Lactation and Progression to Type 2 Diabetes Mellitus After Gestational Diabetes Mellitus: A Prospective Cohort Study.

BACKGROUND: Lactation improves glucose metabolism, but its role in preventing type 2 diabetes mellitus (DM) after gestational diabetes mellitus (GDM) remains uncertain. OBJECTIVE: To evaluate lactation and the 2-year incidence of DM after GDM pregnancy. DESIGN: Prospective, observational cohort of women with recent GDM. (ClinicalTrials.gov: NCT01967030). SETTING: Integrated health care system. PARTICIPANTS: 1035 women diagnosed with GDM who delivered singletons at 35 weeks' gestation or later and enrolled in the Study of Women, Infant Feeding and Type 2 Diabetes After GDM Pregnancy from 2008 to 2011. MEASUREMENTS: Three in-person research examinations from 6 to 9 weeks after delivery (baseline) and annual follow-up for 2 years that included 2-hour, 75-g oral glucose tolerance testing; anthropometry; and interviews. Multivariable Weibull regression models evaluated independent associations of lactation measures with incident DM adjusted for potential confounders. RESULTS: Of 1010 women without diabetes at baseline, 959 (95%) were evaluated up to 2 years later; 113 (11.8%) developed incident DM. There were graded inverse associations for lactation intensity at baseline with incident DM and adjusted hazard ratios of 0.64, 0.54, and 0.46 for mostly formula or mixed/inconsistent, mostly lactation, and exclusive lactation versus exclusive formula feeding, respectively (P trend = 0.016). Time-dependent lactation duration showed graded inverse associations with incident DM and adjusted hazard ratios of 0.55, 0.50, and 0.43 for greater than 2 to 5 months, greater than 5 to 10 months, and greater than 10 months, respectively, versus 0 to 2 months (P trend = 0.007). Weight change slightly attenuated hazard ratios. LIMITATION: Randomized design is not feasible or desirable for clinical studies of lactation. CONCLUSION: Higher lactation intensity and longer duration were independently associated with lower 2-year incidences of DM after GDM pregnancy. Lactation may prevent DM after GDM delivery. PRIMARY FUNDING SOURCE: National Institute of Child Health and Human Development.

The study of women, infant feeding and type 2 diabetes after GDM pregnancy and growth of their offspring (SWIFT Offspring study): prospective design, methodology and baseline characteristics.

BACKGROUND: Breastfeeding is associated with reduced risk of becoming overweight or obese later in life. Breastfed babies grow more slowly during infancy than formula-fed babies. Among offspring exposed in utero to maternal glucose intolerance, prospective data on growth during infancy have been unavailable. Thus, scientific evidence is insufficient to conclude that breastfeeding reduces the risk of obesity among the offspring of diabetic mothers (ODM). To address this gap, we devised the Study of Women, Infant Feeding and Type 2 Diabetes after GDM Pregnancy and Growth of their Offspring, also known as the SWIFT Offspring Study. This prospective, longitudinal study recruited mother-infant pairs from the SWIFT Study, a prospective study of women with recent gestational diabetes mellitus (GDM). The goal of the SWIFT Offspring Study is to determine whether breastfeeding intensity and duration, compared with formula feeding, are related to slower growth of GDM offspring during the first year life. This article details the study design, participant eligibility, data collection, and methodologies. We also describe the baseline characteristics of the GDM mother-infant pairs. METHODS: The study enrolled 466 mother-infant pairs among GDM deliveries in northern California from 2009-2011. Participants attended three in-person study exams at 6-9 weeks, 6 months and 12 months after delivery for infant anthropometry (head circumference, body weight, length, abdominal circumference and skinfold thicknesses), as well as maternal anthropometry (body weight, waist circumference and percent body fat). Mothers also completed questionnaires on health and lifestyle behaviors, including infant diet, sleep and temperament. Breastfeeding intensity and duration were assessed via several sources (diaries, telephone interviews, monthly mailings and in-person exams) from birth through the first year of life. Pregnancy course, clinical perinatal and newborn outcomes were obtained from health plan electronic medical records. Infant saliva samples were collected and stored for genetics studies. DISCUSSION: This large, racially and ethnically diverse cohort of GDM offspring will enable evaluation of the relationship of infant feeding to growth during infancy independent of perinatal characteristics, sociodemographics and other risk factors. The longitudinal design provides the first quantitative measures of breastfeeding intensity and duration among GDM offspring during early life.

