Darios Getahun

Gestational diabetes in the United States: temporal trends 1989 through 2004

OBJECTIVE The objective of the study was to characterize trends in gestational diabetes (GDM) by maternal age, race, and geographic region in the United States. STUDY DESIGN The National Hospital Discharge Survey, comprised of births in the United States between 1989 and 2004 (weighted n = 58,922,266), was used to examine trends in GDM, based on an International Classification of Diseases, Ninth Revision, Clinical Modification code of 648.8. We examined temporal trends by comparing GDM rates in the earliest (1989-1990) vs most recent (2003-2004) biennial periods. Relative risks, quantifying racial disparity (black vs white) in GDM, were derived through logistic regression models after adjusting for confounders. These analyses were further stratified by maternal age and geographic region. RESULTS Prevalence rates of GDM increased from 1.9% in 1989-1990 to 4.2% in 2003-2004, a relative increase of 122% (95% confidence interval [CI] 120%, 124%). Among whites, GDM increased from 2.2% in 1989-1990 to 4.2% in 2003-2004 (relative increase of 94% [95% CI 91%, 96%]), and this was largely driven by an increase in the 25-34 year age group. In contrast, the largest relative increase in GDM (260% [95% CI 243%, 279%]) among blacks between 1989-1990 (0.6%) and 2003-2004 (2.1%) occurred to women aged younger than 25 years. The black-white disparity in GDM rates widened markedly among women aged younger than 35 years in the 1997-2004 periods. The largest relative increases were seen in the West (182% [95% CI 177%, 187%]) followed by the South and Northeast. The observed increase in GDM rates in the Northeast, Midwest, and South regions most likely is due to increase in GDM prevalence rates among blacks. CONCLUSION This study shows that the prevalence rate of GDM in the United States has increased dramatically between 1989 and 2004. The temporal increase and the widening black-white disparity in the rate of GDM deserves further investigation.

Previous cesarean delivery and risks of placenta previa and placental abruption.

OBJECTIVE: To examine the association between cesarean delivery and previa and abruption in subsequent pregnancies. METHODS: A retrospective cohort study of first 2 (n = 156,475) and first 3 (n = 31,102) consecutive singleton pregnancies using the 1989–1997 Missouri longitudinally linked data were performed. Relative risk (RR) was used to quantify the associations between cesarean delivery and risks of previa and abruption in subsequent pregnancies, after adjusting for several confounders. RESULTS: Rates of previa and abruption were 4.4 (n = 694) and 7.9 (n = 1,243) per 1,000 births, respectively. The pregnancy after a cesarean delivery was associated with increased risk of previa (0.63%) compared with a vaginal delivery (0.38%, RR 1.5, 95% confidence interval [CI] 1.3–1.8). Cesarean delivery in the first and second births conferred a two-fold increased risk of previa in the third pregnancy (RR 2.0, 95% CI 1.3–3.0) compared with first two vaginal deliveries. Women with a cesarean first birth were more likely to have an abruption in the second pregnancy (0.95%) compared with women who had a vaginal first birth (0.74%, RR 1.3, 95% CI 1.2–1.5). Two consecutive cesarean deliveries were associated with a 30% increased risk of abruption in the third pregnancy (RR 1.3, 95% CI 1.0–1.8). A second pregnancy within a year after a cesarean delivery was associated with increased risks of previa (RR 1.7, 95% CI 0.9–3.1) and abruption (RR 1.5, 95% CI 1.1–2.3). CONCLUSION: A cesarean first birth is associated with increased risks of previa and abruption in the second pregnancy. There is a dose–response pattern in the risk of previa, with increasing number of prior cesarean deliveries. A short interpregnancy interval is associated with increased risks of previa and abruption. LEVEL OF EVIDENCE: II-2

Prevalence of Extreme Obesity in a Multiethnic Cohort of Children and Adolescents

