Lucinda J. England

Trends in Pre-pregnancy Obesity in Nine States, 1993-2003

Objective: Pre‐pregnancy obesity poses risks to both pregnant women and their infants. This study used a large population‐based data source to examine trends, from 1993 through 2003, in the prevalence of pre‐pregnancy obesity among women who delivered live infants.

Infant Morbidity and Mortality Attributable to Prenatal Smoking in the U.S.

BACKGROUND Although prenatal smoking continues to decline, it remains one of the most prevalent preventable causes of infant morbidity and mortality in the U.S. PURPOSE The aim of this study was to estimate the proportion of preterm deliveries, term low birth weight deliveries, and infant deaths attributable to prenatal smoking. METHODS Associations were estimated for prenatal smoking and preterm deliveries, term low birth weight (<2500 g) deliveries, sudden infant death syndrome (SIDS), and preterm-related deaths among 3,352,756 singleton, live births using the U.S. Linked Birth/Infant Death Data Set, 2002 birth cohort. The 2002 data set is the most recent, in which 49 states used the same standardized smoking-related question on the birth certificate. Logistic regression models estimated ORs of prenatal smoking for each outcome, and the prenatal smoking population attributable fraction was calculated for each outcome. RESULTS Prenatal smoking (11.5% of all births) was significantly associated with very (AOR=1.5, 95% CI=1.4, 1.6); moderate (AOR=1.4, 95% CI=1.4, 1.4); and late (AOR=1.2, 95% CI=1.2, 1.3) preterm deliveries; term low birth weight deliveries (AOR=2.3, 95% CI=2.3, 2.5); SIDS (AOR=2.7, 95% CI=2.4, 3.0); and preterm-related deaths (AOR=1.5, 95% CI=1.4, 1.6). It was estimated that 5.3%-7.7% of preterm deliveries, 13.1%-19.0% of term low birth weight deliveries, 23.2%-33.6% of SIDS, and 5.0%-7.3% of preterm-related deaths were attributable to prenatal smoking. Assuming prenatal smoking rates continued to decline after 2002, these PAFs would be slightly lower for 2009 (4.4%-6.3% for preterm-related deaths, 20.2%-29.3% for SIDS deaths). CONCLUSIONS Despite recent declines in the prenatal smoking prevalence, prenatal smoking continues to cause a substantial number of infant deaths in the U.S.

Estimates of Nondisclosure of Cigarette Smoking Among Pregnant and Nonpregnant Women of Reproductive Age in the United States

Although clinic-based studies have used biochemical validation to estimate the percentage of pregnant women who deny smoking but are actually smokers, a population-based estimate of nondisclosure of smoking status in US pregnant women has not been calculated. The authors analyzed data from the 1999-2006 National Health and Nutrition Examination Survey and estimated the percentage of 994 pregnant and 3,203 nonpregnant women 20-44 years of age who did not report smoking but had serum cotinine levels that exceeded the defined cut point for active smoking (nondisclosure). Active smoking was defined as self-reporting smoking or having a serum cotinine concentration that exceeded the cut point for active smoking. Overall, 13.0% (95% confidence interval (CI): 8.8, 17.1) of pregnant women and 29.7% (95% CI: 27.3, 32.1) of nonpregnant women were active smokers. Nondisclosure was higher among pregnant active smokers (22.9%, 95% CI: 11.8, 34.6) than among nonpregnant smokers (9.2%, 95% CI: 7.1, 11.2). Among pregnant active smokers, nondisclosure was associated with younger age (20-24 years). Among nonpregnant active smokers, nondisclosure was associated with Mexican-American and non-Hispanic black race/ethnicity. Studies and surveillance systems that rely on self-reported smoking status are subject to underestimation of smoking prevalence, especially among pregnant women, and underreporting may vary by demographic characteristics.

Percentage of gestational diabetes mellitus attributable to overweight and obesity.

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.

Elevated levels of growth‐related hormones in autism and autism spectrum disorder

Objective  Children with autism are known to have larger head circumferences; whether they are above average in height and weight is less clear. Moreover, little is known about growth‐related hormone levels in children with autism. We investigated whether children with autism were taller and heavier, and whether they had higher levels of growth‐related hormones than control children did.

Nicotine and the Developing Human A Neglected Element in the Electronic Cigarette Debate

The elimination of cigarettes and other combusted tobacco products in the U.S. would prevent tens of millions of tobacco-related deaths. It has been suggested that the introduction of less harmful nicotine delivery devices, such as electronic cigarettes or other electronic nicotine delivery systems, will accelerate progress toward ending combustible cigarette use. However, careful consideration of the potential adverse health effects from nicotine itself is often absent from public health debates. Human and animal data support that nicotine exposure during periods of developmental vulnerability (fetal through adolescent stages) has multiple adverse health consequences, including impaired fetal brain and lung development, and altered development of cerebral cortex and hippocampus in adolescents. Measures to protect the health of pregnant women and children are needed and could include (1) strong prohibitions on marketing that increase youth uptake; (2) youth access laws similar to those in effect for other tobacco products; (3) appropriate health warnings for vulnerable populations; (4) packaging to prevent accidental poisonings; (5) protection of non-users from exposure to secondhand electronic cigarette aerosol; (6) pricing that helps minimize youth initiation and use; (7) regulations to reduce product addiction potential and appeal for youth; and (8) the age of legal sale.