Study of Women, Infant Feeding, and Type 2 diabetes mellitus after GDM pregnancy (SWIFT), a prospective cohort study: methodology and design.

BACKGROUND: Women with history of gestational diabetes mellitus (GDM) are at higher risk of developing type 2 diabetes within 5 years after delivery. Evidence that lactation duration influences incident type 2 diabetes after GDM pregnancy is based on one retrospective study reporting a null association. The Study of Women, Infant Feeding and Type 2 Diabetes after GDM pregnancy (SWIFT) is a prospective cohort study of postpartum women with recent GDM within the Kaiser Permanente Northern California (KPNC) integrated health care system. The primary goal of SWIFT is to assess whether prolonged, intensive lactation as compared to formula feeding reduces the 2-year incidence of type 2 diabetes mellitus among women with GDM. The study also examines whether lactation intensity and duration have persistent favorable effects on blood glucose, insulin resistance, and adiposity during the 2-year postpartum period. This report describes the design and methods implemented for this study to obtain the clinical, biochemical, anthropometric, and behavioral measurements during the recruitment and follow-up phases. METHODS: SWIFT is a prospective, observational cohort study enrolling and following over 1, 000 postpartum women diagnosed with GDM during pregnancy within KPNC. The study enrolled women at 6-9 weeks postpartum (baseline) who had been diagnosed by standard GDM criteria, aged 20-45 years, delivered a singleton, term (greater than or equal to 35 weeks gestation) live birth, were not using medications affecting glucose tolerance, and not planning another pregnancy or moving out of the area within the next 2 years. Participants who are free of type 2 diabetes and other serious medical conditions at baseline are screened for type 2 diabetes annually within the first 2 years after delivery. Recruitment began in September 2008 and ends in December 2011. Data are being collected through pregnancy and early postpartum telephone interviews, self-administered monthly mailed questionnaires (3-11 months postpartum), a telephone interview at 6 months, and annual in-person examinations at which a 75 g 2-hour OGTT is conducted, anthropometric measurements are obtained, and self- and interviewer-administered questionnaires are completed. DISCUSSION: This is the first, large prospective, community-based study involving a racially and ethnically diverse cohort of women with recent GDM that rigorously assesses lactation intensity and duration and examines their relationship to incident type 2 diabetes while accounting for numerous potential confounders not assessed previously.

Association of Infant Temperament With Subsequent Obesity in Young Children of Mothers With Gestational Diabetes Mellitus.

