Breastfeeding and later maternal risk of hypertension and cardiovascular disease - The role of overall and abdominal obesity.

In this study, we examined how any, full, and partial breastfeeding durations were associated with maternal risk of hypertension and cardiovascular disease (CVD), and how prepregnancy body mass index (BMI) and waist circumference 7 years postpartum influenced these associations. A total of 63,260 women with live-born singleton infants in the Danish National Birth Cohort (1996-2002) were included. Interviews during pregnancy and 6 and 18 months postpartum provided information on prepregnancy weight, height, and the duration of full and partial breastfeeding. Waist circumference was self-reported 7 years postpartum. Cox regression models were used to estimate hazard ratios of incident hypertension and CVD, registered in the National Patient Register from either 18 months or 7 years postpartum through 15 years postpartum. Any breastfeeding ≥4 months was associated with 20-30% lower risks of hypertension and CVD compared to <4 months in both normal/underweight and overweight/obese women. At follow-up starting 7 years postpartum, similar risk reductions were observed after accounting for waist circumference adjusted for BMI. Partial breastfeeding >2 months compared to ≤2 months, following up to 6 months of full breastfeeding, was associated with 10-25% lower risk of hypertension and CVD. Compared with short breastfeeding duration, additional partial breastfeeding was as important as additional full breastfeeding in reducing risk of hypertension and CVD. Altogether, longer duration of breastfeeding was associated with lower maternal risk of hypertension and CVD irrespective of prepregnancy BMI and abdominal adiposity 7 years after delivery. Both full and partial breastfeeding contributed to an improved cardiovascular health in mothers.

Rare and Common Variants Conferring Risk of Tooth Agenesis.

We present association results from a large genome-wide association study of tooth agenesis (TA) as well as selective TA, including 1,944 subjects with congenitally missing teeth, excluding third molars, and 338,554 controls, all of European ancestry. We also tested the association of previously identified risk variants, for timing of tooth eruption and orofacial clefts, with TA. We report associations between TA and 9 novel risk variants. Five of these variants associate with selective TA, including a variant conferring risk of orofacial clefts. These results contribute to a deeper understanding of the genetic architecture of tooth development and disease. The few variants previously associated with TA were uncovered through candidate gene studies guided by mouse knockouts. Knowing the etiology and clinical features of TA is important for planning oral rehabilitation that often involves an interdisciplinary approach.

Depressive symptoms in women's midlife in relation to their body weight before, during and after childbearing years.

OBJECTIVE: This study aimed to examine how weight and weight changes related to pregnancy were associated with depressive symptoms 11-16 years after childbirth. METHOD: We followed 16,998 first-time mothers from the Danish National Birth Cohort up till 16 years after birth and estimated associations between depressive symptoms and pre-pregnancy body mass index (BMI) (kg m-2), weight changes in different time periods, and BMI-adjusted waist circumference 7 years after birth (WCBMI, cm). Depressive symptoms were estimated by the Center for Epidemiologic Studies Depression 10-item scale. Multiple logistic regression analyses were used to estimate odds ratios (OR) and 95% confidence intervals. RESULTS: Compared with normal-weight, we found that underweight, overweight and obesity were associated with greater odds of depressive symptoms (1.29, 1.24 and 1.73, respectively). Compared with weight change ±1 BMI unit during the total follow-up period, greater odds for depressive symptoms were observed with weight loss (OR 1.14, 0.96-1.36) or gain of 2-2.99 kg m-2 (OR 1.11, 0.92-1.33) or gain of ≥3 kg m-2 (OR 1.68, 1.46-1.94). WCBMI > 2.2 cm was associated with greater odds of depressive symptoms (OR 1.16, 0.99-1.36) than waist circumference as predicted by BMI. CONCLUSION: Low and high pre-pregnancy BMI, weight changes and WCBMI larger than predicted were associated with more depressive symptoms in midlife.

The experience of demanding work environments in younger workers.

BACKGROUND: Investigating whether certain individual or background characteristics are associated with an increased risk of experiencing an excessively demanding work environment in younger workers may help to reduce future inequality in health and maximize their labour market participation. AIMS: To describe the work environment of Danish 20- to 21-year olds and to investigate the influence of family socioeconomic background and individual characteristics at age 14-15 on later experience of physical and psychosocial work environments. METHODS: We obtained information on subjects' school performance, vulnerability, health and parental socioeconomic status from registers and a questionnaire completed in 2004. A questionnaire concerning eight measures of subjects' psychosocial and physical work environment in 2010 was used to determine the outcomes of interest. RESULTS: The study population consisted of 679 younger workers aged 20-21. The psychosocial work environment was in general good but younger workers experienced more demanding physical work than the general working population. Overall, individual as well as family factors had a limited impact on their assessment of the work environment. Low self-esteem at age 14-15 was associated with experiencing high demands and lack of trust and fairness at work, whereas low parental socioeconomic status was associated with a demanding physical work environment. CONCLUSIONS: This study showed a social gradient in experiencing a demanding physical work environment at age 20-21. The psychosocial work environment experienced by younger workers was generally good, but vulnerable young people may need special attention to protect them from or prepare them for psychosocially demanding jobs later in life.

