Profile of maternal and foetal complications during labour and delivery among women giving birth in hospitals in Matlab and Chandpur, Bangladesh

Worldwide, for an estimated 358,000 women, pregnancy and childbirth end in death and mourning, and beyond these maternal deaths, 9-10% of pregnant women or about 14 million women per year suffer from acute maternal complications. This paper documents the types and severity of maternal and foetal complications among women who gave birth in hospitals in Matlab and Chandpur, Bangladesh, during 2007-2008. The Community Health Research Workers (CHRWs) of the icddr,b service area in Matlab prospectively collected data for the study from 4,817 women on their places of delivery and pregnancy outcomes. Of them, 3,010 (62.5%) gave birth in different hospitals in Matlab and/or Chandpur and beyond. Review of hospital-records was attempted for 2,102 women who gave birth only in the Matlab Hospital of icddr,b and in other public and private hospitals in the Matlab and Chandpur area. Among those, 1,927 (91.7%) records were found and reviewed by a physician. By reviewing the hospital-records, 7.3% of the women (n=1,927) who gave birth in the local hospitals were diagnosed with a severe maternal complication, and 16.1% with a less-severe maternal complication. Abortion cases--either spontaneous or induced--were excluded from the analysis. Over 12% of all births were delivered by caesarean section (CS). For a substantial proportion (12.5%) of CS, no clear medical indication was recorded in the hospital-register. Twelve maternal deaths occurred during the study period; most (83%) of them had been in contact with a hospital before death. Recommendations include standardization of the hospital record-keeping system, proper monitoring of indications of CS, and introduction of maternal death audit for further improvement of the quality of care in public and private hospitals in rural Bangladesh.

Maternal and fetal factors associated with mortality and morbidity in a multi-racial/ethnic registry of anti-SSA/Ro-associated cardiac neonatal lupus

BACKGROUND

Cardiac manifestations of neonatal lupus include conduction disease and, rarely, an isolated cardiomyopathy. This study was initiated to determine the mortality and morbidity of cardiac neonatal lupus and associated risk factors in a multi-racial/ethnic US-based registry to provide insights into the pathogenesis of antibody-mediated injury and data for counseling.

METHODS AND RESULTS

Three hundred twenty-five offspring exposed to maternal anti-SSA/Ro antibodies with cardiac neonatal lupus met entry criteria. Maternal, fetal echocardiographic, and neonatal risk factors were assessed for association with mortality. Fifty-seven (17.5%) died, 30% in utero. The probability of in utero death was 6%. The cumulative probability of survival at 10 years for a child born alive was 86%. Fetal echocardiographic risk factors associated with increased mortality in a multivariable analysis of all cases included hydrops and endocardial fibroelastosis. Significant predictors of in utero death were hydrops and earlier diagnosis, and of postnatal death were hydrops, endocardial fibroelastosis, and lower ventricular rate. Isolated heart block was associated with a 7.8% case fatality rate, whereas the concomitant presence of dilated cardiomyopathy or endocardial fibroelastosis quadrupled the case fatality rate. There was a significantly higher case fatality rate in minorities compared with whites, who were at a lower risk of hydrops and endocardial fibroelastosis. Pacing was required in 70%; cardiac transplantation was required in 4 children.

CONCLUSION

Nearly one fifth of fetuses who develop cardiac neonatal lupus die of complications predicted by echocardiographic abnormalities consistent with antibody-associated disease beyond the atrioventricular node. The disparity in outcomes observed between minorities and whites warrants further investigation.

Frequency of echogenic intracardiac focus by race/ethnicity in euploid fetuses

OBJECTIVE

To determine the frequency of echogenic intracardiac focus (EIF) by race/ethnicity.

METHODS

We performed a retrospective analysis from January 1996 through June 2003. We reviewed all initial sonograms from 14 to 23 weeks gestation in singleton pregnancies. Mothers on admission for delivery provided race/ethnicity.

RESULTS

There were 8207 ultrasounds and deliveries that met study criteria. There were 4636 (56.5%) Caucasian, 2087 (25.4%) African-American, 1261 (15.4%) Hispanic and 223 (2.7 %) Asian subjects. There were 347 (4.2%) EIF detected. The frequency by race/ethnicity varied significantly (p < 0.0001).

CONCLUSIONS

This large, population-based study showed that fetuses born to Asian mothers were significantly more likely to have an EIF. This racial difference should be taken into account when counseling patients about the potential for Down syndrome.