Importance: Infant temperament is associated with excess weight gain or childhood obesity risk in samples of healthy individuals, although the evidence has been inconsistent. To our knowledge, no prior research has examined this topic among children exposed to gestational diabetes mellitus (GDM) in utero. Objective: To prospectively evaluate infant temperament in association with overweight and obesity status at ages 2 to 5 years among children born to mothers who experienced GDM. Design, Setting, and Participants: This prospective cohort study took place at Kaiser Permanente Northern California medical centers. We studied singleton infants delivered at 35 weeks' gestational age or later to mothers who had been diagnosed with GDM. Data were collected from 2009 to 2016, and data analysis occurred from June 2017 to October 2018. Exposures: The primary exposures in the child's first year were soothability, distress to limitations, and activity aspects of temperament, as assessed by a validated questionnaire. Modifiable covariates in the child's first year included breastfeeding intensity and duration monthly ratio scores, along with the timing of the introduction of sugary beverages and complementary foods. Main Outcomes and Measures: The primary outcome was child overweight and obesity status, assessed at ages 2 to 5 years. Multinomial logistic regression models estimated adjusted odds ratios and 95% CIs for infants whose temperaments were measured at 6 to 9 weeks of age and categorized as elevated (≥75th percentile) or not elevated in the 3 domains. We controlled for nonmodifiable and modifiable covariates across models. Results: A total of 382 mother-infant pairs participted, including 130 infants (34.0%) who were non-Hispanic white, 126 infants (33.0%) who were Hispanic, 96 infants (25.1%) who were Asian, 26 infants (6.8%) who were non-Hispanic black, and 4 infants (1.1%) who were of other races/ethnicities. In descriptive analyses, elevated infant soothability and activity temperaments were associated with the early introduction of 100% fruit juice and/or sugar-sweetened beverages (at ages <6 months) and shorter breastfeeding duration (from 0 to <3 months), while elevated distress to limitations was associated with early introduction of complementary foods (at ages <4 months). Elevated soothability consistently was associated with a higher odds of later childhood obesity, with adjusted odds ratios across models ranging from 2.22 (95% CI, 1.04-4.73) to 2.54 (95% CI, 1.28-5.03). Greater breastfeeding intensity and duration (12-month combined) score was associated with lower odds of obesity, independent of infant temperament and other covariates. Conclusions and Relevance: Among this high-risk population of infants, elevated soothability was associated with early childhood obesity risk, perhaps in part because caregivers use sugary drinks to assuage infants. Soothability temperament may be a novel screening target for early obesity prevention interventions involving responsive feeding and emotion regulation.

Dietary variables associated with substantial postpartum weight retention at 1-year among women with GDM pregnancy.

BACKGROUND: An understanding of the dietary behaviors linked to substantial postpartum weight retention, particularly in women diagnosed with gestational diabetes (GDM), is warranted to focus intervention efforts to prevent future type 2 diabetes. This study evaluates the relationship between dietary food intake at 6-9 weeks postpartum (baseline) and odds of substantial postpartum weight retention (≥ 5 kg) at 1-year in women with GDM. METHODS: The Study of Women, Infant Feeding and Type 2 Diabetes after GDM pregnancy (SWIFT) is a prospective multi-ethnic cohort (75% minority) of 1035 women (aged 20-45 years) with recent GDM who delivered a singleton, live birth (≥35 weeks gestation) and underwent 2-h 75 g OGTTs, anthropometric measurements and other assessments at 6-9 weeks postpartum (baseline) and annually thereafter. Eight hundred and eighty-eight women without diabetes at baseline completed the 18-item PrimeScreen to assess dietary intake and the 13-item Caffeine Survey to assess beverage intake, and completed 1-year follow-up. Average postpartum weight retention was calculated (1-year postpartum weight minus pre-pregnancy weight). Multivariable logistic regression models that estimated baseline dietary intake and odds of substantial postpartum weight retention (SPPWR ≥5 kg above pre-pregnancy weight) versus not SPPWR adjusted for numerous clinical, sociodemographic and behavioral covariates. RESULTS: Compared to eating no fried foods, women who reported eating fried foods ≥5 servings/wk. (n = 32) and 2-4 serv/wk. (n = 208), respectively, had a three-fold and two-fold higher odds of SPPWR (OR = 3.38, 95% CI:1.36-8.38, P = 0.009; OR = 1.99, 95% CI:1.30-3.03, P = 0.02), after adjustment for covariates and other foods and soda intake. Soda intake ≥2 serv/wk. versus none was associated with higher odds of SPPWR (OR = 1.95, 95% CI:1.22-3.11, P = 0.005) adjusted for fried foods and covariates, but was attenuated (OR = 1.61,95% CI:0.98-2.66, p = 0.06) after addition of whole eggs and processed meats. CONCLUSIONS: These findings indicate that interventions should focus on reducing fried foods and soda intake during early postpartum periods to reduce substantial postpartum weight retention in high-risk women with GDM. TRIAL REGISTRATION: NCT01967030; October 2013, Eunice Kennedy Shriver National Institute of Health and Human Development (NICHD).