Pregnancy weight gain by gestational age and stillbirth: a population-based cohort study.

OBJECTIVE: To study the association between total and early pregnancy (<22 completed weeks) weight gain and risk of stillbirth, stratified by early-pregnancy body mass index (BMI). DESIGN: Population-based cohort study. SETTING: Stockholm-Gotland Region, Sweden. POPULATION: Pregnant women with singleton births (n = 160 560). METHODS: Pregnancy weight gain was standardised into gestational age-specific z-scores. For analyses of total pregnancy weight gain, a matched design with an incidence density sampling approach was used. Findings were also contrasted with current Institute of Medicine (IOM) weight gain recommendations. MAIN OUTCOME MEASURES: Stillbirth defined as fetal death at ≥22 completed weeks of gestation. RESULTS: For all BMI categories, there was no statistical association between total or early pregnancy weight gain and stillbirth within the range of a weight gain z-score of -2.0 SD to +2.0 SD. Among normal-weight women, the adjusted odds ratio of stillbirth for lower (-2.0 to -1.0 SD) and higher (+1.0 to +1.9 SD) total weight gain was 0.85 (95% CI; 0.48-1.49) and 1.03 (0.60-1.77), respectively, as compared with the reference category. Further, there were no associations between total or early pregnancy weight gain and stillbirth within the range of weight gain currently recommended by the IOM. For the majority of the BMI categories, the point estimates at the extremes of weight gain values (<-2.0SD and ≥2.0 SD) suggested protective effects of low weight gain and increased risks of high weight gain, but estimates were imprecise and not statistically significant. CONCLUSION: We found no associations between total or early pregnancy weight gain and stillbirth across the range of weight gain experienced by most women. TWEETABLE ABSTRACT: There was no association between weight gain during pregnancy and stillbirth among most women.

Vitamin D, pre-eclampsia, and preterm birth among pregnancies at high risk for pre-eclampsia: an analysis of data from a low-dose aspirin trial.

OBJECTIVE: To examine the relation between maternal vitamin D status and risk of pre-eclampsia and preterm birth in women at high risk for pre-eclampsia. DESIGN: Analysis of prospectively collected data and blood samples from a trial of prenatal low-dose aspirin. SETTING: Thirteen sites across the USA. POPULATION: Women at high risk for pre-eclampsia. METHODS: We measured 25-hydroxyvitamin D [25(OH)D] concentrations in stored maternal serum samples drawn at 12-26 weeks' gestation (n = 822). We used mixed effects models to examine the association between 25(OH)D and risk of pre-eclampsia and preterm birth, controlling for confounders including prepregnancy BMI and race. MAIN OUTCOME MEASURES: Pre-eclampsia and preterm birth. RESULTS: Twelve percent of women were vitamin D deficient [25(OH)D <30 nmol/l]. Women with 25(OH)D <30 versus ≥75 nmol/l had a 2.4-fold (95% CI 1.0-5.6) higher risk of early-onset pre-eclampsia (<35 weeks' gestation) after confounder adjustment. Women with 25(OH)D <50 nmol/l had a 1.8-fold (95% CI 1.0-3.2) increased risk of preterm birth at <35 weeks compared with women who had 25(OH)D ≥75 nmol/l, which was driven by indicated preterm births at <35 weeks' gestation [25(OH)D <50 versus ≥75 nmol/l adjusted RR 2.5 (95% CI 1.1-5.8)]. There was no association between vitamin D status and pre-eclampsia or preterm birth at <37 weeks. CONCLUSION: Maternal vitamin D status in the second trimester was inversely associated with risk of early-onset pre-eclampsia and preterm birth at <35 weeks in women at high risk for pre-eclampsia. TWEETABLE ABSTRACT: Vitamin D is inversely related to risk of pre-eclampsia and preterm birth at <35 weeks in high-risk pregnancies.

Gestational weight gain, prepregnancy body mass index and offspring attention-deficit hyperactivity disorder symptoms and behaviour at age 10.