Weight-Management Interventions for Pregnant or Postpartum Women

BACKGROUND A review of randomized controlled trials of weight-management interventions for pregnant or postpartum women was conducted to assess whether effective weight-management interventions exist for this population. METHODS The MEDLINE, EMBASE, PsycINFO, Sociological Abstracts, and CINAHL databases were searched, as well as the reference lists of relevant publications. English-language articles published between January 1985 and August 2007 that used a randomized controlled trial study design and incorporated a weight-related outcome measure were reviewed. All potentially relevant articles were reviewed separately, and final selections were based on consensus reached through discussion. RESULTS Three studies met the inclusion criteria, one conducted among pregnant women and two among postpartum women. The interventions addressed modifications in diet and exercise and included individual or group-counseling sessions combined with written and telephone correspondence or food and exercise diaries. In two studies, the weight-related outcome was significantly better in the intervention group than in the control group. The third study found a significant interaction between weight category and intervention group. In all studies, the refusal or attrition rates were high. CONCLUSIONS While these studies indicate that interventions can help pregnant and postpartum women manage their weight, many questions remain unanswered. Several research gaps for weight-management interventions in this important population have been identified.

Misclassification of Maternal Smoking Status and its Effects on an Epidemiologic Study of Pregnancy Outcomes

Reliance on self-reported smoking status among pregnant women can result in exposure misclassification. We used data from the Calcium for Preeclampsia Prevention trial, a randomized study of nulliparous women conducted from 1992 to 1995, to characterize tobacco exposure misclassification among women who reported at study enrollment that they had quit smoking. Urinary cotinine concentration was used to validate quit status, and factors associated with exposure misclassification and the effects of misclassification on associations between smoking and pregnancy outcomes were evaluated using logistic regression. Of 4,289 women enrolled, 508 were self-reported smokers and 771 were self-reported quitters. Of 737 self-reported quitters with a valid cotinine measurement, 21.6% had evidence of active smoking and were reclassified as smokers. Women who reported having quit smoking during pregnancy were more likely to be reclassified than women who reported quitting before pregnancy (p<.001). Among smokers, factors independently associated with misclassification of smoking status included fewer cigarettes smoked per day and fewer years smoked. After reclassification the odds ratio for a small-for-gestational-age birth among smokers decreased by 14%, and the smoking-related reduction in birth weight decreased by 15%. Effects of misclassification on the association with hypertensive disorders of pregnancy were present but less dramatic. In conclusion, use of self-reported smoking status collected at the time of study enrollment resulted in the introduction of bias into our study of smoking and pregnancy outcomes. The potential for this type of bias should be considered when conducting and interpreting epidemiologic studies of smoking and pregnancy outcomes.

Preventing type 2 diabetes: public health implications for women with a history of gestational diabetes mellitus.

There is now strong evidence that lifestyle modification can prevent or delay the development of type 2 diabetes mellitus in high-risk individuals. Women with gestational diabetes mellitus are at increased risk for type 2 diabetes and so are candidates for prevention programs. We review literature on type 2 diabetes risk in women with gestational diabetes, examine current recommendations for postpartum and long-term follow-up, and summarize findings from a 2007 expert-panel meeting. We found data to support that women with gestational diabetes have an increase in risk of type 2 diabetes comparable in magnitude with that of individuals with impaired glucose tolerance and/or impaired fasting glucose and that prevention interventions likely are effective in this population. Current recommendations from leading organizations on follow-up of women after delivery are conflicting and compliance is poor. Clinicians and public health workers face numerous challenges in developing intervention strategies for this population. Translation research will be critical in addressing this important public health issue.

Postpartum screening for diabetes after a gestational diabetes mellitus-affected pregnancy.

OBJECTIVE: To estimate trends in postpartum glucose testing in a cohort of women with gestational diabetes mellitus (GDM). METHODS: A validated computerized algorithm using Kaiser Permanente Northwest automated data systems identified 36,251 live births or stillbirths from 1999 through 2006. The annual percentage of pregnancies complicated by gestational diabetes with clinician orders for and completion of a fasting plasma glucose (FPG) test within 3 months of delivery was calculated. Logistic regression with generalized estimating equations was used to test for statistically significant trends. RESULTS: The percentages of pregnancies affected by GDM increased from 2.9% in 1999 to 3.6% in 2006 (P<.01). Clinician orders for postpartum tests increased from 15.9% in 1999 to 79.3% in 2004 (P<.01), and then remained stable through 2006. Completed FPG tests increased from 9.0% in 1999 to 57.8% in 2004 (P<.01), and then remained stable through 2006. No oral glucose tolerance tests were ordered. From 2004 to 2006, the practice site where women received care was the factor most strongly associated with the clinician order, but it was not predictive of test completion. Among women with clinician orders, those who were Asian or Hispanic or who attended the 6-week postpartum examination were more likely to complete the test than their counterparts. CONCLUSION: Postpartum glucose testing in women with GDM-affected pregnancies increased over time. However, even in recent years, 42% of women with GDM-affected pregnancies failed to have a postpartum FPG test, and no test was ordered for 21% of GDM-affected pregnancies. LEVEL OF EVIDENCE: II