INTRODUCTION: Understanding patterns of diabetes prevalence and diabetes-related complications across pregnancies could inform chronic disease prevention efforts. We examined adverse birth outcomes by diabetes status among women with sequential, live singleton deliveries. METHODS: We used data from the 1998-2007 Massachusetts Pregnancy to Early Life Longitudinal Data System, a population-based cohort of deliveries. We restricted the sample to sets of parity 1 and 2 deliveries. We created 8 diabetes categories using gestational diabetes mellitus (GDM) and chronic diabetes mellitus (CDM) status for the 2 deliveries. Adverse outcomes included large for gestational age (LGA), macrosomia, preterm birth, and cesarean delivery. We computed prevalence estimates for each outcome by diabetes status. RESULTS: We identified 133,633 women with both parity 1 and 2 deliveries. Compared with women who had no diabetes in either pregnancy, women with GDM or CDM during any pregnancy had increased risk for adverse birth outcomes; the prevalence of adverse outcomes was higher in parity 1 deliveries among women with no diabetes in parity 1 and GDM in parity 2 (for LGA [8.5% vs 15.1%], macrosomia [9.7% vs. 14.9%], cesarean delivery [24.7% vs 31.3%], and preterm birth [7.7% vs 12.9%]); and higher in parity 2 deliveries among those with GDM in parity 1 and no diabetes in parity 2 (for LGA [12.3% vs 18.2%], macrosomia [12.3% vs 17.2%], and cesarean delivery [27.0% vs 37.9%]). CONCLUSIONS: Women with GDM during one of 2 sequential pregnancies had elevated risk for adverse outcomes in the unaffected pregnancy, whether the diabetes-affected pregnancy preceded or followed it.

OBJECTIVES: Women with gestational diabetes mellitus (GDM) may be able to reduce their risk of recurrent GDM and progression to type 2 diabetes mellitus through lifestyle change; however, there is limited population-based information on GDM recurrence rates. METHODS: We used data from a population of women delivering two sequential live singleton infants in Massachusetts (1998-2007) to estimate the prevalence of chronic diabetes mellitus (CDM) and GDM in parity one pregnancies and recurrence of GDM and progression from GDM to CDM in parity two pregnancies. We examined four diabetes classification approaches; birth certificate (BC) data alone, hospital discharge (HD) data alone, both sources hierarchically combined with a diagnosis of CDM from either source taking priority over a diagnosis of GDM, and both sources combined including only pregnancies with full agreement in diagnosis. Descriptive statistics were used to describe population characteristics, prevalence of CDM and GDM, and recurrence of diabetes in successive pregnancies. Diabetes classification agreement was assessed using the Kappa statistic. Associated maternal characteristics were examined through adjusted model-based t tests and Chi square tests. RESULTS: A total of 134,670 women with two sequential deliveries of parities one and two were identified. While there was only slight agreement on GDM classification across HD and BC records, estimates of GDM recurrence were fairly consistent; nearly half of women with GDM in their parity one pregnancy developed GDM in their subsequent pregnancy. While estimates of progression from GDM to CDM across sequential pregnancies were more variable, all approaches yielded estimates of ≤5 %. The development of either GDM or CDM following a parity one pregnancy with no diagnosis of diabetes was <3 % across approaches. Women with recurrent GDM were disproportionately older and foreign born. CONCLUSION: Recurrent GDM is a serious life course public health issue; the inter-pregnancy interval provides an important window for diabetes prevention.