OBJECTIVE: To assess offspring attention-deficit hyperactivity disorder (ADHD) symptoms and emotional/behavioural impairments at age 10 years in relation to maternal gestational weight gain (GWG) and prepregnancy body mass index (BMI). DESIGN AND SETTING: Longitudinal birth cohort from Magee-Womens Hospital, Pittsburgh, Pennsylvania (enrolled 1983-86). POPULATION: Mother-infant dyads (n = 511) were followed through pregnancy to 10 years. METHODS: Self-reported total GWG was converted to gestational-age-standardised z-scores. Multivariable linear and negative binomial regressions were used to estimate effects of GWG and BMI on outcomes. MAIN OUTCOME MEASURES: Child ADHD symptoms were assessed with the Conners' Continuous Performance Test. Child behaviour was assessed by parent and teacher ratings on the Child Behaviour Checklist (CBCL) and Teacher Report Form, respectively. RESULTS: The mean (SD) total GWG (kg) was 14.5 (5.9), and 10% of women had a pregravid BMI ≥30 kg/m2 . Prepregnancy obesity (BMI of 30 kg/m2 ) was associated with increased offspring problem behaviours including internalising behaviours (adjusted ß 3.3 points, 95% CI 1.7-4.9), externalising behaviours (adjusted ß 2.9 points, 95% CI 1.4-4.6), and attention problems (adjusted ß 2.3 points, 95% CI 1.1-3.4) on the CBCL, compared with normal weight mothers (BMI of 22 kg/m2 ). There were nonsignificant trends towards increased offspring impulsivity with low GWG among lean mothers (adjusted incidence rate ratio 1.2, 95% CI 0.9-1.5) and high GWG among overweight mothers (adjusted incidence rate ratio 1.7, 95% CI 0.9-2.8), but additional outcomes did not differ by GWG z-score. Results were not meaningfully different after excluding high-substance users. CONCLUSIONS: In a low-income and high-risk sample, we observed a small increase in child behaviour problems among children of obese mothers, which could have an impact on child behaviour in the population. TWEETABLE ABSTRACT: Maternal obesity is associated with a small increase in child behaviour problems.

Gestational weight gain and the risk of offspring obesity at 10 and 16 years: a prospective cohort study in low-income women.

OBJECTIVE: To study the association between gestational weight gain (GWG) and offspring obesity risk at ages chosen to approximate prepuberty (10 years) and postpuberty (16 years). DESIGN: Prospective pregnancy cohort. SETTING: Pittsburgh, PA, USA. SAMPLE: Low-income pregnant women (n = 514) receiving prenatal care at an obstetric residency clinic and their singleton offspring. METHODS: Gestational weight gain was classified based on maternal GWG-for-gestational-age Z-score charts and was modelled using flexible spline terms in modified multivariable Poisson regression models. MAIN OUTCOME MEASURES: Obesity at 10 or 16 years, defined as body mass index (BMI) Z-scores ≥95th centile of the 2000 CDC references, based on measured height and weight. RESULTS: The prevalence of offspring obesity was 20% at 10 years and 22% at 16 years. In the overall sample, the risk of offspring obesity at 10 and 16 years increased when GWG exceeded a GWG Z-score of 0 SD (equivalent to 30 kg at 40 weeks); but for gains below a Z-score of 0 SD there was no relationship with child obesity risk. The association between GWG and offspring obesity varied by prepregnancy BMI. Among mothers with a pregravid BMI <25 kg/m(2) , the risk of offspring obesity increased when GWG Z-score exceeded 0 SD, yet among overweight women (BMI ≥25 kg/m(2) ), there was no association between GWG Z-scores and offspring obesity risk. CONCLUSIONS: Among lean women, higher GWG may have lasting effects on offspring obesity risk.

Maternal vitamin D status, prolonged labor, cesarean delivery and instrumental delivery in an era with a low cesarean rate.