Medians and correction factors for biochemical and ultrasound markers in Chinese women undergoing first-trimester screening for trisomy 21

OBJECTIVE

To establish normative values and distribution parameters of first-trimester maternal serum free beta-human chorionic gonadotropin (beta-hCG), pregnancy-associated plasma protein-A (PAPP-A) and fetal nuchal translucency (NT) thickness in Chinese women and to examine the effects of covariates on their levels.

METHODS

Maternal serum free beta-hCG, PAPP-A and fetal NT were measured in 9762 women presenting for first-trimester combined screening for Down syndrome at 11 to 14 weeks of gestation. Individuals' markers were converted to multiples of the median (MoM) using expected medians estimated by performing a weighted regression analysis. Multivariate regression analysis was performed to assess the influence of maternal weight, parity, ethnicity, chorionicity in twin pregnancies, smoking, insulin-dependent diabetes and mode of conception on individual marker MoM levels.

RESULTS

Both free beta-hCG and PAPP-A median values demonstrated an exponential relationship with gestational age in days. Multivariate regression analysis indicated that free beta-hCG MoM was statistically significantly dependent on maternal weight (P < 0.0001) and chorionicity in twin pregnancy (both monochorionic and dichorionic P < 0.0001), that PAPP-A MoM was dependent on maternal weight (P < 0.0001), parity (P < 0.0001), chorionicity in twin pregnancy (both monochorionic and dichorionic P < 0.0001) and mode of conception (P = 0.002), and that fetal NT-MoM was dependent on maternal weight (P = 0.0006) and mode of conception (P = 0.012).

CONCLUSION

Normative values have been generated to allow conversion of NT, free beta-hCG and PAPP-A to their MoM equivalents and correction factors have been determined to adjust for maternal and pregnancy characteristics for use in ethnic Chinese women undergoing first-trimester screening for aneuploidy.

First-trimester screening for trisomy 21 by free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A: impact of maternal and pregnancy characteristics

OBJECTIVES

To use multiple regression analysis to define the contribution of maternal variables that influence the measured concentration of free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A), and the interaction between these covariates, in first-trimester biochemical screening for trisomy 21.

METHODS

This was a multicenter study of prospective screening for trisomy 21 by a combination of fetal nuchal translucency thickness, and maternal serum free beta-hCG and PAPP-A at 11 + 0 to 13 + 6 weeks of gestation. In the pregnancies subsequently found to have trisomy 21 and in those with no obvious chromosomal abnormality, we used multiple regression analysis to account for pregnancy characteristics that influence the measured concentrations of free beta-hCG and PAPP-A. We fitted Gaussian distributions to the distribution of log multiples of the median (MoM) values in trisomy 21 and in unaffected pregnancies.

RESULTS

There were 491 cases of trisomy 21 and 96 803 chromosomally normal pregnancies. Compared with values in Caucasian women, those who were parous, non-smokers and those who conceived spontaneously, PAPP-A was 57% higher in women of Afro-Caribbean origin, 3% higher in South Asians, 9% higher in East Asians, 2% higher in nulliparous women, 17% lower in smokers and 10% lower in those conceiving by in-vitro fertilization (IVF). Free beta-hCG was 12% higher in women of Afro-Caribbean origin, 9% lower in South Asians, 8% higher in East Asians, 2% higher in nulliparous women, 4% lower in smokers and 9% higher in those conceiving by IVF. In screening for trisomy 21 by maternal age and serum free beta-hCG and PAPP-A the estimated detection rate was 65% for a false-positive rate of 5%.

CONCLUSIONS

In first-trimester biochemical screening for trisomy 21 it is essential to adjust the measured values of free beta-hCG and PAPP-A for maternal and pregnancy characteristics.

[Mutation screening and prenatal diagnosis of hidrotic ectodermal dysplasia in a Chinese family]

OBJECTIVE

To analyze the mutations in Cx30 gene in a Chinese family with hidrotic ectodermal dysplasia (HED) and to make prenatal diagnosis on the embryo which has been pregnant for 5 months.

METHODS

A family including 2 affected and 4 unaffected individuals was collected, and their informed consents were obtained. The affected woman had a five-month pregnancy. An 884 bp fragment containing the whole GJB6 coding sequence was amplified by PCR and the products were bi-direction sequenced directly. The mutation was further confirmed with restriction endoenzyme digesting. On the base of successful gene diagnosis, the following detection procedure on the pregnant baby was performed. First the whole coding region of Cx30 was amplified using primers Cx30-F and Cx30-R and the PCR products were digested by Hae II. Then the PCR products were cloned into pUCm-T vector. Blue-white blot screening method and PCR-restriction endoenzyme digesting technique were used to identify the correct clones. The mutant allele clone was sequenced to confirmed the mutation.