OBJECTIVE: To estimate the percentage of large-for-gestational age (LGA) neonates associated with maternal overweight and obesity, excessive gestational weight gain, and gestational diabetes mellitus (GDM)-both individually and in combination-by race or ethnicity. METHODS: We analyzed 2004-2008 linked birth certificate and maternal hospital discharge data of live, singleton deliveries in Florida. We used multivariable logistic regression to assess the independent contributions of mother's prepregnancy body mass index (BMI), gestational weight gain, and GDM status on LGA (birth weight-for-gestational age 90th percentile or greater) risk by race and ethnicity while controlling for maternal age, nativity, and parity. We then calculated the adjusted population-attributable fraction of LGA neonates to each of these exposures. RESULTS: Large-for-gestational age prevalence was 5.7% among normal-weight women with adequate gestational weight gain and no GDM and 12.6%, 13.5% and 17.3% among women with BMIs of 25 or higher, excess gestational weight gain, and GDM, respectively. A reduction ranging between 46.8% in Asian and Pacific Islanders and 61.0% in non-Hispanic black women in LGA prevalence might result if women had none of the three exposures. For all race or ethnic groups, GDM contributed the least (2.0-8.0%), whereas excessive gestational weight gain contributed the most (33.3-37.7%) to LGA. CONCLUSION: Overweight and obesity, excessive gestational weight gain, and GDM all are associated with LGA; however, preventing excessive gestational weight gain has the greatest potential to reduce LGA risk.

Based on their higher risk of type 2 diabetes, non-Hispanic blacks (NHBs) would be expected to have higher gestational diabetes mellitus (GDM) risk compared to non-Hispanic whites (NHWs). However, previous studies have reported lower GDM risk in NHBs versus NHWs. We examined whether GDM risk was lower in NHBs and NHWs, and whether this disparity differed by age group. The cohort consisted of 462,296 live singleton births linked by birth certificate and hospital discharge data from 2004 to 2007 in Florida. Using multivariable regression models, we examined GDM risk stratified by age and adjusted for body mass index (BMI) and other covariates. Overall, NHBs had a lower prevalence of GDM (2.5 vs. 3.1 %, p < 0.01) and a higher proportion of preconception DM births (0.5 vs. 0.3 %, p ≤ 0.01) than NHWs. Among women in their teens (risk ratio 0.56, p < 0.01) and 20-29 years of age (risk ratio 0.85, p < 0.01), GDM risk was lower in NHBs than NHWs. These patterns did not change with adjustment for BMI and other covariates. Among women 30-39 years (risk ratio 1.18, p < 0.01) and ≥40 years (risk ratio 1.22, p < 0.01), GDM risk was higher in NHBs than NHWs, but risk was higher in NHWs after adjustment for BMI. Associations between BMI and GDM risk did not vary by race/ethnicity or age group. NHBs have lower risk of GDM than NHWs at younger ages, regardless of BMI. NHBs had higher risk than NHWs at older ages, largely due to racial/ethnic disparities in overweight/obesity at older ages.

OBJECTIVES: We calculated the racial/ethnic-specific percentages of gestational diabetes mellitus (GDM) attributable to overweight and obesity. METHODS: We analyzed 1 228 265 records of women aged 20 years or older with a live, singleton birth in California during 2007 to 2009. Using logistic regression, we estimated the magnitude of the association between prepregnancy body mass index and GDM and calculated the percentages of GDM attributable to overweight and obesity overall and by race/ethnicity. RESULTS: The overall estimated GDM prevalence ranged from 5.4% among White women to 11.9% among Asian/Pacific Islander women. The adjusted percentages of GDM deliveries attributable to overweight and obesity were 17.8% among Asians/Pacific Islander, 41.2% among White, 44.2% among Hispanic, 51.2% among Black, and 57.8% among American Indian women. Select Asian subgroups, such as Vietnamese (13.0%), Asian Indian (14.0%), and Filipino (14.2%), had the highest GDM prevalence, but the lowest percentage attributable to obesity. CONCLUSIONS: Elevated prepregnancy body mass index contributed to GDM in all racial/ethnic groups, which suggests that decreasing overweight and obesity among women of reproductive age could reduce GDM, associated delivery complications, and future risk of diabetes in both the mother and offspring.