OBJECTIVE: To examine the association between maternal 25-hydroxyvitamin D (25(OH)D) and adverse labor and delivery outcomes. STUDY DESIGN: We measured serum 25(OH)D at ⩽ 26 weeks gestation in a random subsample of vertex, singleton pregnancies in women who labored (n=2798) from the 12-site Collaborative Perinatal Project (1959 to 1966). We used labor and delivery data to classify cases of adverse outcomes. RESULT: Twenty-four percent of women were vitamin D deficient (25(OH)D <30 nmol l(-1)), and 4.5, 3.3, 1.9 and 7.5% of women had prolonged stage 1 labor, prolonged stage 2 labor, primary cesarean delivery or indicated instrumental delivery, respectively. After adjustment for prepregnancy body mass index, race and study site, 25(OH)D concentrations were not associated with risk of prolonged stage 1 or 2, cesarean delivery or instrumental delivery. CONCLUSION: Maternal vitamin D status at ⩽ 26 weeks was not associated with risk of prolonged labor or operative delivery in an era with a low cesarean rate.

Is gestational weight gain associated with offspring obesity at 36 months?

OBJECTIVE: We examined the association between gestational weight gain (GWG) and offspring obesity at age 36 months. METHODS: Mother-infant dyads (n = 609) were followed from a first study visit (mean [standard deviation]: 18.8 [2.7] weeks gestation) to 36 months postpartum. Total GWG over the entire pregnancy was defined as excessive or non-excessive according to the 2009 Institute of Medicine guidelines. Four mutually exclusive categories of excessive or non-excessive GWG across early (conception to first study visit) and late (first study visit to delivery) pregnancy defined GWG pattern. Body mass index (BMI) z-scores ≥95th percentile of the 2000 Centers for Disease Control (CDC) references defined offspring obesity at 36 months. Multivariable log-binomial models adjusted for pre-pregnancy BMI and breastfeeding were used to estimate the association between GWG and childhood obesity risk. RESULTS: Nearly half of the women had total excessive GWG. Of these, 46% gained excessively during both early and late pregnancy while 22% gained excessively early and non-excessively late, and the remaining 32% gained non-excess weight early and excessively later. Thirteen per cent of all children were obese at 36 months. Excessive total GWG was associated with more than twice the risk of child obesity (adjusted risk ratio [95% confidence interval]: 2.20 [1.35, 3.61]) compared with overall non-excessive GWG. Compared with a pattern of non-excessive GWG in both early and late pregnancy, excessive GWG in both periods was associated with an increased risk of obesity (2.39 [1.13, 5.08]). CONCLUSIONS: Excessive GWG is a potentially modifiable factor that may influence obesity development in early childhood.

Gestational weight gain in twin pregnancies and maternal and child health: a systematic review.

Our objective was to systematically review the data interrogating the association between gestational weight gain (GWG) and maternal and child health among women with twin gestations. We identified 15 articles of twin gestations that studied GWG in relation to a maternal, perinatal or child health outcome and controlled for gestational age at delivery and prepregnancy body mass index. A positive association between GWG and fetal size was consistently found. Evidence on preterm birth and pregnancy complications was inconsistent. The existing studies suffer from serious methodological weaknesses, including not properly accounting for the strong correlation between gestational duration and GWG and not controlling for chorionicity. In addition, serious perinatal outcomes were not studied, and no research is available on the association between GWG and outcomes beyond birth. Our systematic review underscores that GWG in twin gestations is a neglected area of research. Rigorous studies are needed to inform future evidence-based guidelines.

Early-pregnancy maternal vitamin D status and maternal hyperglycaemia.

AIMS: To estimate the association between serum 25-hydroxyvitamin D concentrations and maternal hyperglycaemia (post-load glucose concentration ≥ 7.5 mmol/l). METHODS: Pregnant women (n = 429; 61% black, 36% obese, 45% smokers) enrolled in a cohort study at <16 weeks gestation. Non-fasting blood samples were assayed for serum 25-hydroxyvitamin D at enrolment. At 24-28 weeks gestation, maternal hyperglycaemia was determined using a 50-g 1-h oral glucose challenge test. RESULTS: A total of 67% of women had 25-hydroxyvitamin D concentrations < 50 nmol/l and 11% had maternal hyperglycaemia. Among smokers, each 23-nmol/l increase in serum 25-hydroxyvitamin D was associated with a reduction in the odds of maternal hyperglycaemia [odds ratio: 0.30 (95% CI: 0.13, 0.68)] after adjustment for parity, race/ethnicity, age, pre-pregnancy BMI, marital status, income, family history of diabetes, and gestational age of gestational diabetes mellitus screening. Among non-smokers, we found no association between early pregnancy vitamin D status and maternal hyperglycaemia. CONCLUSIONS: Smoking status may modify the relationship between poor maternal vitamin D status and maternal hyperglycaemia.

