Is maternal colonization with group B streptococci a risk factor for preeclampsia?

OBJECTIVE: To explore the association between maternal rectovaginal colonization with group B Streptococcus (GBS) and the outcome of preeclampsia, and to identify other factors such as maternal chocolate consumption that may be associated with preeclampsia on the Texas-Mexico border. STUDY DESIGN: A case-control study was conducted among 330 women who delivered at a teaching hospital in El Paso, Texas, during the time period April 2010 to April 2012. Preeclamptic cases (n = 165) and controls free of preeclampsia (n = 165) were matched by gestational age and date of delivery. Conditional logistic regression (with multiple imputation for missing data) was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) that were adjusted for maternal age and other factors. RESULTS: Cases (94.6%) and controls (97.0%) were predominantly Hispanic. GBS colonization was not associated with preeclampsia: adjusted OR = 1.73 (95% CI 0.63-4.74, p = 0.29). Maternal consumption of chocolate desserts once daily or more frequently as compared to < 7 times weekly was associated with a 76% reduction in the odds of preeclampsia: adjusted OR = 0.24 (95% CI 0.09-0.63, p = 0.004). CONCLUSION: Our study did not confirm the protective association between GBS and preeclampsia that was found in 2 existing state hospital datasets. Chocolate consumption during pregnancy was inversely associated with preeclampsia.

Fetal sex pairing and adverse perinatal outcomes in twin gestations.

PURPOSE: To assess the association between fetal sex pairing in twin pregnancies and adverse perinatal and infant outcomes. METHODS: A retrospective cohort study of 9770 infants from 4885 twin pregnancies delivered in 2007 was conducted with a statewide hospital discharge database for Texas. Log-binomial regression models based on generalized estimating equations were used to calculate relative risks (RR) and 95% confidence intervals (95% CI) for the following dichotomous outcomes: breech presentation, hospital mortality, intrauterine growth restriction (IUGR), low birth weight, prolonged length of stay (>4 days), receipt of mechanical ventilation, and respiratory distress syndrome (RDS). RESULTS: The sample was composed of 4918 females and 4852 males. An approximately equal number of infants were from a female-female pregnancy (n = 3270), mixed-sex pregnancy (n = 3296), and a male-male pregnancy (n = 3204). Twins of either sex from mixed-sex pairs were 45% less likely to die in the hospital compared with females from a female-female pregnancy (RR, 0.55, 95% CI, 0.31-0.98). Males from a male-male pair were 33% less likely than females from female-female pairs to experience IUGR (RR, 0.67; 95% CI, 0.53-0.83). The incidence of RDS was significantly increased in males from male-male twin pairs versus females from female-female pairs (RR, 1.21; 95% CI, 1.05-1.41). CONCLUSIONS: Male infants from male-male twin pairs were more likely to develop RDS and be placed on a ventilator but less likely to experience IUGR than female infants from female-female pairs.

Prevalence of gestational fasting and postload single dysglycemia in Mexican-American women and their relative significance in identifying carbohydrate intolerance.

This study investigated the prevalence of gestational dysglycemia in a largely Hispanic population in a U.S.-Mexico border city and the influence of single plasma glucose (PG) result on the identification of gestational carbohydrate intolerance. Gestational dysglycemia was studied in a largely Mexican-American population using retrospective data. Gestational diabetes (GDM), gestational impaired fasting glucose (GIFG), and gestational impaired glucose tolerance (GIGT) were identified with Carpenter-Coustan thresholds. Glucose challenge test result was abnormal in 32.7% of 18307 women screened; 47% of them had one or more dysglycemic results in the confirmatory oral glucose tolerance test (OGTT). The prevalence of GDM, GIFG, and GIGT in these women was 8.7, 2.2, and 4.5%, respectively. Fasting, 1-hour, 2-hour, and 3-hour PGs were elevated in 20.5, 28.5, 25.0, and 15.0% of OGTT, respectively (GIFG: 6.0%; 1-hour GIGT: 6.5%; 2-hour GIGT: 4.4%; and 3-hour GIGT: 3.1%). Twelve percent of OGTTs showed dysglycemia at 1 hour with normal 2-hour PG. Isolated dysglycemia, similar to GDM, is prevalent in Mexican-American women. The minimal impact of 3-hour PG supports a 2-hour OGTT. But our results question the use of an "OGTT protocol without a first-hour specimen."

Risk factors for a prolonged length of stay in women hospitalized for preeclampsia in Texas.

OBJECTIVES: To identify correlates of a prolonged length of stay (PLOS) in women hospitalized for preeclampsia/eclampsia in Texas, USA. METHODS: Statewide hospital data were obtained, and the records of women who were discharged in 2004 and/or 2005 with a principal discharge diagnosis of preeclampsia or eclampsia were extracted using ICD-9-CM codes. PLOS was defined as a stay greater than 5 days. Odds ratios (OR) for PLOS were calculated. Generalized estimating equations were used to account for a small group of women who were hospitalized multiple times during the study period for preeclampsia. A total of 21,203 records were analyzed. RESULTS: The crude incidence of PLOS was 17.5%. Advancing maternal age was positively associated with PLOS: for every 10-year increase, there was a 20% increase in the odds of PLOS (adjusted OR = 1.20,95% confidence interval (CI): 1.13, 1.28). The strongest risk factor for PLOS was the presence of renal disease: adjusted OR 5.81 (95% CI: 3.97, 8.50). Protective factors included Medicaid beneficiary status, and being admitted from the emergency department. CONCLUSIONS: The strongest correlate of PLOS in a large cohort of women hospitalized for preeclampsia was the presence of renal disease.