RESULTS

A heterozygous missense mutation 263C --> T in the Cx30 gene was detected in the affected little girl and her affected mother, which led to an amino acid substitution (A88V) in the second transmembrane domain of GJB6. The mutation was confirmed by Hae II digestion. A88V mutant allele cannot be cut while the wild normal allele can be cut into two fragments, 520 and 278 bp. The result of analyse on the five-month pregnancy show the embryo carried the A88V mutation too. So the embryo will be a patient.

CONCLUSION

An A88V missense mutation in the Cx30 gene can also cause HED in Chinese Han population. Based on the gene diagnosis, prenatal diagnosis can be played using bi-direction sequencing and confirmed with restriction endoenzyme digesting.

Medians for second-trimester maternal serum markers: geographical differences and variation caused by median multiples-of-median equations

OBJECTIVES

To establish gestational age-specific mid-trimester normal medians for the prenatal serum markers alpha fetoprotein (AFP), human chorionic gonadotropin (HCG) and unconjugated oestriol (uE3) for a Belgian population by using the Beckman Coulter Access chemiluminiscent immunoassays; to compare these data with data obtained from other geographical regions; to propose regression coefficients for regressed medians and analyse variation induced by different regression equations; to evaluate the effect of formulas used for gestation correction on estimating risk in Down's syndrome.

DESIGN

Data derived from 862 fresh serum samples from women being screened for Down's syndrome pregnancy, composed of selected pregnancies deemed to be normal, were examined in a retrospective study. Regressed medians were calculated by using a first-degree logarithmic-linear fit of the raw data. Multiples-of-median (MoM) values estimated by using a simple logarithmic-linear equation were compared with those calculated with higher-degree polynomials chosen with a goodness-of-fit analysis. Model-specific variation was estimated and the effect on risk for Down's syndrome was evaluated.

RESULTS

Regressed medians (Y) for Access serum markers AFP (IU/ml), HCG (IU/ml) and uE3 (nmol/l) for a Belgian population can be estimated with the equation Y = 10((A+BX)) with X = decimal weeks. The best fit was obtained with a third-degree and a second-degree polynomial for AFP and uE3, respectively. Differences between the medians and among the slopes of the geographical populations were found to be significant (analysis of covariance, p<0.001).

CONCLUSIONS

Belgian marker medians versus gestational time are found to show a pattern that is similar to that in the literature. The log-linear equation is observed to give a good fit and can be suggested as a tool for calculating median MoM values for Belgian laboratories that use Access biochemical prenatal markers.

Ethnicity and other factors that may affect the prevalence of echogenic intracardiac foci in the fetus

PURPOSE

To study ethnicity and other possible factors that may affect the incidence of echogenic intracardiac foci (EIF) when detected via sonographic examination.

MATERIALS AND METHODS

Patients were referred to our institution for sonographic evaluation from a wide range of practice formats, including both private obstetric practices as well as community outpatient clinics. The study protocol included presence or absence of EIF, maternal age, ethnicity, gestational age during the examination, optimal versus suboptimal scans, presence of other fetal malformations and sonographic markers, and presence of chromosomal anomalies. Fetal outcome was ascertained in 90% of the study group. For statistical analysis, the chi-square test and the Student t-test were used.

RESULTS

The study group included 1,543 patients who had a fetal anatomy survey between 16 and 24 weeks' gestation. The prevalence of EIF was similar in all 4 ethnic groups (Asian, Hispanic, black, and white). There were 76 cases of EIF-an overall prevalence of 4.9%. Seventy-one of these cases were isolated in the left ventricle, 2 were isolated in the right ventricle, and 3 showed multiple foci. The prevalence of EIF was similar between younger and older patients, early and late gestational age at the time of sonographic examination, and optimal and suboptimal sonograms. Fetuses with EIF had significantly more congenital anomalies and other sonographic markers compared with fetuses without EIF.

CONCLUSIONS

We did not find any significant difference in the prevalence of EIF among the 4 different ethnic groups. The association between congenital anomalies and other sonographic markers should be studied further.

Is testing for cytomegalovirus and cystic fibrosis indicated in members of a nonwhite pregnant population in whom the fetus has an echogenic bowel?