The objectives are to report the estimated prevalence of pregnancy complications and adverse pregnancy outcomes in a defined population of Alaska Native women and also examine factors contributing to an intensive and successful collaboration between a tribal health center and the Centers for Disease Control and Prevention. Investigators abstracted medical record data from a random sample of singleton deliveries to residents of the study region occurring between 1997 and 2005. We used descriptive statistics to estimate the prevalence and 95 % confidence intervals of selected pregnancy complications and adverse pregnancy outcomes. Records were examined for 505 pregnancies ending in a singleton delivery to 469 women. Pregnancy complication rates were 5.9 % (95 % CI 4.0, 8.4) for gestational diabetes mellitus, 6.1 % (95 % CI 4.2, 8.6 %) for maternal chronic hypertension and 11.5 % (95 % CI 8.8, 14.6) for pregnancy associated hypertension, and 22.9 % (95 % CI 19.2-26.5 %) for anemia. The cesarean section rate was 5.5 % (95 % CI 3.5, 7.5) and 3.8 % (95 % CI 2.3, 5.8) of newborns weighed >4,500 g. Few previous studies reported pregnancy outcomes among Alaska Native women in a specific geographic region of Alaska and regarding the health needs in this population. We highlight components of our collaboration that contributed to the success of the study. Studies focusing on special populations such as Alaska Native women are feasible and can provide important information on health indicators at the local level.

OBJECTIVE: To examine the potential effects of prenatal smokeless tobacco use on selected birth outcomes. DESIGN: A population-based, case-control study using a retrospective medical record review. POPULATION: Singleton deliveries 1997-2005 to Alaska Native women residing in western Alaska. METHODS: Hospital discharge codes were used to identify potential case deliveries and a random control sample. Data on tobacco use and confirmation of pregnancy outcomes were abstracted from medical records for 1123 deliveries. Logistic regression was used to examine associations between tobacco use and pregnancy outcomes. Adjusted odds ratios (OR), 95% confidence intervals (95% CI), and p-values were calculated. MAIN OUTCOMES MEASURES: Preterm delivery, pregnancy-associated hypertension, and placental abruption. RESULTS: In unadjusted analysis, smokeless tobacco use was not significantly associated with preterm delivery (OR 1.44, 95% CI 0.97-2.15). After adjustment for parity, pre-pregnancy body mass index, and maternal age, the point estimate was attenuated and remained non-significant. No significant associations were observed between smokeless tobacco use and pregnancy-associated hypertension (adjusted OR 0.92, 95% CI 0.56-1.51) or placental abruption (adjusted OR 1.11, 95% CI 0.53-2.33). CONCLUSIONS: Prenatal smokeless tobacco use does not appear to reduce risk of pregnancy-associated hypertension or to substantially increase risk of abruption. An association between smokeless tobacco and preterm delivery could not be ruled out. Components in tobacco other than nicotine likely play a major role in decreased pre-eclampsia risk in smokers. Nicotine adversely affects fetal neurodevelopment and our results should not be construed to mean that smokeless tobacco use is safe during pregnancy.

INTRODUCTION: Gestational diabetes mellitus (GDM) affects 3% to 7% of pregnant women in the United States, and Asian, black, American Indian, and Hispanic women are at increased risk. Florida, the fourth most populous US state, has a high level of racial/ethnic diversity, providing the opportunity to examine variations in the contribution of maternal body mass index (BMI) status to GDM risk. The objective of this study was to estimate the race/ethnicity-specific percentage of GDM attributable to overweight and obesity in Florida. METHODS: We analyzed linked birth certificate and maternal hospital discharge data for live, singleton deliveries in Florida from 2004 through 2007. We used logistic regression to assess the independent contributions of women's prepregnancy BMI status to their GDM risk, by race/ethnicity, while controlling for maternal age and parity. We then calculated the adjusted population-attributable fraction of GDM cases attributable to overweight and obesity. RESULTS: The estimated GDM prevalence was 4.7% overall and ranged from 4.0% among non-Hispanic black women to 9.9% among Asian/Pacific Islander women. The probability of GDM increased with increasing BMI for all racial/ethnic groups. The fraction of GDM cases attributable to overweight and obesity was 41.1% overall, 15.1% among Asians/Pacific Islanders, 39.1% among Hispanics, 41.2% among non-Hispanic whites, 50.4% among non-Hispanic blacks, and 52.8% among American Indians. CONCLUSION: Although non-Hispanic black and American Indian women may benefit the most from prepregnancy reduction in obesity, interventions other than obesity prevention may be needed for women from other racial/ethnic groups.