OBJECTIVE To estimate the prevalence of extreme obesity in a large, multiethnic contemporary cohort of children and adolescents. STUDY DESIGN In a cross-sectional study, measured weight and height were extracted from electronic medical records of 710,949 patients aged 2 to 19 years (87.8% of eligible patients) who were enrolled in an integrated prepaid health plan in 2007 and 2008. Prevalence of extreme obesity was defined as body mass index (BMI)-for-age>or=1.2 times 95th percentile or BMI>or=35 kg/m2. RESULTS Extreme obesity was observed in 7.3% of boys and 5.5% of girls. The prevalence peaked at 10 years of age in boys and at 12 years of age with a bimodal distribution in girls (second peak at 18 years; P value for sex x age interaction=.036). The prevalence of extreme obesity varied in ethnic/racial and age groups, with the highest prevalence in Hispanic boys (as high as 11.2%) and African-American girls (as high as 11.9%). CONCLUSION Extreme obesity in Southern California youth is frequently observed at relatively young ages. The shift toward extreme body weights is likely to cause an enormous burden of adverse health outcomes once these children and adolescents grow older.

Recurrence of Ischemic Placental Disease

OBJECTIVE: To test the hypothesis that the presence of preeclampsia, small for gestational age (SGA)-birth, and placental abruption in the first pregnancy confers increased risk in the second pregnancy. METHODS: A retrospective cohort study entailing a case–crossover analysis was performed based on women who had two consecutive singleton live births (n=154,810) between 1989 and 1997 in Missouri. Small for gestational age was defined as infants with birth weight below the 10th centile for gestational age. Risk and recurrence of ischemic placental disease was assessed from fitting logistic regression models after adjusting for several confounders. RESULTS: Preeclampsia in the first pregnancy was associated with significantly increased risk of preeclampsia (odds ratio 7.03, 95% confidence interval 6.51, 7.59), SGA (odds ratio 1.16, 95% confidence interval 1.06, 1.27), and placental abruption (odds ratio 1.90, 95% confidence interval 1.51, 2.38) in the second pregnancy. Similarly, women with SGA and abruption in the first pregnancy were associated with increased risks of all other conditions in the second pregnancy. CONCLUSION: Women with preeclampsia, SGA, and placental abruption in their first pregnancy—conditions that constitute ischemic placental disease—are at substantially increased risk of recurrence of any or all these conditions in their second pregnancy. Although causes of these conditions remain largely speculative, these entities may manifest through a common pathway of ischemic placental disease with significant risk of recurrence. LEVEL OF EVIDENCE: II

Placental Abruption in Term and Preterm Gestations: Evidence for Heterogeneity in Clinical Pathways

OBJECTIVE: To estimate the magnitude of associations of acute and chronic processes with abruption in preterm and term gestations. METHODS: A retrospective cohort study was performed using data on women that delivered singleton live births and stillbirths at 20 or more weeks of gestation in the United States, 1995–2002 (n = 30,378,902). Rates of 1) acute-inflammation–associated clinical conditions (premature rupture of membranes and intrauterine infection); 2) chronic processes associated with vascular dysfunction or chronic inflammation (chronic and pregnancy-induced hypertension, preexisting or gestational diabetes, small for gestational age, and maternal smoking); and 3) both acute and chronic processes, were examined among women with and without abruption. Rates were examined separately among preterm (< 37 weeks) and term births, with adjustment for confounders. Relative risk (RR) for aforementioned groups in relation to abruption was derived from multivariate logistic regression models after adjusting for potential confounders. RESULTS: At preterm gestation, the rates of acute-inflammation–associated conditions were higher among women with than without abruption (12.0% compared with 10.2%; RR 1.38, 95% confidence interval [CI] 1.34–1.42). At term, acute-inflammation–associated conditions were present in 4.2% and 3.3% of births with and without abruption, respectively (RR 1.39, 95% CI 1.33–1.45). At preterm gestation, the rates of chronic processes were 43.9% and 30.0% among women with and without abruption, respectively (RR 1.87, 95% CI 1.85–1.90). At term, the corresponding rates of chronic processes were 41.0% and 22.7%, respectively (RR 2.37, 95% CI 2.34–2.41). Association between both acute and chronic processes and abruption are similar to those of acute-inflammation–associated conditions. CONCLUSION: Among women with placental abruption, conditions associated with acute inflammation are more prevalent at preterm than term gestations, whereas chronic processes are present throughout gestation. LEVEL OF EVIDENCE: II-2

