Rita W. Driggers

The impact of pre-pregnancy body mass index on the risk of gestational diabetes

Objective: To evaluate the effect of pre-pregnancy body mass index (BMI) on the risk of developing gestational diabetes mellitus (GDM) in a large unselected population. Methods: We performed a case control study using data collected in The Consortium on Safe Labor database. The association between BMI and GDM was evaluated both using BMI weight categories adopted by the National Institute of Health, and separately using BMI as a continuous variable. Multiple logistic regression analyses were used to evaluate the effects of BMI, age, ethnicity, parity, chronic hypertension and antenatal steroid use on the risk of GDM. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to approximate relative risks of GDM. A p value of <0.05 was considered significant. Results: After controlling for other factors, the risk of GDM increased with an increasing BMI across all weight categories. For each 1 kg/m2 increase of BMI the OR of developing GDM was 1.08 (95% CI 1.08–1.09) and for each 5 kg/m2 increase, the OR was 1.48 (95% CI 1.45–1.51). Conclusions: GDM is a multifactorial disorder and pre-pregnancy BMI plays an important role in that risk. Modest changes in pre-pregnancy BMI may decrease the risk of GDM substantially.

Asymmetric large for gestational age newborns in pregnancies complicated by diabetes mellitus: is maternal obesity a culprit?

Objective: Evaluate the association between body mass index (BMI) and the delivery of an asymmetrically large for gestational age (A-LGA) newborn in women with diabetes. Methods: Retrospective analysis of 306 pregnancies complicated by Type 1 and 55 by Type 2 diabetes. Results: The prevalence of Type 1 and Type 2 diabetics delivering large for gestational age (LGA) infants was 42% and 49%, respectively. Of these 49% and 55% were A-LGA, respectively. Pre-pregnancy BMI was not associated with increased odds of delivering an A-LGA newborn in women with Type 1 or 2 diabetes. However, in Type 1 diabetics, each one-pound increase in maternal weight during pregnancy resulted in 4% increased odds of delivering an A-LGA newborn. For Type 2 diabetics, the odds of delivering an A-LGA infant was decreased by 10% for each 0.1 unit/kg increase in insulin dose. Conclusion: Although there is a known association between obesity and LGA in women with diabetes, we found that overweight and obese women with Type 1 or Type 2 diabetes do not have increased odds of delivering an A-LGA newborn. However, insulin dose in Type 2 diabetes and maternal weight gain in Type 1 diabetes were significantly associated with the odds of delivering an A-LGA neonate.

Timing and consequences of early term and late term deliveries

Abstract Objective: To examine the timing of elective delivery and neonatal intensive care unit (NICU) utilization of electively delivered infants from 2008to 2011. Methods: Analysis included 42 290 women with singleton gestation enrolled in a pregnancy education program, reporting uncomplicated pregnancies with elective labor induction (ELI) (n = 27 677) or scheduled cesarean delivery (SCD) (n = 14 613) at 37.0–41.9 weeks’ gestation. Data were grouped by type and week of delivery (37.0–37.9, 38.0–38.9, and 39.0–41.9 weeks). ELI and SCD for each week of delivery from 2008 to 2011 and nursery utilization by delivery week were compared. Results: During the 2008–2011 timeframe, a shift in timing of ELI and SCD toward ≥39.0 weeks was observed. In 2008, 80.9% of ELI occurred at ≥39.0 weeks versus 92.6% in 2011 (p < 0.001). In 2008, 60.5% of SCD occurred at ≥39.0 weeks versus 78.1% in 2011 (p < 0.001). NICU admission and prolonged nursery stays were highest at 37.0–37.9 weeks for both groups. Conclusions: We observed a shift toward later gestational age at elective delivery from 2008 to 2011 and increased NICU utilization for neonates born at <39 weeks’ gestation.

Spontaneous labor curves in women with pregnancies complicated by diabetes.

