First trimester coffee and tea intake and risk of gestational diabetes mellitus: a study within a national birth cohort.

OBJECTIVE: Coffee and tea consumption is associated with a decreased type 2 diabetes risk in non-pregnant adults. We examined the relation between first trimester coffee and tea consumption and gestational diabetes mellitus (GDM) risk. DESIGN: Population-based cohort study. SETTING: Denmark 1996-2002. POPULATION: Non-diabetic women with singleton pregnancies in the Danish National Birth Cohort (n = 71,239). METHODS: Estimated adjusted relative risks (RR) and 95% confidence intervals (95%CI) for the association between first trimester coffee and tea or estimated total caffeine and GDM. MAIN OUTCOME MEASURES: GDM ascertained from the National Hospital Discharge Register or maternal interview. RESULTS: Coffee or tea intake was reported in 81.2% (n = 57,882) and 1.3% (n = 912) of pregnancies were complicated by GDM. Among non-consumers, 1.5% of pregnancies were complicated by GDM. Among coffee drinkers, GDM was highest among women who drank ≥8 cups/day (1.8%) with no significant difference across intake levels (P = 0.10). Among tea drinkers, there was no difference in GDM across intake levels (1.2%; P = 0.98). After adjustment for age, socio-occupational status, parity, pre-pregnancy body mass index, smoking, and cola, there was suggestion of a protective, but non-significant association with increasing coffee (RR ≥8 versus 0 cups/day = 0.89 [95%CI 0.64-1.25]) and tea (RR ≥8 versus 0 cups/day = 0.77 [95%CI 0.55-1.08]). Results were similar by smoking status, except a non-significant 1.45-fold increased risk with ≥8 coffee cups/day for non-smokers. There was a non-significant reduced GDM risk with increasing total caffeine. CONCLUSIONS: Our results suggest that moderate first trimester coffee and tea intake were not associated with GDM increased risk and possibly may have a protective effect.

Maternal overweight and obesity and risk of congenital heart defects in offspring.

OBJECTIVE: Obesity is a risk factor for congenital heart defects (CHDs), but whether risk is independent of abnormal glucose metabolism remains unknown. Data on whether overweight status increases the risk are also conflicting. RESEARCH DESIGN AND METHODS: We included 121 815 deliveries from a cohort study, the Consortium on Safe Labor (CSL), after excluding women with pregestational diabetes as recorded in the electronic medical record. CHD was identified via medical record discharge summaries. Adjusted odds ratios (ORs) for any CHD were calculated for prepregnancy body mass index (BMI) categories of overweight (25-<30 kg m(-2)), obese (30-<40 kg m(-2)) and morbidly obese (≥40 kg m(-2)) compared with normal weight (18.5-<25 kg m(-2)) women, and for specific CHD with obese groups combined (≥30 kg m(-2)). A subanalysis adjusting for oral glucose tolerance test (OGTT) results where available was performed as a proxy for potential abnormal glucose metabolism present at the time of organogenesis. RESULTS: There were 1388 (1%) infants with CHD. Overweight (OR=1.15, 95% confidence interval (95% CI): 1.01-1.32), obese (OR=1.26, 95% CI: 1.09-1.44) and morbidly obese (OR=1.34, 95% CI: 1.02-1.76) women had greater OR of having a neonate with CHD than normal weight women (P<0.001 for trend). Obese women (BMI≥30 kg m(-2)) had higher OR of having an infant with conotruncal defects (OR = 1.33, 95% CI: (1.03­1.72) [corrected], atrial septal defects (OR=1.22, 95% CI: 1.04-1.43) and ventricular septal defects (OR=1.38, 95% CI: 1.06-1.79). Being obese remained a significant predictor of CHD risk after adjusting for OGTT. CONCLUSION: Increasing maternal weight class was associated with an increased risk for CHD. In obese women, abnormal glucose metabolism did not completely explain the increased risk for CHD; the possibility that other obesity-related factors are teratogenic requires further investigation.

Height and the risk of gestational diabetes: variations by race/ethnicity.

AIMS: Gestational diabetes is a common pregnancy complication affecting races/ethnicities disproportionally. Adult height, an indicator of both genetic and early-life factors, is inconsistently associated with gestational diabetes risk. We examined the association and whether it varies by races in a nationally representative US cohort. METHODS: Analyses were conducted among 135 861 pregnancies in the Consortium on Safe Labor, 5567 of which were diagnosed with gestational diabetes based on medical records review. Generalized estimating equations were used to estimate odds ratios (95% confidence intervals) of gestational diabetes, controlling for other risk factors including body weight. Additionally, a meta-analysis of 15 761 pregnancies with gestational diabetes and 205 828 without gestational diabetes was conducted to estimate the pooled mean difference in height between those with gestational diabetes and control subjects. RESULTS: Height was inversely associated with gestational diabetes risk across races/ethnicities, with the strongest association among Asians (P for interaction < 0.01). Comparing extreme quartiles (> 168 vs. < 157 cm), adjusted odds ratios (95% confidence intervals) were 0.18 (0.09-0.36) for Asians/Pacific Islanders, 0.33 (0.29-0.38) for non-Hispanic white women, 0.39 (0.31-0.51) for Hispanics and 0.59 (0.47-0.75) for non-Hispanic black women. Meta-analysis found women with gestational diabetes to be significantly shorter than others. CONCLUSIONS: Taller women are at lower risk of developing gestational diabetes, with the magnitude of association varying significantly across races/ethnicities.

