BACKGROUND: Nutrition in the first 1000 days between pregnancy and 24 months of life is critical for child health, and exclusive breastfeeding is promoted as the infant’s best source of nutrition in the first 6 months. Caffeine is a central nervous system stimulant occurring naturally in some foods and used to treat primary apnoea in premature babies. However high caffeine intake can be harmful, and caffeine is transmitted into breastmilk.

AIM: To systematically review the evidence on the effects of maternal caffeine consumption during breastfeeding on the breastfed child.

METHOD: A systematic search was conducted to October 2017 in MEDLINE, EMBASE, Web of Science, CINAHL, and Cochrane Library. The British Library catalogue, which covers doctoral theses, was searched and PRISMA guidelines followed. Two reviewers screened for experimental, cohort, or case-control studies and performed independent quality assessment using the Newcastle-Ottawa scale. The main reviewer performed data extraction, checked by the second reviewer.

RESULTS: Two cohort, two crossover studies, and one N-of-1 trial were included for narrative synthesis. One crossover and two cohort studies of small sample sizes directly investigated maternal caffeine consumption. No significant effects on 24-hour heart rate, 24-hour sleep time, or frequent night waking of the breastfed child were found. One study found a decreased rate of full breastfeeding at 6 months postpartum. Two studies indirectly investigated caffeine exposure. Maternal chocolate and coffee consumption was associated with increased infant colic, and severe to moderate exacerbation of infant atopic dermatitis. However, whether caffeine was the causal ingredient is questionable. The insufficient and inconsistent evidence available had quality issues impeding conclusions on the effects of maternal caffeine consumption on the breastfed child.

CONCLUSION: Evidence for recommendations on caffeine intake for breastfeeding women is scant, of limited quality and inconclusive. Birth cohort studies investigating the potential positive and negative effects of various levels of maternal caffeine consumption on the breastfed child and breastfeeding mother could improve the knowledge base and allow evidence-based advice for breastfeeding mothers.

Systematic review registration number: CRD42017078790

OBJECTIVE: The aim of this work was to gain knowledge on the health status of pregnant women in Switzerland, especially their attitude to and decisions about diet, use of medication and consumption of drugs, including alcohol and tobacco.

METHODS: Data collected by the consecutive Swiss Health Surveys of 2007 and 2012 on sociodemographic and lifestyle characteristics (including nutrition), type and intake of medication, use of alcohol, tobacco and illicit drugs of the female population were analysed. To compare pregnant with non-pregnant women, a group of 10 times as many non-pregnant women (reference group, n = 3090) was matched with all the participating women who said they were pregnant at the time of the survey (pregnant group, n = 309). The two groups were then compared.

RESULTS: The pregnant and non-pregnant participant groups were comparable with respect to most sociodemographic characteristics and both showed a high awareness of health-related issues. Significantly more pregnant than non-pregnant women revealed a high nutritional awareness, claiming to pay attention to what they ate (78.3 vs 73.0%). Frequent consumption of milk products and fish, and moderate consumption of meat were found more often in the pregnant group. Use of medication was comparable between the two groups, except that pregnant women took pain killers less frequently than did non-pregnant women (30.0 vs 61.5%) and relied more often on prescribed medication. Pregnant women were more restrictive in their alcohol consumption than non-pregnant women. Nevertheless, 10.0 and 1.9% of the pregnant women declared consumption of wine and beer, respectively, in the previous 7 days. Regular smoking was less frequent in the pregnant group than in the reference group (11.7 vs 30.3%) and less intensive (pregnant smokers smoked 3.6 cigarettes fewer per day). A few pregnant women (1.9%) said they consumed marijuana; no other illicit drugs were mentioned.

CONCLUSIONS: In Switzerland, women of child-bearing age revealed high general health-awareness. During pregnancy, a considerable proportion of the women adapted their diet and seemed to refrain from using pain killers and from consuming alcohol, tobacco and illicit drugs. However, since a fairly large minority of the pregnant women mentioned drinking alcohol and/or smoking tobacco, further preventive work is needed.

BACKGROUND: Nutritional factors play an important role in the regulation of blood pressure and in the development of hypertension. In this analysis, we explored the associations of 24-hour urinary Na+, K+ and urea excretion with blood pressure levels and the risk of hypertension in the Swiss population, taking regional linguistic differences into account.

METHODS: The Swiss Survey on Salt is a population based cross-sectional study that included 1336 subjects from the three main linguistic regions (French, German and Italian) of Switzerland. Blood pressure was measured with a validated oscillometric Omron HEM 907 device. Hypertension was defined as current antihypertensive treatment or a mean systolic blood pressure >140 mm Hg and/or diastolic >90 mm Hg, based on eight blood pressure measurements performed at two visits. Na+, K+ and urea excretion were assessed in 24-hour urine collections. We use multiple logistic/linear regressions to explore the associations of urine Na+, K+ and urea with blood pressure / hypertension, taking into account potential confounders and effect modifiers.

RESULTS: The prevalence of hypertension was 30%, 26% and 17% in the German-, French- and Italian- speaking regions respectively, (p-value across regions