Objective: To test the hypothesis that the first stage of labor will be longer in nulliparous and multiparous women with diabetes compared to non-diabetic counterparts. Methods: A retrospective analysis was performed from 228,668 deliveries between 2002–2008 from the Consortium of Safe Labor (National Institute of Child Health and Human Development, National Institutes of Health). Patients with spontaneous onset of labor from 37 0/7–41 6/7 weeks gestation were included (71,282) and classified as nulliparous or multiparous. Pregnancies were further subdivided regarding presence of preexisting diabetes (preDM) or gestational diabetes (GDM) and normal controls. Labor curves were created matching for body mass index (BMI) and neonatal birth weight. Statistical analysis was performed on descriptive variables using χ2 with significance designated as p < 0.05. Results: Among nulliparous patients, there were 118 women with preDM and 475 women with GDM; 25,771 patients served as normal controls. Among multiparous women, there were 311 with preDM, 1,079 with GDM and 43,528 in the control group. Although differences in dilatation rates were observed in nulliparous and multiparous women with and without diabetes, labor progression was similar between the subgroups when matched for maternal BMI and birth weight. Conclusions: Labor curves of women with preDM and GDM approximate those of non-diabetics, regardless of BMI, birth weight, or parity.

Fetal biometry: does patient ethnicity matter?

Abstract Objective: To determine if fetal biometry varies according to race. Methods: We performed a retrospective chart review of prenatal ultrasounds completed in our Perinatal Center from January 2009 to December 2010. Singleton pregnancies 17 to 22.9 weeks were included. Pregnancies complicated by IUGR, fetal anomalies, chronic maternal diseases, or dated by an ultrasound after the first trimester were excluded. Biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), and humerus length (HL) were compared between African Americans (AA), Caucasians, and Hispanics using ANOVA and Student t-test. Results: Included were 1327 AA, 147 Caucasian, and 86 Hispanic subjects. The AC was significantly smaller in AA than Caucasians (p = 0.008). There was no difference between AA and Caucasians in BPD, HC, FL, or HL. There were no differences between Hispanics and either Caucasians or AA in any of the biometries evaluated. Conclusions: A single fetal growth curve is not applicable across all ethnicities. AA fetuses have smaller AC then Caucasian fetuses from 17 to 22.9 weeks, which is typically the period when anatomic surveys are performed. Because AC contributes heavily to estimated fetal weight calculations, physicians may be over estimating growth restriction in AA patients. Ethnicity-specific fetal growth curves are indicated to limit unnecessary follow up.

Racial disparities in maternal and neonatal outcomes in HIV-1 positive mothers.

OBJECTIVE To compare obstetric and neonatal outcomes between human immunodeficiency virus (HIV) positive (HIV+) and HIV negative (HIV-) women and to determine if racial disparities exist among pregnancies complicated by HIV infection. STUDY DESIGN This was a retrospective analysis of data from the Consortium of Safe Labor between 2002 and 2008. Comparisons of obstetric morbidity, neonatal morbidity, and indications for cesarean delivery were examined. Included were singletons with documented HIV status, race, and antepartum admission. Chi-square, Fisher exact tests, and logistic regression were used for statistical analysis. RESULTS Included were 178,972 patients (178,210 HIV-, 762 HIV+, 464 HIV+ black, 298 HIV+ nonblack). HIV+ women were more likely to have a cesarean delivery, preterm premature rupture of membranes, another sexually transmitted infection, and delivery at an earlier gestational age. Obstetric outcomes were similar between HIV+ black and HIV+ nonblack women. Neonates of HIV+ mothers had lower birth weights and higher rates of neonatal intensive care admissions. HIV+ black women had lower birth weight neonates than HIV+ nonblack women. CONCLUSION HIV+ women have higher rates of obstetric complications and deliver at an earlier gestational age than HIV- mothers. Lower birth weight was the only notable complication among HIV+ black women compared with HIV+ nonblack women.

