Perinatal outcomes in inflammatory bowel disease.

OBJECTIVE: To determine whether inflammatory bowel disease (IBD) is associated with increased risk for adverse perinatal outcome. METHODS: A case-control study of 116 singleton pregnancies with IBD compared to 56,398 singleton controls delivered between 1986 and 2001. RESULTS: Patients with IBD were slightly older (32.8 vs. 30.6 years, p < 0.001), more likely to be Caucasian or Asian than Black or Latino (92% vs. 57%, p < 0.001) and have private health insurance (33% vs. 3%, p < 0.001). IBD was associated with an increased risk for labor induction (32% vs. 24%, p = 0.002), chorioamnionitis (7% vs. 3%, p = 0.04) and Cesarean section (32% vs. 22%, p = 0.007), but there were no differences in neonatal outcomes. Subgroup analysis demonstrated an increased risk for low birth weight (LBW) in the ulcerative colitis group vs. the Crohn's disease group (19% vs. 0%, p = 0.002). Patients with prior surgery for IBD had a lower incidence of LBW (0% vs. 12%, p = 0.03). Flares during pregnancy were associated with an increased risk for preterm delivery (27% vs. 8%, p = 0.02) and LBW (32% vs. 3%, p = 0.003). CONCLUSION: IBD was an independent risk factor for Cesarean section but there was no increase in adverse perinatal outcome. Crohn's disease, prior IBD surgery and quiescent disease were associated with a lower risk for LBW.

Are women who are Jehovah's Witnesses at risk of maternal death?

OBJECTIVE: The purpose of this study was to determine the rates of obstetric hemorrhage and maternal mortality in women who are Jehovah's Witnesses and to evaluate a protocol that uses erythropoietin to optimize the red blood cell mass before delivery. STUDY DESIGN: Obstetric outcomes were described for all of the women who were Jehovah's Witnesses and who delivered at Mount Sinai Medical Center during an 11-year period. The risk of maternal death was compared with our general obstetric population during this interval. RESULTS: A total of 332 women who were Jehovah's Witnesses had 391 deliveries. An obstetric hemorrhage was experienced in 6% of this population. There were 2 maternal deaths among the women who were Jehovah's Witnesses, for a rate of 512 maternal deaths per 100,000 live births versus 12 maternal deaths per 100,000 live births (risk ratio, 44; 95% CI, 9-211). Erythropoietin was associated with a nonsignificant increase in hematocrit level. CONCLUSION: Women who are Jehovah's Witnesses are at a 44-fold increased risk of maternal death, which is due to obstetric hemorrhage. Patients should be counseled about this risk of death, and obstetric hemorrhage should be aggressively treated, including a rapid decision to proceed to hysterectomy when indicated.

Placental abruption and adverse perinatal outcomes.

CONTEXT: Pregnancies complicated by abruption result in increased frequency of perinatal death and decreased fetal size and gestational duration, yet the extent of placental separation and its effect on these adverse outcomes is unknown. OBJECTIVE: To assess the contribution of placental abruption and extent of placental separation to stillbirth, preterm delivery, and fetal growth restriction. DESIGN: Hospital-based, retrospective cohort study. SETTING: Mount Sinai Hospital, New York City, NY. PARTICIPANTS: A total of 53,371 pregnancies occurring in 40,789 women who were delivered of singleton births between 1986 and 1996. MAIN OUTCOME MEASURES: Risks and relative risks for stillbirth (>20 weeks), preterm delivery (<37 weeks), and fetal growth restriction (birth weight below 10th percentile for gestational age) in relation to abruption. RESULTS: The incidence of abruption was 1 % (n = 530). Abruption was associated with an 8.9-fold (95% confidence interval [CI], 6.0-13.0) adjusted relative risk (aRR) of stillbirth. Preterm birth proportions among women with and without abruption were 39.6% and 9.1 %, respectively, yielding an aRR of 3.9 (95% CI, 3.5-4.4). In the abruption group, 14.3% of neonates were growth restricted, compared with 8.1 % among all other births (aRR, 2.0; 95% CI, 1.5-2.4). Extent of placental separation had a profound effect on stillbirth (aRR for 75% separation, 31.5; 95% CI, 17.0-58.4), although evident only among those with at least 50% separation. However, the risk of preterm delivery was substantially increased even for mild abruptions (aRR for 25% separation, 5.5; 95% CI, 4.2-7.3). CONCLUSIONS: In this cohort, placental abruption had a profound impact on stillbirth, preterm delivery, and fetal growth restriction. The risk of stillbirth was dramatically increased for severe placental separation, but preterm delivery was common even among women with lesser degrees of placental separation.