The purpose of this study was to determine whether testing for cystic fibrosis (CF) and cytomegalovirus (CMV) infection is necessary in African-American and Hispanic gravidas in whom the fetus had an echogenic bowel. This retrospective study consisted of only African American and Hispanic patients in whom the fetus had an echogenic bowel, referred to the Maternal and Fetal Medicine unit at New Jersey Medical School for a specialized ultrasound, between June 30, 2004, and March 31, 2005. Sixty-five patients met the inclusion criteria for our study. Maternal serum testing for CF was done in 32 patients and all newborns were screened for the disease. There were no positive results for CF. CMV serology was tested in 38 patients and there were no cases of acute congenital CMV infection. In our population of 65 patients, there was one intrauterine growth restricted (IUGR) fetus and five intrauterine fetal demise (IUFD). Although all patients who were tested for CMV infection tested negative, the true incidence in our selected population may be underestimated because some of our patients were not tested. There were no cases of congenital CMV infection and all newborn screening tests for CF were negative. Prenatal diagnosis of fetal echogenic bowel was associated with a 7.6% incidence of IUFD and 1.6% incidence of IUGR.

[Relationship of phenotype with type of deletion of dystrophin gene]

OBJECTIVE

To detect the distribution characteristics of dystrophin gene deletions in the northeastern of China and the relationship of severity with type of deletion.

METHODS

To screen deletion distribution of 124 DMD/BMD patients via multiplex PCR, male high-risk fetuses were detected deletion by the same method.

RESULTS

The deletion frequency was 49%. Deletions located in the regions of exons 45 - 53 and exons 8 - 19 were 41 (67%) and 13 (21%) cases respectively, and in 5 (8%) cases deletions were scattered over both regions, still 2 cases (3%) were checked up deletions lying in exons 34 and 43; there were 9 cases of in-frame deletions and 49 frameshift mutations in all deletions; of 30 high-risk fetuses 10 male ones were screened deletions, who had the same deletion-segments as their probands.

CONCLUSIONS

The distribution of dystrophin gene deletions in the northeastern of China cluster mainly in two hot-spots, neighboring regions of exon 8 might be a real deletion "hot spot" in this region; the phenotype is associated with the type of gene deletion, the phenotype is BMD when in-frame deletions occur; severe DMD when frameshift mutations occur. Multiplex PCR method provides the short-cuts for detecting patients and making prenatal gene diagnosis.

Neonatal lupus erythematosus: a review of the racial differences and similarities in clinical, serological and immunogenetic features of Japanese versus Caucasian patients

There has been tremendous interest in neonatal lupus erythematosus (NLE) since the reports of anti-Ro/SSA antibodies as a diagnostic marker. Recent studies, including ours, have revealed racial differences as well as similarities in the clinical features and immunogenetic backgrounds of Japanese and Caucasian patients with NLE. The frequency of photosensitivity and subacute cutaneous LE lesions is not high in Japanese infants with NLE, which is in sharp contrast to their Caucasian American counterparts. The majority of Japanese infants with NLE develop annular, erythematous or edematous lesions which have also been reported in association with Sjögren's syndrome. The frequency of isolated congenital heart block (CHB) is about 50% in Japanese anti-Ro/SSA positive neonatal lupus infants; this is similar to the frequency among Caucasians. The HLA-DR3 phenotype, which is found in the great majority of Caucasian mothers of NLE infants, is absent in Japanese mothers. Finally, both Japanese and Caucasian children with CHB are often identical to their mothers in their alleles of HLA-DRB1, DQA1 and DQB1 loci.

Ethnic variation in the prevalence of echogenic intracardiac foci and the association with Down syndrome

OBJECTIVE

To determine whether the prevalence of fetal echogenic intracardiac foci (EIF) differs according to maternal ethnicity.

METHODS

We performed a retrospective cohort study of all women undergoing second-trimester diagnostic ultrasound examination and amniocentesis at a prenatal diagnosis referral center from January 1 2000 to July 1 2003. Data were collected on the presence of EIF, gestational age at time of ultrasound scan, karyotype results, maternal age and ethnicity. Univariate and multivariate analyses of EIF, ethnicity and presence of aneuploidy were conducted.