BACKGROUND: While evidence on the association between oral contraceptive (OC) use and breast cancer generally suggests little or no increased risk, the question of whether breast cancer risk varies by OC formulation remains controversial. Few studies have examined this issue because large samples and extensive OC histories are required. STUDY DESIGN: We used data from a multicenter, population-based, case-control investigation. Women aged 35-64 years were interviewed. To explore the association between OC formulation and breast cancer risk, we used conditional logistic regression to derive adjusted odds ratios, and we used likelihood ratio tests for heterogeneity to assess whether breast cancer risk varied by OC formulation. Key OC exposure variables were ever use, current or former use, duration of use and time since last use. To strengthen inferences about specific formulations, we restricted most analyses to the 2282 women with breast cancer and the 2424 women without breast cancer who reported no OC use or exclusive use of one OC. RESULTS: Thirty-eight formulations were reported by the 2674 women who used one OC; most OC formulations were used by only a few women. We conducted multivariable analyses on the 10 formulations that were each used by at least 50 women and conducted supplemental analyses on selected formulations of interest based on recent research. Breast cancer risk did not vary significantly by OC formulation, and no formulation was associated with a significantly increased breast cancer risk. CONCLUSIONS: These results add to the small body of literature on the relationship between OC formulation and breast cancer. Our data are reassuring in that, among women 35-64 years of age, we found no evidence that specific OC formulations increase breast cancer risk.

OBJECTIVE: To examine the effects of maternal prenatal smokeless tobacco use on infant birth size. DESIGN: A retrospective medical record review of 502 randomly selected deliveries. POPULATION: Singleton deliveries to Alaska Native women residing in a defined geographical region in western Alaska, 1997-2005. MATERIAL AND METHODS: A regional medical center's electronic records were used to identify singleton deliveries. Data on maternal tobacco exposure and pregnancy outcomes were abstracted from medical records. Logistic models were used to estimate adjusted mean birthweight, length, and head circumference for deliveries to women who used no tobacco (n=121), used smokeless tobacco (n=237), or smoked cigarettes (n=59). Differences in mean birthweight, length, and head circumference, 95% confidence intervals, and p-values were calculated using non-users as the reference group. MAIN OUTCOME MEASURES: Infant birthweight, crown-heel length, and head circumference. RESULTS: After adjustment for gestational age and other potential confounders, the mean birthweight of infants of smokeless tobacco users was reduced by 78g compared with that of infants of non-users (p=0.18), and by 331g in infants of smokers (p<0.01). No association was found between maternal smokeless tobacco use and infant length or infant head circumference. CONCLUSIONS: We found a modest but non-significant reduction in the birthweight of infants of smokeless tobacco users compared with infants of tobacco non-users. Because smokeless tobacco contains many toxic compounds that could affect other pregnancy outcomes, results of this study should not be construed to mean that smokeless tobacco use is safe during pregnancy.

OBJECTIVES: We calculated the percentage of gestational diabetes mellitus (GDM) attributable to overweight and obesity. METHODS: We analyzed 2004 through 2006 data from 7 states using the Pregnancy Risk Assessment Monitoring System linked to revised 2003 birth certificate information. We used logistic regression to estimate the magnitude of the association between prepregnancy body mass index (BMI) and GDM and calculated the percentage of GDM attributable to overweight and obesity. RESULTS: GDM prevalence rates by BMI category were as follows: underweight (13-18.4 kg/m(2)), 0.7%; normal weight (18.5-24.9 kg/m(2)), 2.3%; overweight (25-29.9 kg/m(2)), 4.8%; obese (30-34.9 kg/m(2)), 5.5%; and extremely obese (35-64.9 kg/m(2)), 11.5%. Percentages of GDM attributable to overweight, obesity, and extreme obesity were 15.4% (95% confidence interval [CI]=8.6, 22.2), 9.7% (95% CI=5.2, 14.3), and 21.1% (CI=15.2, 26.9), respectively. The overall population-attributable fraction was 46.2% (95% CI=36.1, 56.3). CONCLUSIONS: If all overweight and obese women (BMI of 25 kg/m(2) or above) had a GDM risk equal to that of normal weight women, nearly half of GDM cases could be prevented. Public health efforts to reduce prepregnancy BMI by promoting physical activity and healthy eating among women of reproductive age should be intensified.