Perinatal outcome in grand and great-grand multiparity: effects of parity on obstetric risk factors.

OBJECTIVE: We sought to compare obstetric and neonatal complications among great-grand multiparous, grand multiparous, and multiparous women. STUDY DESIGN: One hundred thirty-three great-grand multiparas, 314 grand multiparas, and 2195 multiparas who were delivered of their infants between 1988 and 1998 were selected for the study. To facilitate comparison, the patients were all >35 years old and had similar socioeconomic characteristics. RESULTS: The incidence of malpresentation at the time of delivery, maternal obesity, anemia, preterm delivery, and meconium-stained amniotic fluid increased with higher parity, whereas the rate of excessive weight gain and cesarean delivery decreased. Compared with grand multiparas, great-grand multiparas had significantly elevated risks for abnormal amounts of amniotic fluid, abruptio placentae, neonatal tachypnea, and malformations but lower rates of placenta previa (P <.05). The incidence of postpartum hemorrhage, preeclampsia, placenta previa, macrosomia, postdate pregnancy, and low Apgar scores was significantly higher in grand multiparas than in multiparas, whereas the proportion of induction, forceps delivery, and total labor complications was significantly lower than in the multiparous group (P <.05). Similar frequency of maternal diabetes, infection, uterine wall scar rupture, variations in fetal heart rate, fetal death, and neonatal mortality was found in the 3 groups. CONCLUSION: Both high-parity groups have their own risk factors, but the rate of some complications decreases with higher parity. In addition, perinatal mortality remains low in these patients, and therefore, under satisfactory socioeconomic and health care conditions, high parity should not be considered dangerous.

Risk factors for preterm birth subtypes.

To assess epidemiologic risk factors for preterm birth subcategories in an urban population, we undertook a study of 31,107 singleton livebirths that took place at Mount Sinai Hospital in New York City between 1986 and 1994. We subdivided the preterm births into preterm premature rupture of the membranes, preterm labor, and medically induced births. We obtained information regarding the preterm subtypes and their epidemiologic risk factors from a computerized perinatal database. Adjusted odds ratios showed an increased risk for all three preterm birth subtypes in women who were black (1.9 for preterm premature rupture of membranes, 2.1 for preterm labor, and 1.7 for medically induced births) or Hispanic (1.7 for preterm premature rupture of membranes, 1.9 for preterm labor, and 1.6 for medically induced births), those who had had a previous preterm birth (3.2 for preterm premature rupture of membranes, 4.5 for preterm labor, and 3.3 for medically induced births), those who began prenatal care after the first trimester ( 1.4 for preterm premature rupture of membranes, 1.3 for preterm labor, and 1.3 for medically induced births), women who had been exposed to diethylstilbestrol in utero (3.1 for preterm premature rupture of membranes, 4.1 for preterm labor, and 3.7 for medically induced births), patients with preexisting diabetes mellitus (2.2 for preterm premature rupture of membranes, 2.4 for preterm labor, and 9.5 for medically induced births), and those with antepartum bleeding (2.8 for preterm premature rupture of membranes, 3.6 for preterm labor, and 3.7 for medically induced births). Other sociodemographic, constitutional, life-style, and obstetrical characteristics differed across the groups. Variation in some of the risk factors among the preterm subtypes implies that epidemiologic assessment of the more specific outcomes would be advisable.

Prognostic factors and management in pregnancies complicated with severe kell alloimmunization: experiences of the last 13 years.

Because of the recent referral of an anti-Kell sensitized pregnant woman, whose fetus became severely anemic despite intensive antepartum surveillance, the prevalence and characteristics of fetal Kell isoimmunization were reviewed and analyzed. Cases with Kell and RhD alloimmunization requiring intrauterine intravascular transfusions (IUT) at the Mount Sinai Medical Center during the 13-year period ending March 1998 were compared. Thirty-six fetuses with RhD and 5 with Kell isoimmunization required IUTs. Lower fetal and neonatal hematocrit levels were observed in the RhD group. A significantly higher incidence of polyhydramnios was found among fetuses with Kell isoimmunization and the maternal serum titers were much lower than those in the RhD group. DeltaOD450 values did not reliably reflect the Kell sensitized fetus's condition. There were no intrauterine deaths or neonatal direct hyperbilirubinemia in the Kell group, and the hemolytic disease of the newborn was more severe in the RhD group. Although the course of the hemolytic disease in our cases of Kell isoimmunization showed a better prognosis than that in the RhD group, the importance of this condition should not be underestimated, and differences in the pathophysiology of Kell and RhD alloimmunization should be taken into consideration during the management of these cases.