RESULTS

Among the 7480 women qualifying for the study, EIF were found in 309 (4.1%). When maternal ethnicity was subdivided into Caucasian, African-American, Hispanic, Asian-American, Native American, Asian Indian, and Middle Eastern, the highest rates of EIF were found in fetuses of African-American (6.7%), Asian-American (6.9%), and Middle Eastern (8.1%) mothers compared to a rate of 3.3% in Caucasians (P < 0.001). In all ethnic groups except Hispanics, EIF was associated with an increased risk for Down syndrome (odds ratio range from 1.8 to 15.7).

CONCLUSIONS

African-American, Asian-American, and Middle Eastern patients are more likely than patients of other ethnicities to have a fetus with an EIF. Even controlling for ethnicity, fetuses with an EIF still have an increased risk for Down syndrome. As more data accumulate, the prevalence of EIF and its association with Down syndrome among different ethnic groups can be incorporated into patient counseling.

The frequency of the detection of fetal echogenic intracardiac foci with respect to maternal race

OBJECTIVE

To determine if there is a racial difference in the frequency of identification of echogenic intracardiac foci (EIF) seen sonographically in the hearts of second-trimester fetuses.

METHODS

Over a 2-month period (June 1998-August 1998), all fetuses scanned between 15 and 20 completed weeks' gestation were evaluated prospectively for the presence or absence of EIF. Pregnancies specifically referred for the presence of EIF were excluded. The sonographer performing the scan indicated maternal race as Asian, black, white, or (if maternal race was not clear) unknown. Maternal race, gestational age, and the presence or absence of EIF were prospectively documented. Follow-up of those fetuses with EIF was obtained from the referring physicians' offices. The groups were compared with respect to maternal race and presence or absence of EIF.

RESULTS

There were 46, 34, 400, and nine fetuses of the Asian, black, white, and unknown mothers, respectively. The mean gestational age +/- 1 SD at examination was 18.2 +/- 1.6, 17.5 +/- 1.4, 17.7 +/- 1.5, and 17.8 +/- 1.1 weeks, for the Asian, black, white, and unknown mothers, respectively. The incidence of sonographically detected EIF was 30.4, 5.9, 10.5 and 11.1% for the Asian, black, white, and unknown mothers, respectively, P = 0.001. In a multivariate logistic regression model, Asian mothers had an odds ratio of 3.8 (95% CI, 1.8, 7.6) for having a fetus identified as having EIF, as compared with white mothers.

CONCLUSIONS

The Asian patient is more likely than patients of other races to have a fetus with identified EIF. The counseling implications for Asian mothers undergoing midtrimester sonography when EIF is identified should be tempered, due to the increased frequency of EIF as a normal finding in the Asian population.

Prenatal testing for genetic disorders among Arabs

Since, at least in the near future, prenatal testing and abortion of affected fetuses will remain the main way of the prevention of genetic diseases, knowledge about the way of its acceptance in different cultures is important. The Israeli population includes two major groups: Jewish and Arabs, but while there is wide experience about the Jewish population and its attitude towards prenatal testing, little is known about the Arab population. This knowledge is particularly important, since genetic disorders are relatively frequent in the Arab world (Teebi and Farag, 1997). From 1992 to 1996, 816 prenatal tests were performed in our department on Arab women [143 chorionic villus sampling (CVS) procedures and 673 amniocenteses]. The indication for an early prenatal test was a high risk for a monogenic disorder in 140 out of the 146 tests performed (143 CVS procedures and three early amniocenteses). In 26 cases, the fetus was found to be affected and early abortion was chosen by the couple in 25 cases (96 per cent). The 670 late prenatal tests were done for various reasons including monogenic disorders (13 per cent), increased risk because of a previous child affected with Down syndrome or a neural tube defect (4.8 per cent), and an increased risk for a chromosomal aberration (78 per cent). In 31 cases of a late prenatal test, the fetus was found to be affected and only 21 couples (70 per cent) opted for an abortion. The major reason for this observation is probably related to religious and cultural factors. Since Arab women do not wish to have prenatal testing for only knowledge or reassurance, these factors should be taken into consideration during pre-amniocentesis counselling.

Second-trimester maternal urinary gonadotrophin peptide screening for fetal Down syndrome in Asian women

Maternal urinary gonadotrophin peptide (UGP) was recently found to be elevated in second-trimester Down syndrome pregnancies. There is controversy about its screening efficacy. Data in the Asian population are scanty. We measured the UGP levels in 29 Down syndrome pregnancies and 297 controls and expressed them as a ratio of the urine creatinine concentration. Median UGP MOM was elevated to 3.44 (95 per cent confidence interval 1.99-5.13) in cases, compared with controls. UGP values were widely scattered in cases and controls with extensive overlap such that only 35 per cent of Down syndrome cases were expected to be detected at a 5 per cent false-positive rate. The data of the present study and previous reports show that there is a wide variability of gestation-specific UGP median values. UGP alone does not appear to be an effective screening marker for fetal Down syndrome.