Rates of recurrent preterm birth by maternal body habitus in women receiving 17α-hydroxyprogesterone caproate

Abstract Objective: To examine the influence of maternal pre-pregnancy body mass index (BMI) on the rates of recurrent spontaneous preterm birth (SPTB) in women receiving 17α-hydroxyprogesterone caproate (17P). Methods: Retrospective analysis of a cohort of 6253 women with a singleton gestation and prior SPTB enrolled in 17P home administration program between 16.0 and 26.9 weeks. Data were grouped by pre-pregnancy BMI (lean <18.5 kg/m2, normal 18.5–24.9 kg/m2, overweight 25–29.9 kg/m2 and obese ≥30.0 kg/m2). Delivery outcomes were compared using χ2 and Kruskal–Wallis tests with statistical significance set at p < 0.05. Results: SPTB<28 weeks was significantly lower in normal weight women. Rates of recurrent SPTB<37 weeks were highest in the group with BMI<18.5 kg/m2. Lean gravidas were younger, more likely to smoke, and less likely to be African–American than those with normal or increased BMI. In logistic regression, after controlling for race and prior preterm birth <28 weeks, the risk of SPTB<37 weeks decreased 2% for every additional 1 kg/m2 increase in BMI. Conclusions: Recurrent spontaneous preterm delivery<37 weeks in patients on 17P is more common in lean women (BMI<18.5 kg/m2), and less common in obese women (BMI ≥30 kg/m2) suggesting that the current recommended dosing of 17 P is adequate for women with higher BMI.

Accuracy of Clinically Estimated Fetal Weight in Pregnancies Complicated by Diabetes Mellitus and Obesity

OBJECTIVE To determine the accuracy of clinically estimated fetal weight (CEFW) in patients with gestational diabetes (GDM), pregestational diabetes (DM), and obesity. STUDY DESIGN This is a retrospective analysis of Consortium of Safe Labor data. Subjects were classified into six groups: DM, DM and obese, GDM, GDM and obese, nondiabetic obese, and controls. The mean difference between birth weight (BW) and CEFW, the percent of accurate CEFW (defined as < 10% difference), and the sensitivity for identifying BW > 4,000 g and > 4,500 g were calculated for each group. RESULTS The accuracy of CEFW in our population was 54.3 to 64.4% and was significantly lower in patients with DM and obesity and patients with obesity but not diabetes. When CEFW was analyzed in the >4,000-g and > 4,500-g groups, its accuracy was 20 to 51% and 14 to 40%, respectively. CEFW overestimated BW more commonly in GDM, obese GDM, and obese groups. The sensitivity of CEFW for diagnosing BW > 4,000 g or > 4,500 g was 19.6% and 9.6%, respectively, and it improved in pregnancies complicated by diabetes. CONCLUSION CEFW is a poor predictor of macrosomia in pregnancies complicated by obesity and diabetes.

Diabetes in Pregnancy

The increasing rate of obesity has led to a higher number of cases with diabetes during pregnancy. Recent studies describe a linear relationship between glycemia and fetal outcomes and suggest a need to adjust screening strategies and diagnostic criteria. Furthermore, the time period for treatment during pregnancy is limited and pharmacologic details on currently used treatments are limited. Insulin remains the standard therapy but is more burdensome than oral drugs and less favored by patients. Recently, oral hypoglycemics have gained popularity and are more commonly used for the treatment of gestational diabetes. However, recent pharmacokinetic studies suggest a need for dose adjustment of oral hypoglycemics to account for physiologic and metabolic changes during pregnancy. The chapter reviews available treatments and outlines therapeutic regimens for diabetes during pregnancy.

The 12th meeting of the Diabetes in Pregnancy Study Group of North America (DPSG-NA): introduction and overview

The Diabetes in Pregnancy Study Group of North America (DPSG-NA) held its 12th meeting April 1-2, 2011 in Washington DC. The meeting, which was co-hosted by the Washington Hospital Center and the University of Maryland School of Medicine focused on five broad themes: (i) the prevention of diabetes and its risk factors, such as obesity, in pregnancy; (ii) the appropriate use of pharmacotherapies for managing diabetes in pregnancy; (iii) optimal glycemic control; (iv) the value of nutrition, exercise and limiting weight gain during pregnancy and (v) the diagnosis and consequences of diabetic fetopathy. These proceedings reflect peer-reviewed papers of data presented at the meeting. Time also was allocated to discuss the perceived barriers to using the one-step, 75 g oral glucose tolerance test as the first-line approach to diagnosing gestational diabetes mellitus. Responses from a survey of participants on perceived barriers to adopting this method into widespread clinical practice are discussed.