Morbidity in the preterm infant with mature lung indices.

This study was designed to evaluate neonatal morbidity and mortality following preterm delivery in the setting of mature amniotic fluid pulmonary studies. We performed a retrospective analysis of all pregnancies resulting in preterm deliveries (< 37 weeks) from 1/1/88 to 5/31/92 in which there was a "mature" phospholipid profile, defined as positive phosphatidylglycerol (PG) or lecithin/sphyngomyelin (L/S) ratio > or = 2 determined within 1 week of delivery. Excluded were multiple gestations, diabetic pregnancies, and fetal or neonatal abnormalities involving the cardiovascular, renal, or pulmonary tract. Main outcome measures were incidence of significant neonatal morbidity, including respiratory distress requiring respiratory support, sepsis, patent ductus arteriosus, grade 3-4 intraventricular hemorrhage, necrotizing enterocolitis, retinopathy of prematurity, meningitis, and pneumonia. A total of 153 patients fulfilled the inclusion criteria. Mean (SD) gestational age at delivery and birth weight were 33.8 (2.1) weeks and 2298 (561) g, respectively. There were no neonatal deaths, but significant morbidity was present in 20% (31/153) of cases. The most common major neonatal complications were respiratory distress (12%) and suspected or documented sepsis (16%). Univariate analysis showed that frequency of major neonatal morbidity was related to gestational age at delivery (p < 0.001), birth weight (p < 0.001), Apgar score at 5 minutes < 7 (p = 0.008) and method of lung maturity assessment (complications were ore frequent when lung maturity was defined by L/S > or = 2 than by PG positivity) (p = 0.02). Multivariate analysis demonstrated a significant association between the presence of a neonatal complication and method of lung maturity assessment after adjustment for gestational age at delivery (p = 0.04). The incidence of major neonatal complications among preterm infants is high even in the presence of mature fetal lung studies; this incidence is related primarily to the gestational age at birth, and secondarily to the method of lung maturity testing (complications are less common in the presence of PG positivity than of L/S > or = 2).

Corticotropin-releasing factor and its binding protein: maternal serum levels in term and preterm deliveries.

OBJECTIVE: The primary objective of this investigation was to evaluate whether maternal serum corticotropin-releasing factor levels during pregnancy were predictive of spontaneous preterm delivery. STUDY DESIGN: Maternal serum levels of corticotropin-releasing factor and its binding protein were measured from 20 weeks of gestation in a cross-sectional study of 396 asymptomatic women at high risk for preterm delivery. RESULTS: Gestational age-specific corticotropin-releasing factor levels were not consistently or substantially increased for preterm compared with term deliveries, whether preterm delivery was due to preterm labor or preterm premature rupture of membranes. The binding protein for corticotropin-releasing factor did not vary according to gestational age until term, when it dropped substantially. CONCLUSION: Serum corticotropin-releasing factor levels do not appear to be an important predictor of preterm birth in asymptomatic patients who subsequently have either preterm labor or preterm premature rupture of membranes. Nevertheless, the drop in the corticotropin-releasing factor binding protein level at term suggests that the bioavailability of corticotropin-releasing factor increases as parturition approaches.

Risk factors for cryptorchidism: a nested case-control study.

A nested case-control study of cryptorchidism (i.e. undescended testicles) was undertaken as part of a hospital-based cohort study of 6699 singleton male neonates in New York City. Since some of the cryptorchid infants experienced spontaneous descent of their testes, separate analysis was performed for this third group of 'late descenders' (n=140). Cases (n=63) represented infants whose testes remained undescended at the one year assessment. Controls (n=219) represented the next male infant who was delivered immediately after an infant who was cryptorchid at birth. The only independent risk factors for cryptorchidism were Asian ethnic group (adjusted odds ratio (OR) = 3.90, 95% confidence interval (CI) = 1.22-12.41), swollen legs or feet during pregnancy (adjusted OR = 2.16, 95% CI = 1.15-4.04), a family history of cryptorchidism (adjusted OR = 4.32, 95% CI = 1.91-9.80), low birthweight (adjusted OR = 4.10, 95% CI = 1.39-12.08), and use of analgesics during pregnancy (adjusted OR = 1.93, 95% CI = 1.03-3.62). Multiple logistic regression analysis was also performed to identify those factors that were associated with late testicular descent. In this analysis the independent risk factors were black or Hispanic ethnicity (adjusted OR = 2.05, 95% CI = 1.09-3.83), a family history of cryptorchidism (adjusted OR = 4.25, 95% CI = 1.84-9.78), consumption of cola-containing drinks during the pregnancy (adjusted OR = 2.09, 95% CI = 1.10-3.99), a low birthweight delivery (adjusted OR = 9.78, 95% CI = 3.39-28.20), and preterm birth (adjusted OR = 4.01, 95% CI = 1.66-9.70).