Recent Trends in Asthma Hospitalization and Mortality in the United States

Objective. To study the recent trends in asthma hospitalization and mortality rates by age, gender, and race categories in the United States. Methods. The National Hospital Discharge Survey Database for the years 1995 to 2002 was used to examine trends in asthma hospitalization. An International Classification of Diseases Ninth Revision, Clinical Modification (ICD-9-CM) code of 493.0 was used to identify primary hospitalization for asthma. Hospitalization rates were estimated using U.S. Census Bureau population estimates as denominators. Mortality data was obtained from the Center for Disease Control and Prevention Mortality Database. Death from asthma was identified using ICD-9-CM codes (493.0) for the years between 1995 and 1998 and ICD-10 codes (J45–J45.9) for 1999 and afterwards. Asthma hospitalization and mortality rates were estimated per 10,000 and per 100,000 populations, respectively. Crude relative risks (RR) were estimated to compare risks between various groups. Results. During the study period the age-adjusted asthma hospitalization rate decreased by 16.3% among white females (from 13.4/10,000 in 1995–1996 to 11.2/10,000 in 2001–2002), and by 7% (from 8.14/10,000 in 1995–1996 to 7.56/10,000 in 2001–2002) among white males. Among blacks the decrease in hospitalization rate was by 13.9% (from 38.18/10,000 in 1995–1996 to 32.86/10,000 in 2001–2002) in males and by 14.4% (from 40.21/10,000 in 1995–1996 to 34.42/10,000 in 2001–2002) in females. A narrowing of the black to white disparity in asthma hospitalization rate was noted for children younger than 10 years of age. On the other hand, the racial disparity among subjects 10 years and older narrowed until 2000 but has started to widen since then. The overall decrease in asthma mortality rate was evident for the age group ≥ 5, but remained unchanged for the age group less than five. The age adjusted asthma mortality rate has also decreased by 22.2% in blacks (from 3.33/100,000 in 1995 to 2.59/100,000 in 2001) and by 38.4% in whites (from 1.26/100,000 in 1995 to 0.78/100,000 in 2001). Conclusion. This study confirms that both asthma hospitalization and mortality rates decreased during the study period and the black to white racial disparity in asthma hospitalization has narrowed for children younger than 10 years of age. For those subjects 10 years and older the racial disparity in hospitalizations narrowed until 2000 but started to widen since then. The widening racial gap in adults is disconcerting and needs further observation to assess its persistence.

Gestational diabetes: risk of recurrence in subsequent pregnancies

OBJECTIVE We sought to examine the recurrence risk of gestational diabetes mellitus (GDM) in a subsequent pregnancy and determine whether recurrence risk is modified by race/ethnicity. STUDY DESIGN We used the Kaiser Permanente Southern California longitudinally linked records (1991-2008) to study women with first 2 (n = 65,132) and first 3 (n = 13,096) singleton pregnancies. Adjusted odds ratios (ORs) were used to estimate the magnitude of recurrence. RESULTS Risks of GDM in the second pregnancy among women with and without previous GDM were 41.3% and 4.2%, respectively (OR, 13.2; 95% confidence interval, 12.0-14.6). The recurrence risk of GDM in the third pregnancy was stronger when women had GDM in both prior pregnancies (OR, 25.9; 95% confidence interval, 17.4-38.4). Hispanics and Asian/Pacific Islanders have higher risks of recurrence. CONCLUSION A pregnancy complicated by GDM is at increased risk for subsequent GDM. The magnitude of risk increases with the number of prior episodes of GDM. These recurrence risks also showed heterogeneity by race-ethnicity.

Elective induction of labor at term compared with expectant management: maternal and neonatal outcomes.