Activation of the fibrinolytic cascade early in pregnancy among women with spontaneous preterm birth.

OBJECTIVE: To evaluate the association of early pregnancy concentrations of thrombin-antithrombin III complex with subsequent spontaneous preterm birth. METHODS: In a nested case-control study, thrombin-antithrombin III complex was measured in plasma before 20 weeks of gestation (mean 9.9 weeks) among women without chronic conditions, preeclampsia, or growth restriction. C-reactive protein and non-high-density lipoprotein cholesterol were also measured. Women with spontaneous preterm birth before 34 weeks of gestation (n=29) and 34 weeks to 36 weeks of gestation (n=72) were compared with women with term births occurring at or after 37 weeks (n=219). Polychotomous logistic regression was used to relate elevated thrombin-antithrombin III complex (greater than 5.5 ng/mL), dyslipidemia (non-high-density lipoprotein cholesterol greater than the 90th percentile), and inflammation (C-reactive protein at or above 8 micrograms/mL) to risk of spontaneous preterm birth subtypes. RESULTS: Women with spontaneous preterm birth compared with term births had elevated thrombin-antithrombin III complex (P=.02), and they were more likely to have a thrombin-antithrombin III complex greater than 5.5 ng/mL (P<.01). Women with thrombin-antithrombin III complex in the highest compared with lowest quartile had a 4.6-fold (95% confidence interval 1.3-15.8) increased risk for spontaneous preterm birth before 34 weeks of gestation, adjusted for body mass index, race, inflammation, dyslipidemia, and gestational age at sampling. There was a dose-response trend between thrombin-antithrombin III complex and spontaneous preterm birth before 34 weeks (P<.01) and 34 to 36 weeks (P=.03). CONCLUSION: There is evidence of early pregnancy systemic fibrinolysis among women with spontaneous preterm birth before 34 weeks of gestation independent of inflammation and dyslipidemia, perhaps secondary to microvascular injury. LEVEL OF EVIDENCE: II.

High prevalence of postpartum anemia among low-income women in the United States.

OBJECTIVE: To determine the prevalence of anemia from 4 to 26 weeks post partum and to examine prenatal predictors of postpartum anemia. STUDY DESIGN: Retrospective cohort analysis of 59,428 participants in the Special Supplemental Nutrition Program for Women, Infants, and Children in 12 US states. RESULTS: The prevalence of postpartum anemia was 27%. Anemia rates were higher among minority women, reaching 48% among non-Hispanic black women. Of 9129 women who had normal hemoglobin in the third trimester, 21% had postpartum anemia. Prenatal anemia was the strongest predictor of postpartum anemia (adjusted odds ratio, 2.7; 95% confidence interval, 2.5-2.8). Maternal obesity, multiple birth, and not breast-feeding also predicted postpartum anemia. CONCLUSION: The high prevalence of post partum anemia among low-income women highlights the importance of anemia screening at 4 to 6 weeks post partum. These data suggest that screening should not be limited, as it is at present, to women considered at high risk.

Weight training-related injuries in the high school athlete.

Eighty young athletes with weight training-related injuries were seen from August 1976 to August 1980. In 37 of the 80 athletes, it was difficult to pinpoint the cause of injury since the history revealed, in addition to weight training, either a program of running excessive mileage or participation in repetitive lap running in the gymnasium. The injuries of the remaining 43 athletes had a direct causal relationship to the weight training program. Twenty-nine developed lumbosacral pain. Seven of the 29 were hospitalized, and four required surgical treatment. Anterior iliac spine avulsion occurred in six cases, and laceration of the knee meniscus occurred as an initial injury in four athletes who required surgery. Four athletes developed a cervical sprain. Universal Gym (Cedar Rapids, IA), Leaper (Strength/Fitness Systems, Independence MO) Orthotron (Lumex Inc., Bay Shore, NY), and free weights were used either singly or in combination by these young athletes in weight training.