Maternal pre-pregnancy body mass index and pubertal development among sons.

Maternal overweight and obesity in pregnancy has been associated with earlier age of menarche in daughters as well as reduced semen quality in sons. We aimed at investigating pubertal development in sons born by mothers with a high body mass index (BMI). The study included 2522 sons of mothers that during pregnancy in 1984-1987 were enrolled in a mother-child cohort and gave information on their pre-pregnancy height and weight from which we calculated their BMI. Information on sons' pubertal development, assessed by age when starting regular shaving, voice break, acne and first nocturnal emission, was obtained from web-based questionnaires in 2005, when sons were 18-21 years old. Multiple linear regression analyses showed that sons of obese mothers on average started to shave regularly 8.3 (95% confidence interval: 2.5-14.0) months earlier than sons of normal weight mothers. For the three other indicators of pubertal development, results also indicated earlier pubertal development among sons of obese mothers. After excluding sons of underweight mothers in a subanalysis, we observed an inverse trend between maternal pre-pregnancy BMI and age at regular shaving, acne and first nocturnal emission. In conclusion, maternal pre-pregnant obesity may be related to earlier timing of pubertal milestones among sons. More research, preferably based on prospectively collected information about pubertal development, is needed to draw firm conclusions.

Maternal bereavement in the antenatal period and oral cleft in the offspring.

STUDY QUESTION: Is maternal bereavement (emotional stress) due to loss of a close relative in the antenatal period associated with the risk of oral cleft in the offspring? SUMMARY ANSWER: Our study suggests prenatal maternal bereavement is associated with an increased risk of oral cleft in the offspring, especially when the bereavement was due to a sudden death or death of a child. WHAT IS KNOWN ALREADY: The aetiology of oral cleft is unknown but includes both genetic and environmental causes. STUDY DESIGN, SIZE AND DURATION: We performed a population-based cohort study based on several national registers in Denmark from 1978 to 2008. PARTICIPANTS/MATERIALS, SETTING, METHODS: Our final study population consisted of 1 771 663 children. Of these 35 118 (2%) were born to mothers who experienced bereavement in the exposure window from 1 year before pregnancy to the end of the first trimester. MAIN RESULTS AND THE ROLE OF CHANCE: In total, 3043 children were diagnosed with a cleft; 968 with cleft lip, 1206 with cleft lip and palate and 869 with a cleft palate. For overall bereavement the prevalence was 1.7 per 1 000 live born in the unexposed children and 2.2 per 1 000 live born in the exposed children. Overall, maternal bereavement due to the death of a close relative from 1 year before conception to the end of the first trimester was associated with a significantly increased risk of oral cleft [odds ratio (OR): 1.28, 95% confidence interval (CI): 1.01; 1.61). When mothers lost a relative due to a sudden death, the risk of oral cleft in the offspring was higher (OR: 1.76, 95% CI: 1.06; 2.94). Losing a relative in the time period before pregnancy and during the first trimester showed a tendency to an increased risk. The risk increase was 77% when the mother was bereaved due to sudden death and the estimation was robust in different analytical strategies. LIMITATIONS, REASONS FOR CAUTION: It is a limitation that we only studied live born children, but most children with isolated oral cleft would survive their pregnancy and birth. Since oral cleft are rare and despite the large study population, we still had a relatively small number of cases, which results in limited power to detect small differences. We did not have actual measurements of the maternal cortisol concentration, but we believe that bereavement due to death of a close relative produces a strong stress reaction in most people. Also we did not have the opportunity to adjust for intake of folic acid and use of anti-depressant; however, analysis in a subset of the data showed no difference in these intakes between exposed and unexposed mothers. WIDER IMPLICATIONS OF THE FINDINGS: With this study we add a large-scale human cohort study to the body of literature on stress and birth defects. Our study is in agreement with previously published results and can be generalized to similar populations like the native Danish population. Severe stress may be added to the list of potential causes for oral cleft.

Self-hypnosis for coping with labour pain: a randomised controlled trial.