OBJECTIVE: To test the association of elective induction of labor at term compared with expectant management and maternal and neonatal outcomes. METHODS: This was a retrospective cohort study of all deliveries without prior cesarean delivery in California in 2006 using linked hospital discharge and vital statistics data. We compared elective induction at each term gestational age (37–40 weeks) as defined by The Joint Commission with expectant management in vertex, nonanomalous, singleton deliveries. We used multivariable logistic regression to test the association of elective induction and cesarean delivery, operative vaginal delivery, maternal third- or fourth-degree lacerations, perinatal death, neonatal intensive care unit admission, respiratory distress, shoulder dystocia, hyperbilirubinemia, and macrosomia (birth weight greater than 4,000 g) at each gestational week, stratified by parity. RESULTS: The cesarean delivery rate was 16%, perinatal mortality was 0.2%, and neonatal intensive care unit admission was 6.2% (N=362,154). The odds of cesarean delivery were lower among women with elective induction compared with expectant management across all gestational ages and parity (37 weeks [odds ratio (OR) 0.44, 95% confidence interval (CI) 0.34–0.57], 38 weeks [OR 0.43, 95% CI 0.38–0.50], 39 weeks [OR 0.46, 95% CI 0.41–0.52], 40 weeks [OR 0.57, CI 0.50–0.65]). Elective induction was not associated with increased odds of severe lacerations, operative vaginal delivery, perinatal death, neonatal intensive care unit admission, respiratory distress, shoulder dystocia, or macrosomia at any term gestational age. Elective induction was associated with increased odds of hyperbilirubinemia at 37 and 38 weeks of gestation and shoulder dystocia at 39 weeks of gestation. CONCLUSION: Elective induction of labor is associated with decreased odds of cesarean delivery when compared with expectant management. LEVEL OF EVIDENCE: II

Maternal and obstetric risk factors for sudden infant death syndrome in the United States.

OBJECTIVE: The objectives of this study were to 1) study the incidence of sudden infant death syndrome (SIDS) among singleton births in the United States and 2) identify maternal and obstetric risk factors for SIDS. METHODS: A cohort of all live births in the United States from 1995 to 1998, formed the source population (n = 15,627,404). The data were obtained from the National Centers for Health Statistics Linked Births and Infant Deaths File. A nested case-control study was used to examine risk factors for SIDS. From this birth cohort, all SIDS deaths (n = 12,404) were first identified (case group). From the remaining non-SIDS births, a 4-fold larger sample (n = 49,616) was randomly selected as a control group. RESULTS: The overall incidence of SIDS was 81.7 per 100,000 live births. More mothers in the case group than in the control group were reported to have placenta previa (odds ratio [OR]: 1.70; 95% confidence interval [CI] 1.24, 2.33), abruptio placentae (OR 1.57; 95% CI 1.24, 1.98), premature rupture of membranes (OR 1.48; 95% CI 1.33, 1.66), or small for gestational age (OR 1.40; 95% CI 1.30, 1.50 for the 10th percentile). SIDS cases were also more likely to be male. Mothers of cases were more likely to be younger, less educated, and nonwhite, and more of them smoked during pregnancy and did not attend prenatal care. CONCLUSION: This analysis confirms the importance of several well known demographic and lifestyle risk factors for SIDS. In addition, placental abnormalities were risk factors for SIDS. LEVEL OF EVIDENCE: II-2

Racial and ethnic disparities in the trends in primary cesarean delivery based on indications

OBJECTIVE To examine trends in primary cesarean deliveries by indications and race/ethnicity. STUDY DESIGN We examined temporal trends in primary cesarean deliveries from 1991 through 2008 among singleton births (n = 540,953) in Kaiser Permanente Southern California hospitals using information from maternal hospitalizations and infant birth certificates. In addition, relative increases and 95% confidence intervals (CIs) were used to estimate differences in primary cesarean section rates by indication for the earliest (1991-1992) and most recent (2007-2008) periods. Racial/ethnic disparities in primary cesarean deliveries were examined by comparing the relative risks from multiple logistic regression models. RESULTS The rate of primary cesarean section among white, African American, Hispanic, and Asian/Pacific Islander women increased by 61.6%, 64.1%, 62.4%, and 70.2%, respectively, between 1991 and 2008. In comparison to the primary cesarean section rate for white women, the rate was 25% (95% confidence interval [CI], 22-29%) higher for African American women, 19% (95% CI, 16-23%) higher for Asian/Pacific Islander women, but 14% (95% CI, 13-16%) lower for Hispanic women. After adjustment for confounding factors, primary cesarean section rates remained significantly higher for African American women but lower for Hispanic women compared with white women. Indication subtypes-specific rates of primary cesarean section varied markedly across race/ethnicity. CONCLUSION We found that the overall primary cesarean section rate has increased over time. In addition, there is a wide variability in rate of indications for primary cesarean section by race/ethnicity.