The role of DDE and polychlorinated biphenyl levels in preterm birth.

Maternal serum levels of DDE and polychlorinated biphenyls (PCB) and their congeners were compared for 20 women who had a spontaneous preterm delivery and 20 matched women who had delivered at term at Mount Sinai Medical Center in New York between October 1990 and August 1993. Since no substantial case-control differences were evident, these findings do not indicate that increased DDE or PCB levels are associated with spontaneous preterm birth.

Prognostic factors for successful expectant management of ectopic pregnancy.

OBJECTIVE: To determine the independent ability of initial hCG titers, trend of hCG titers, and ultrasonographic findings in the prediction of successful expectant management in ectopic pregnancy (EP). DESIGN: Case-control study. SETTING: University hospital. PATIENTS: Sixty-seven patients with EP managed expectantly, 49 of whom (73%) had a spontaneous resolution, whereas 3 (5%) underwent medical treatment, and 15 (22%) eventually underwent surgical treatment. RESULTS: Univariate analysis showed that the initial hCG titer, the trend in hCG titers between first and second sample, and ultrasonographic visualization of absence of an ectopic gestational sac were significant predictors of a successful expectant management. Using receiver operating characteristic curve analysis, an hCG titer < 1,000 mIU/mL was chosen as the optimal cutoff for this prediction, identifying 88% of women destined to have spontaneous resolution of the EP. Multivariate analysis showed that both initial hCG titer and trend in hCG titers but not ultrasonographic visualization of an ectopic gestational sac were independent predictors of a successful or failed expectant management. CONCLUSION: Expectant management of EP is successful in the majority of patients with initial hCG titer < 1,000 mIU/mL.

Maternal and neonatal risk factors for cryptorchidism.

We assessed risk factors for cryptorchidism in a prospective hospital-based cohort study at Mount Sinai Hospital in New York City. We examined at birth 6,699 singleton male neonates who were delivered between October 1987 and October 1990. Follow-up examinations were undertaken at 3 months and 1 year for those diagnosed as cryptorchid at birth. We calculated prevalence ratios and adjusted odds ratios according to selected maternal and neonatal characteristics for those who remained cryptorchid at the 1-year assessment. We found elevated risks for maternal obesity [prevalence ratio = 2.42; 95% confidence interval (CI) = 1.11-5.27], for infants delivered by cesarean section (adjusted odds ratio = 2.17; 95% CI = 1.29-3.65), for low birthweight (adjusted odds ratio = 2.29; 95% CI = 1.12-4.70), for preterm birth (adjusted odds ratio = 2.25; 95% CI = 1.16-4.35), and for infants with congenital malformations (prevalence ratio = 13.97; 95% CI = 1.27-26.67). We observed a seasonal effect, with a peak in births of cryptorchid infants during September through November and a smaller peak during the months of March through May. We found no evidence that young women, white women, or primiparas were at increased risk.

An estrogen receptor genetic polymorphism and the risk of primary and secondary recurrent spontaneous abortion.

OBJECTIVE: A case-control study was undertaken to assess the association between an estrogen receptor gene variant and the risk of recurrent spontaneous abortions. STUDY DESIGN: The frequency of the estrogen receptor gene variant in blood lymphocyte deoxyribonucleic acid and other selected maternal characteristics was compared among 60 primary recurrent aborters, 61 secondary recurrent aborters, and 43 women who had had at least two live births but no spontaneous abortions. RESULTS: No association was evident between the estrogen receptor gene variant and the risk of either primary or secondary recurrent abortion. There were data suggesting that primary recurrent aborters in particular were more likely to report a family history of recurrent abortion and a family history of breast cancer. CONCLUSIONS: These findings indicate that the estrogen receptor polymorphism is not a genetic marker for recurrent spontaneous abortions. Therefore, as suggested by previous investigations, this polymorphism appears to be a marker for breast cancer risk only among the subgroups who have had a history of repeated abortions.

