates decreased as intensiveness of care increased. Compared with births in Level 3 maternity units (perinatal intensive care), births in Level 1 units (community hospitals) had a 61% excess risk of intrapartum fetal death (p less than 0.01) and births in Level 2 units (intermediate level of care) had a 35% excess risk (p = 0.06). The effect of hospital level on intrapartum fetal death rates could not be attributed to differences in the classification of fetal deaths during labor across hospital levels, since no compensatory differences in late antepartum fetal death rates were found. Our findings in a total population are compatible with several studies carried out in single hospitals that have reported declines in intrapartum fetal death rates, especially in births more closely attended during labor. Fetal deaths that occur in labor, as contrasted with fetal deaths occurring before labor, constitute a perinatal outcome that is especially sensitive to level of obstetric care.     

Association of caesarean delivery for first birth with placenta praevia and placental abruption in second pregnancy

Objective  To quantify the risk of placenta praevia and placental abruption in singleton, second pregnancies after a caesarean delivery of the first pregnancy.
Design  Retrospective cohort study.
Setting  Linked birth and infant mortality database of the USA between 1995 and 2000.
Population  A total of 5 146 742 singleton second pregnancies were available for the final analysis after excluding missing information.
Methods  Multiple logistic regressions were used to describe the relationship between caesarean section at first birth and placenta praevia and placental abruption in second-birth singletons.
Main outcome measures  Placenta praevia and placental abruption.
Results  Placenta praevia was recorded in 4.4 per 1000 second-birth singletons whose first births delivered by caesarean section and 2.7 per 1000 second-birth singletons whose first births delivered vaginally. About 6.8 per 1000 births were complicated with placental abruption in second-birth singletons whose first births delivered by caesarean section and 4.8 per 1000 birth in second-birth singletons whose first births delivered vaginally. The adjusted odds ratio (95% CIs) of previous caesarean section for placenta praevia in following second pregnancies was 1.47 (1.41, 1.52) after controlling for maternal age, race, education, marital status, maternal drinking and smoking during pregnancy, adequacy of prenatal care, and fetal gender. The corresponding figure for placental abruption was 1.40 (1.36, 1.45).
Conclusion  Caesarean section for first live birth is associated with a 47% increased risk of placenta praevia and 40% increased risk of placental abruption in second pregnancy with a singleton.     

The relationship between utilization of prenatal care and Down syndrome live births.

OBJECTIVE: This study evaluated whether utilization of prenatal care, as measured by the Kessner index, affects the number of Down syndrome live births. METHODS: A retrospective analysis of birth certificate data of Down syndrome live births comparing 1989 to 2001 by year, maternal age, gestational age at first prenatal visit, and adequacy of prenatal care according to Kessner categories of adequacy of prenatal care. RESULTS: Down syndrome live births were inversely correlated with adequacy of prenatal care. Reductions in Down syndrome live births were seen in all categories of prenatal care in all age groups. In 2001 a minimum 30% reduction was seen in any category rising to a 58% reduction in women > or =35 years with adequate prenatal care. The largest reductions were seen in women > or =35 years of age. CONCLUSIONS: Reductions in Down syndrome live births occurred in all age groups between 1989 and 2001. Utilization of prenatal care as measured by the Kessner index was associated with reductions in Down syndrome live births, with a greater reduction in women > or =35 years of age.     

Reducing neonatal mortality rate with nurse-midwives

Newborn health indices were measured before, during, and after a demonstration nurse-midwife program introduced to relieve a health manpower shortage at a county hospital in rural California. During the program, prenatal care increased, and prematurity and neonatal mortality rate decreased at the county hospital. After the 3 year program, prenatal care decreased while prematurity rose from 6.6 to 9.8 per cent (p<0.02) and neonatal mortality rate rose from 10.3 to 32.1 per 1,000 live births (p<0.005). No significant changes occurred in the same indices for births elsewhere in the county throughout the period of the study. It is concluded that the discontinuation of the nurse-midwives' services was the major factor in these changes, and it is suggested that nurse-midwives be used more extensively.     

Midwifery in Israel

Socialized medicine provides free and easily accessible prenatal and intrapartum care in Israel. Mothers also receive the equivalent of dollars 100 to dollars 300 after delivering in hospital. The infant mortality rate is 5.5 per 1000 live births. Uncomplicated births (80%) are attended by midwives. Midwives routinely rupture membranes, attach electronic fetal monitoring, give intravenous fluids and deliver in lithotomy position. Approximately 15% of women undergo induction, 20% augmentation, 40% epidural, 30% episiotomy, 17% cesarean section. In 2003, 1% of births were cesareans by maternal request, rather than medical necessity, and 0.1% of births were planned homebirths. The system processes 140,000 births per year with good medical outcomes, especially considering Israel is only 56 years old.     

The relationship between utilization of prenatal care and Down syndrome live births

Objective. This study evaluated whether utilization of prenatal care, as measured by the Kessner index, affects the number of Down syndrome live births.

Methods. A retrospective analysis of birth certificate data of Down syndrome live births comparing 1989 to 2001 by year, maternal age, gestational age at first prenatal visit, and adequacy of prenatal care according to Kessner categories of adequacy of prenatal care.

Results. Down syndrome live births were inversely correlated with adequacy of prenatal care. Reductions in Down syndrome live births were seen in all categories of prenatal care in all age groups. In 2001 a minimum 30% reduction was seen in any category rising to a 58% reduction in women ≥35 years with adequate prenatal care. The largest reductions were seen in women ≥35 years of age.