Differences in risk factors for incident and recurrent small-for-gestational-age birthweight: a hospital-based cohort study.

OBJECTIVE: Examine whether small-for-gestational-age (SGA) risk factors differed by prior SGA birth. DESIGN: Hospital-based cohort study. SETTING: Utah, USA. POPULATION: Electronic medical record data from 25,241 women who were nulliparous at study entry with ≥2 subsequent consecutive singleton deliveries (2002-2010). METHODS: Estimated adjusted relative risks (RR) and 95% confidence intervals (95% CI) for the association between second pregnancy characteristics and SGA risk. Tested for risk factor differences between recurrence and incidence (Pdifference). MAIN OUTCOME MEASURES: Second pregnancy incident (n = 1067) and recurrent SGA (n = 484) determined using a population-based reference. RESULTS: SGA complicated 20.3 and 4.5% of deliveries to women with and without a prior SGA birth, respectively. Young maternal age (Pdifference = 0.01) and pregnancy hypertensive diseases (Pdifference = 0.03) were associated with incident but not recurrent SGA. Significant risk factors for incidence and recurrence were smoking (incident RR = 1.64 [95% CI 1.22-2.19]; recurrent RR = 1.59 [95% CI 1.17-2.17]), short stature (incident RR = 1.34 [95% CI 1.16-1.54]; recurrent RR = 1.54 [95% CI 1.31-1.82]), prepregnancy underweight (incident RR = 1.32 [95% CI 1.07-1.64]; recurrent RR = 1.30 [95% CI 1.03-1.64]), and inadequate weight gain (incident RR = 1.41 [95% CI 1.22-1.64]; recurrent RR = 1.33 [95% CI 1.10-1.60]). Race-ethnicity, marital or insurance status, alcohol, diabetes, asthma, thyroid disease, depression, or interpregnancy interval were not associated with incidence or recurrence. CONCLUSION: There was considerable overlap in the risk factors for SGA recurrence and incidence. Recurrence and incidence risk factors included smoking, short stature, underweight, and inadequate weight gain. Maternal age and hypertensive diseases increased the risk for incidence only. Regardless of the SGA definition, some potentially modifiable risk factors for recurrence were identified.

Gestational diabetes, pre-pregnancy obesity and pregnancy weight gain in relation to excess fetal growth: variations by race/ethnicity.

AIMS/HYPOTHESIS: The escalating rate of childhood obesity is a public health concern worldwide, with children in certain ethnic groups being disproportionately affected. Our objective was to examine the joint effects of pre-pregnancy adiposity, pregnancy weight gain and gestational diabetes (GDM) in relation to excess fetal growth and to identify susceptible races or ethnic populations. METHODS: The risk for delivery of a large-for-gestational-age (LGA) infant, specific to race and fetal sex, was evaluated in 105,985 pregnancies in the Consortium on Safe Labor from 2002-2008. Generalised estimating equations were used to estimate the risk for delivery of LGA infants. Joint effects were employed to evaluate the interplay of three risk factors. Models were stratified by racial group considering one, two or three factors (i.e. pre-pregnancy adiposity, pregnancy weight gain and GDM, with 0 factors as the reference group). RESULTS: Greater pre-pregnancy adiposity, pregnancy weight gain and GDM were independently associated with increased risk of giving birth to an LGA infant across all races (except GDM among non-Hispanic whites), in both underweight and normal-weight women. Among non-Hispanic white, non-Hispanic black and Hispanic women, the three-factor joint effect was associated with substantially increased odds of LGA (OR [95% CI] 11.27 [8.40, 15.11], 7.09 [4.81, 10.45] and 10.19 [6.84, 15.19], respectively). However, for Asian women the joint effect of all three factors (OR [95% CI] 5.14 [2.11, 12.50]) was approximately the same as any of the two factors. CONCLUSIONS/INTERPRETATION: GDM, pre-pregnancy obesity and excessive pregnancy weight gain were jointly associated with elevated risk of giving birth to an LGA infant and the effects varied by race. This suggests that those involved in public health efforts aimed at preventing LGA deliveries should consider variations in racial groups when devising effective strategies.