Do uterine leiomyomas influence pregnancy outcome?

To evaluate the clinical significance of the presence, location, size, and number of uterine leiomyomas in pregnancy, a retrospective cohort study in which pregnancy complications and outcome of pregnant women with uterine myomas was undertaken by routine second trimester ultrasound examination. The case group consisted of 183 consecutive women with uterine myomas detected and followed during the years 1983-1989; the control group was made up of all pregnancies diagnosed and followed at the obstetric clinic during the period 1985-1987. The incidences of preterm delivery (less than 37 weeks), preterm premature rupture of membranes, in utero growth retardation (less than 5th percentile), placental abruptio, placenta previa, postpartum hemorrhage (more than 500 cc), and retained placenta were not significantly increased in the group of women with myomas compared with the general population. However, cesarean sections were more common in women with myomas (23 vs 12%; P < 0.001). Within the group of women with myomas, the incidence of cesarean section was not different in cases with multiple rather than solitary myomas, but it was significantly higher in cases of lower uterine segment compared with fundal myomas (39 vs 18%; P < 0.01) and when the mean diameter of the myoma was greater than 5 cm (35 vs 17%; P = 0.01). Stepwise logistic regression analysis showed that both myoma location and size were independent predictors of the odds of cesarean section.

Low concentrations of vaginal fetal fibronectin as a predictor of deliveries occurring after 41 weeks.

OBJECTIVE: This study sought to determine whether low concentrations of fetal fibronectin in the cervical and vaginal secretions of patients at 39 weeks' gestation predicted pregnancies progressing beyond 41 weeks' gestation. STUDY DESIGN: A retrospective cohort study was undertaken using cervical and vaginal samples collected from 75 consenting patients during the thirty-ninth week of gestation. Levels of fetal fibronectin were measured by immunoassay. Demographic, obstetric, neonatal, and laboratory data were analyzed by Fisher's exact test, Student t test or Wilcoxon's rank-sum test, multiple logistic regression, and receiver-operating characteristic curve analysis. RESULTS: There was a 35.5-fold increase in vaginal fetal fibronectin concentrations among patients delivered at < 41 weeks compared with those delivered at > or = 41 weeks. The receiver-operating characteristic curve analysis indicated that the optimal fetal fibronectin predictor of prolonged pregnancies was a vaginal fetal fibronectin value < 60 ng/ml present between 39 weeks 0 days and 39 weeks 6 days' gestation (sensitivity 95.7%, 95% confidence interval 87.3% to 100.0%; specificity 44.2%, 95% confidence interval 30.7% to 57.7%; positive and negative predictive values 43.1% [95% confidence interval 29.5% to 56.7%] and 95.8% [95% confidence interval 87.8% to 100.0%], respectively). The relative risk for a prolonged pregnancy resulting from a vaginal fetal fibronectin value < 60 ng/ml was 10.4 (1.5 to 72.4). Among patients with a vaginal fetal fibronectin value > or = 60 ng/ml, 80.8% were delivered within 1 week and 92.3% within 10 days of sampling. In contrast, among patients with vaginal fetal fibronectin value < 60 ng/ml 63.3% remained undelivered after 1 week. After parity and cervical dilation were controlled for, multiple logistic regression demonstrated that a vaginal fetal fibronectin value < 60 ng/ml was a significant independent predictor of pregnancies delivered at > or = 41 weeks (adjusted odds ratio 12.8 [95% confidence interval 1.5 to 107.2]). CONCLUSIONS: A vaginal fetal fibronectin value > or = 60 ng/ml at 39 weeks' gestation is predictive of delivery within 10 days, whereas values < 60 ng/ml identify 95% of pregnancies progressing past 41 weeks' gestation. This data may allow for the prediction of postdates pregnancies, thus facilitating appropriate obstetric interventions.

Risk factors for pulmonary hypoplasia in second-trimester premature rupture of membranes.