Multiple imputation for missing laboratory data: an example from infectious disease epidemiology.

PURPOSE: To present multiple imputation (MI) as an appropriate method to address missing values for a laboratory parameter (serum albumin) in an epidemiologic study. METHODS: A data set of patients who were hospitalized for invasive group A streptococcal infections was accessed. Age was the exposure of interest. The outcome was hospital mortality. Several variables, including serum albumin, were considered to be potential confounders. Of the 201 records, 91 had missing values for serum albumin. The MI procedure in SAS was used to perform 20 imputations of serum albumin by using a Markov chain Monte Carlo approach. Logistic regression was then performed on each of the 20 filled-in data sets, and the results were appropriately combined by using the MIANALYZE procedure. RESULTS: Age (> or = 55 years vs. 0-54 years) was not a risk factor for hospital mortality in the complete-case analysis (n = 110): adjusted odds ratio (OR) = 2.43 (95% confidence interval [CI]: 0.79-7.53). Age was a significant risk factor in the imputed data set (n = 201): adjusted OR = 3.08 (95% CI: 1.22-7.78). CONCLUSIONS: Epidemiologists frequently encounter data sets that contain missing values. Traditional missing data techniques such as the complete-subject analysis may lead to biased results. We have demonstrated the use of a novel technique, MI, to account for missing data.

Elevated antiphospholipid antibody titers and adverse pregnancy outcomes: analysis of a population-based hospital dataset.

BACKGROUND: The primary objective of this study was to determine if elevated antiphospholipid antibody titers were correlated with the presence of preeclampsia/eclampsia, systemic lupus erythematosus (SLE), placental insufficiency, and a prolonged length of stay (PLOS), in women who delivered throughout Florida, USA. METHODS: Cross-sectional analyses were conducted using a statewide hospital database. Prevalence odds ratios (OR) were calculated to quantify the association between elevated antiphospholipid antibody titers and four outcomes in 141,286 women who delivered in Florida in 2001. The possibility that the relationship between elevated antiphospholipid antibody titers and the outcomes of preeclampsia/eclampsia, placental insufficiency, and PLOS, may have been modified by the presence of SLE was evaluated in a multiple logistic regression model by creating a composite interaction term. RESULTS: Women with elevated antiphospholipid antibody titers (n = 88) were older, more likely to be of white race and not on Medicaid than women who did not have elevated antiphospholipid antibody titers. Women who had elevated antiphospholipid antibody titers had an increased adjusted odds ratio for preeclampsia and eclampsia, (OR = 2.93 p = 0.0015), SLE (OR = 61.24 p < 0.0001), placental insufficiency (OR = 4.58 p = 0.0003), and PLOS (OR = 3.93 p < 0.0001). Patients who had both an elevated antiphospholipid antibody titer and SLE were significantly more likely than the comparison group (women without an elevated titer who did not have SLE) to have the outcomes of preeclampsia, placental insufficiency and PLOS. CONCLUSION: This exploratory epidemiologic investigation found moderate to very strong associations between elevated antiphospholipid antibody titers and four important outcomes in a large sample of women.

Descriptive and clinical epidemiology of preeclampsia and eclampsia in Florida.

OBJECTIVE: To calculate preeclampsia/eclampsia rates for Florida and identify risk factors for prolonged length of stay (PLOS) among women hospitalized throughout Florida for preeclampsia/eclampsia and discharged in 2001. DESIGN: Analyses were performed using a statewide hospital discharge dataset from Florida. Hospital discharge rates per Florida female population and risk per 100 deliveries were calculated for women hospitalized for preeclampsia. Binomial regression was used to calculate relative risks (RR) of PLOS among 5495 women. Generalized estimating equations were used to account for nesting by facility. RESULTS: Non-Whites had higher preeclampsia discharge rates per 10,000 population than Whites in every age group. The overall risk of preeclampsia was 3.9 per 100 deliveries, with the highest risks in the youngest and oldest age groups. The strongest risk factor for PLOS was having a diagnosis of preeclampsia/eclampsia superimposed on pre-existing hypertension. These patients had 2.64 times the risk of PLOS than patients who had mild or unspecified preeclampsia (P value <.0001). Diabetics were also at a higher risk of PLOS (adjusted RR=1.26, P=.003). Women who were admitted from the emergency department were 26% less likely than women admitted from other sources to have PLOS (adjusted RR=.74, P=.01). For every 10-year increase in maternal age, there was a 23% increase in the risk of PLOS (adjusted RR=1.23, P<.0001). CONCLUSIONS: Advancing maternal age, Black race, diabetes, severe preeclampsia, and preeclampsia (or eclampsia) superimposed on existing hypertension increased the risk of PLOS, while being admitted from the emergency department was associated with a decreased risk of PLOS.