Prenatal testing for Down syndrome in the Jewish and non-Jewish populations in Israel

The present work evaluated the efficacy of a prenatal diagnosis program in which amniocentesis and chorionic villus sampling were offered free of charge to all pregnant women in Israel aged > or = 37 years. The number of Down syndrome (DS) live births that occurred during the period of the program (1978-92) was correlated to the prevalence of old maternal age (> 35 years) and the utilization of prenatal test in the Jewish and non-Jewish populations in 1990 and 1992. It was noted that in the Jewish population, there was a slight increase in the DS live birth rate, from 1.05 in 1978, to 1.37 DS cases/1,000 live births in 1987, which corresponded to an increase in the prevalence of older pregnant women, from 8.0% in 1978 to 14.8% in 1987. Thereafter, however, there was a continuous decline, to 0.71 DS cases/1,000 live births in 1992, as a result of increased acceptance of prenatal testing by women > or = 37 years (67%) and, recently, also by younger women (from 5.6% in 1990 to 14% in 1992). In the non-Jewish population, there has been a very low acceptance rate of prenatal testing (23.3-16.1% in women > or = 37 years and 0.36-0.63% in women < 37 years). As a result, a very low prenatal detection rate (8-16% of all DS cases) and a high prevalence of DS live births (1.4 cases/1,000 live births) were observed. We suggest that a unique genetic counseling approach is required in the non-Jewish population to improve prenatal DS prevention in Israel.

Population study of the risk of fetal death and its relationship to birthweight, gestational age, and race

With more than 20,000 fetal deaths occurring annually in the United States, accurate epidemiological data concerning fetal death offer the potential to develop interventions aimed at saving a considerable number of fetuses. Currently, fetal death rates are determined by dividing the number of deaths by total births. These raw death rates do not focus on cause or preventability, nor do they delineate the risk for a individual pregnancy or any specific gestational age. Using data from 747,033 births in Illinois from 1984 to 1988, we estimated the fetal death risk (FDR) according to fetal weight and gestational age expressed as a function of the number of remaining fetuses. This procedure permits the comparison of FDR across all weights (including fetuses with growth retardation and macrosomia) and gestational ages. In addition, we examined the effect of race on this analysis. Between 28 and 36 weeks' gestational age, white fetuses with mean weights have a constant risk of fetal death at 0.1/1000 remaining fetuses. The risk is two to three times greater for black fetuses. If the fetus has growth retardation or is appropriately grown beyond 37 weeks' gestational age, the FDR increases further, with black fetuses remaining at higher risk. These data attempt to quantify the risk of fetal death. They support the widely held belief that the risk of fetal death increases in the presence of intrauterine growth retardation, but they also demonstrate that the risk of fetal death for all fetuses, including those appropriately grown, increases exponentially after 37 weeks' gestational age.(ABSTRACT TRUNCATED AT 250 WORDS)

Population differences affect nonstress test reactivity

The nonstress test (NST) is the most widely used test of fetal well-being. Recently it has been suggested that race may play a role in NST reactivity. The objective of this research was to explore population variables in addition to race that may influence NST reactivity. Study subjects were 1263 black and 658 white women who underwent NST in the week preceding delivery at a tertiary facility. Retrospective analysis of data from a comprehensive database was conducted. It was found that the percentage of black women with a nonreactive NST was more than three times the percentage of white women, and that from 35 weeks' to 42 weeks' gestation there were significantly fewer reactive NSTs for blacks than for whites (P less than .05). Racial differences in NST results persisted in a logistic regression analysis controlling for several population variables including pregnancy complications and demographic and behavioral factors (odds ratio 3.81; 95% CI 3.03 to 4.78). Regression analysis also confirmed that gestational age, maternal education, epilepsy, and smoking significantly influenced NST reactivity. These results indicate that population differences in NST reactivity exist at our facility. Further prospective study of population determinants of NST reactivity is needed to determine how race, test indication, and other clinical, demographic, and behavioral variables should be used in interpretation of tests of fetal well-being. Standard criteria for NST testing may not be useful in all obstetrical populations.