OBJECTIVE: Our purpose was to determine the independent contribution of gestational age at rupture of membranes, latency period, and severity of oligohydramnios to the prediction of pulmonary hypoplasia in patients with second-trimester premature rupture of membranes. STUDY DESIGN: All women with premature rupture of membranes at < 28 weeks diagnosed between January 1982 and December 1990 were managed conservatively with a consistent protocol until intrauterine death or spontaneous or induced delivery. The diagnosis of pulmonary hypoplasia was made by strict pathologic and radiographic criteria. RESULTS: A total of 63 patients fulfilled the inclusion criteria. Pulmonary hypoplasia was present in 15 cases: two of nine stillborns, 12 of 25 neonatal deaths, and one of 24 survivors. All fetuses with pulmonary hypoplasia had oligohydramnios. Univariate analysis showed that the occurrence of pulmonary hypoplasia was significantly associated with gestational age at premature rupture of membranes (p = 0.002), oligohydramnios during the latency period (p = 0.005), and duration of the latency period (p = 0.02). However, logistic regression analysis showed that only the first two variables were independent predictors of pulmonary hypoplasia. CONCLUSION: Gestational age at premature rupture of membranes and oligohydramnios are independent predictors of the occurrence of pulmonary hypoplasia.

Prevalence and natural history of cryptorchidism.

OBJECTIVE: A prospective hospital-based cohort study was conducted to determine the prevalence rates of cryptorchidism at birth, 3 months, and 1 year of age. DESIGN: A total of 6935 consecutive male neonates delivered at Mount Sinai Hospital in New York City between October 1987 and October 1990 were examined at birth for cryptorchidism. Standardized examination and classification criteria were used. Infants classified as cryptorchid at birth were reexamined at 3 months and 1 year after the expected date of delivery. RESULTS: Of 6935 neonates assessed at birth, 255 (3.7%) were found to be cryptorchid at birth. The rates were significantly elevated for low birth weight, preterm, small-for-gestational age, and twin neonates. The overall rate had declined to 1.0% by the 3-month assessment and 1.1% at the 1-year assessment. Although the rates at the 1-year assessment tended to be higher for low birth weight and preterm infants, no significant group differences were observed. CONCLUSIONS: Since the prevalence rates in this study are similar to those reported several decades ago, these data provide no evidence that the rate of cryptorchidism has increased either at birth or by 1 year of age. Furthermore, most testes that descend spontaneously do so within the first 3 months after the expected date of delivery.

Morbidity of failed labor in patients with prior cesarean section.

OBJECTIVE: The aim of our study was to determine whether the reported increased morbidity associated with failed attempted vaginal birth after cesarean section is attributable to the presence of a uterine scar alone or to labor preceding a cesarean section. STUDY DESIGN: Primiparous women (N = 237) who underwent repeat cesarean section after a failed trial of vaginal birth after cesarean section were retrospectively compared with 1582 nulliparous women who underwent a primary cesarean section after a failed trial of labor. RESULTS: There were no significant differences in maternal or neonatal morbidity between the two groups except for an increase in the prevalence of thin meconium in patients undergoing primary cesarean section. CONCLUSION: Our results suggest that the presence of a previous cesarean section scar does not increase the overall baseline morbidity associated with cesarean section after labor.

Racial differences in pre- and postmenopausal bone homeostasis: association with bone density.

The disparity in fracture incidence and bone mass in women of European (white) and African (black) ancestry is of unknown etiology. To determine if racial differences in bone mass reflected racial differences in the mechanisms of bone turnover underlying bone mineral loss, we measured serum osteocalcin, serum alkaline phosphatase, fasting urinary calcium and hydroxyproline excretion, 24 h urinary excretion of calcium and sodium, and dietary intakes of calcium and vitamin D in 263 healthy pre-, peri-, and postmenopausal white and black women. In addition, radial and spinal bone density were measured cross-sectionally for comparison with biochemical measures of bone turnover. The biochemical parameters thought to reflect bone resorption (fasting urinary calcium and hydroxyproline excretions) were lower in black than in white women throughout the age and menopausal stages studied. The parameters thought to reflect bone formation (alkaline phosphatase and osteocalcin), were similar in the two racial groups among the premenopausal women, but osteocalcin was significantly lower among the peri- and postmenopausal blacks. Cross sectionally measured radial bone density increased with age in premenopausal black women, but it did not change with age in the white premenopausal subjects, a statistically significant difference. In peri- and postmenopausal women radial density declined significantly with years after menopause in both racial groups, but the rate of decline was significantly slower in the black women. Lumbar bone density in premenopausal white and black women did not change with age. After menopause lumbar bone density declined significantly and similarly in both racial groups.(ABSTRACT TRUNCATED AT 250 WORDS)