OBJECTIVE: To estimate the use of epidural analgesia and experienced pain during childbirth after a short antenatal training course in self-hypnosis to ease childbirth. DESIGN: Randomised, controlled, single-blinded trial using a three-arm design. SETTING: Aarhus University Hospital Skejby in Denmark during the period July 2009 until August 2011. POPULATION: A total of 1222 healthy nulliparous women. METHOD: Use of epidural analgesia and self-reported pain during delivery was compared in three groups: a hypnosis group receiving three 1-hour lessons in self-hypnosis with additional audiorecordings to ease childbirth, a relaxation group receiving three 1-hour lessons in various relaxation methods and mindfulness with audiorecordings for additional training, and a usual care group receiving ordinary antenatal care only. PRIMARY OUTCOME: Use of epidural analgesia. Secondary outcomes included self-reported pain. RESULTS: There were no between-group differences in use of epidural analgesia-31.2% (95% confidence interval [95% CI] 27.1-35.3) in the hypnosis group, 29.8% (95% CI 25.7-33.8) in the relaxation group and 30.0% (95% CI 24.0-36.0) in the control group. No statistically significant differences between the three groups were observed for any of the self-reported pain measures. CONCLUSION: In this large randomised controlled trial of a brief course in self-hypnosis to ease childbirth, no differences in use of epidural analgesia or pain experience were found across study groups. Before turning down self-hypnosis as a method for pain relief, further studies are warranted with focus on specific subgroups.

Waiting time to pregnancy according to maternal birthweight and prepregnancy BMI.

BACKGROUND: An association between a woman's own birthweight and her fecundity has been suggested, but no empirical data have been published on the association between maternal birthweight and waiting time to pregnancy (TTP). METHODS: In the Danish National Birth Cohort (1996-2002), which is an ongoing study of 92 274 women and their pregnancies, information about TTP and prepregnancy BMI was collected during pregnancy. At the 7-year follow-up of the children, 21 786 mothers reported their own birthweight and whether they were born at term or preterm. The association between maternal birthweight and TTP is presented as adjusted odds ratios with 95% confidence intervals. RESULTS: Low maternal birthweight (< or =2500 g for term and < or =1500 g for preterm birth) was associated with an increased risk of TTP of >1 year [term: 1.2 (1.0-1.5); preterm: 1.8 (1.1-3.1)]. The latter association was strongest in women with a BMI < 25 kg/m(2) [2.6 (1.4-4.7)]. High maternal birthweight (>4500 g for term and >3500 g for preterm) was also associated with an increased risk of TTP of >1 year [1.5 (1.0-2.0) and 1.3 (0.7-2.4), respectively], especially in women with a BMI > or = 25 kg/m(2) [1.8 (1.1-3.1) and 2.5 (1.0-6.4), respectively]. CONCLUSIONS: High or low maternal birthweight was associated with TTP > 1 year. Longer waiting times in women with very low birthweight may reflect an effect of being born very preterm. Subfecundity may partly be programmed in foetal life by factors that cause or correlate with foetal growth.

Is maternal obesity related to semen quality in the male offspring? A pilot study.

BACKGROUND: Obesity is a strong predictor of fecundity and maternal obesity may well program semen quality during pregnancy, but to our knowledge, no published studies have evaluated this hypothesis. METHODS: From a Danish pregnancy cohort established in 1984-87, 347 out of 5109 sons were selected for a follow-up study conducted from February 2005 to January 2006. Semen and blood samples were analyzed for conventional semen characteristics and reproductive hormones and related to information on maternal pre-pregnant body mass index (BMI) that was available for 328 men. Of these, 34 were sons of underweight, and 25 sons of overweight, mothers. RESULTS: Inhibin B decreased with increasing maternal BMI (P = 0.04) and the point estimates for sperm concentration, semen volume, percent motile sperm, testosterone and FSH suggested an impaired reproductive status among sons of overweight mothers, but none of the trends were statistically significant. CONCLUSIONS: The results suggest that there may be an effect of high maternal BMI on the sons' semen quality, but the study had only enough power to justify a critical evaluation of the hypothesis in a larger study.

Subfecundity in overweight and obese couples.

BACKGROUND: Recent studies indicate that not only women's but also men's obesity has adverse effects on fecundity and since fecundity is a couple concept, we examined fecundity in relation to overweight and obesity of the couple. We also examined the association between weight changes and fecundity over time. METHODS: Between 1996 and 2002, 64 167 pregnant women enrolled in the Danish National Birth Cohort were interviewed during and 18 months after pregnancy. Information on body mass index (BMI) and waiting time to pregnancy (TTP) was available for 47 835 couples. RESULTS: Among men and women with a BMI of 18.5 kg/m(2) or more, we found a dose-response relationship between increasing BMI group and subfecundity (a TTP of more than 12 months): Odds ratio (OR) = 1.32 (95% CI: 1.26-1.37) for women and OR = 1.19 (95% CI: 1.14-1.24) for men. Among 2374 women with an initial BMI of 18.5 kg/m(2) or more, who participated more than once in the Danish National Birth Cohort, each kilogram increment in weight between the two pregnancies was associated with a 2.84 (95% CI: 1.33-4.35) days longer TTP. CONCLUSIONS: Couples have a high risk of being subfecund if they are both obese.