Conclusions. Reductions in Down syndrome live births occurred in all age groups between 1989 and 2001. Utilization of prenatal care as measured by the Kessner index was associated with reductions in Down syndrome live births, with a greater reduction in women ≥35 years of age.     

Risk of a Down syndrome live birth in women 45 years of age and older

OBJECTIVES: To determine the risk of a Down syndrome (DS) live birth for women 45 years of age and over. METHODS: A meta-analysis of data from five published articles, 13 EUROCAT congenital anomaly population registers and two unpublished sources. RESULTS: Information was available on the number of DS live births occurring amongst 13,745 live births to women 45 years of age and over. Information was also available on DS pregnancies diagnosed prenatally that were subsequently terminated. These pregnancies were adjusted for expected fetal loss to estimate the number of live births that would have occurred in the absence of prenatal diagnoses, when a total of 471 DS live births were estimated to have occurred. The risk of a DS birth did not increase for women 45 years of age and over. The average risk was 34 per 1000 births (95% CI: 31-37). CONCLUSION: The risk of a DS live birth for women 45 years of age and over is considerably lower than has often been previously assumed. The most likely explanation is that women of this age are more likely to miscarry DS pregnancies than younger mothers.     

Epidemiology of preeclampsia and eclampsia in the United States, 1979-1986

Preeclampsia and eclampsia continue to be among the leading causes of maternal death. However, national estimates of the occurrence of these conditions have not been available. To derive national rates of preeclampsia and eclampsia and to characterize the women at highest risk of the development of these conditions, we analyzed data from the National Hospital Discharge Survey for the years 1979 through 1986. We found that 26 per 1000 births during this period were complicated by preeclampsia and 0.56 per 1000 births were complicated by eclampsia. The rate of mild or unspecified preeclampsia remained constant over the study period. In contrast, the rate of severe preeclampsia increased sharply and the rate of eclampsia declined by 36%. Maternal age less than 20 years old was the strongest risk factor for both preeclampsia and eclampsia. These data indicate a need for improved prenatal care among teenagers.     

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.     

The impact of prenatal care in the United States on preterm births in the presence and absence of antenatal high-risk conditions

OBJECTIVE: This study was undertaken to determine the association between prenatal care in the United States and preterm birth rate in the presence, as well as absence, of high-risk pregnancy conditions for African American and white women. STUDY DESIGN: Data were derived from the natality data set for the years 1995 to 1998 provided by the National Center for Health Statistics. Analyses were restricted to singleton live births that occurred at >/=20 weeks' gestation. Multiple births, fetal deaths, congenital malformations, chromosomal abnormalities, missing data on gestational age, and birth weight less than 500 g were excluded. Multivariable logistic regression analyses were used to adjust for the presence or absence of various antenatal high-risk conditions, maternal age, gravidity, marital status, smoking, alcohol, and education. Prenatal care was considered present if there was one or more prenatal visits. Preterm delivery was defined as delivery at less than 37 completed weeks of gestation. RESULTS: For 14,071,757 births analyzed, 1,348,643 (9.6%) resulted in preterm birth. Preterm birth rates were higher for African American women than white women in the presence (15.1% vs 8.3%) and absence (34.9% vs 21.9%) of prenatal care. The absence of prenatal care increased the relative risk for preterm birth 2.8-fold in both African American and white women. There was an inverse dose-response relationship between the number of prenatal visits and the gestational age at delivery both among African American and white women. Lack of prenatal care was associated with increased preterm birth rates to a similar degree in the presence of pregnancy complications for both African American and white women, ranging from 1.6-fold to 5.5-fold for the various antenatal high-risk conditions. CONCLUSION: In the United States, prenatal care is associated with fewer preterm births in the presence, as well as absence of high-risk conditions for both African American and white women. Strategies to increase prenatal care participation may decrease preterm birth rates.     

Contribution of late fetal deaths to US perinatal mortality rates, 1995-1998

We analyzed US fetal death and linked infant birth-death certificate data for 1995-1998 to evaluate perinatal deaths (late fetal deaths [> or = 28 weeks' gestation] and early neonatal deaths [< or = 7 days of life]) by race, Hispanic ethnicity, state of residence, and selected demographic characteristics. We also compared components of perinatal mortality, late fetal deaths, and early neonatal deaths, by birthweight, gestational age, and selected maternal medical conditions during pregnancy. From 1995 through 1998, there were 221,767 fetal deaths at > or = 20 weeks' gestation and infant deaths at less than 1 year. Of these, 113,421 (51%) were perinatal deaths; late fetal deaths accounted for 47% of perinatal deaths. The total perinatal mortality rate declined 5.3%, from 7.5 to 7.1 per 1,000 live births plus late fetal deaths. Blacks experienced higher perinatal mortality rates than whites (rate ratio = 2.1). Among perinatal deaths > or = 28 weeks' gestation, the ratio of fetal to neonatal deaths was 3.4 among blacks and 2.4 among whites. State-specific rates ranged from 5.2 to 13.1 per 1,000 live births plus late fetal deaths. Although late fetal deaths are not included in routine statistics of pregnancy outcomes, these deaths represent a large proportion of adverse pregnancy outcomes. Surveillance of perinatal mortality provides a more complete picture of the health of women, fetuses, and newborns. Improving the quality of surveillance data regarding fetal deaths is essential for more effective use of these data. This information can be used to prevent excess perinatal deaths and reduce disparities in pregnancy outcomes among high-risk subgroups identified by individual and population characteristics.