Tag Archives: birth

Caffeine linked to low birth weight babies

A new study published in the journal BMC Medicine last month shows that caffeine is linked to low birth weight babies (1).

Caffeine intake is already a concern in pregnancy, with current guidelines recommending that pregnant women restrict themselves to no more than 200mg of caffeine (equivalent to around two cups of coffee) each day.

While the placental barrier does a good job of screening out many infectious agents, it is not able to block environmental pollutants such as pesticides, mercury and PCBs. Likewise, caffeine can cross the placental barrier, resulting in babies that are small for gestational age (SGA).

The study monitored the caffeine intake of more than 60,000 pregnant women. For every 100mg of caffeine each day, the average infant lost an estimated 21-28g. Caffeine intake also increased the length of pregnancy, with caffeine from coffee in particular having the most dramatic effect. This suggests that another substance in coffee may also contribute to the negative effects. For example, decaffeinated coffee retains other stimulants such as theophylline and theobromine.

While coffee is the primary source of caffeine in many diets, there are many other foods and drinks that contribute to overall caffeine intake. This study monitored all sources of caffeine, including coffee, tea, hot chocolate, fizzy drinks, as well as foods such as chocolate and chocolate desserts.

Coffee
Caffeine can cross the placental barrier, resulting in babies that are small for gestational age

As a general guide, a can of coke contains around 30mg caffeine, a cup of tea contains around 50mg caffeine, and a cup of instant coffee contains around 60mg caffeine. ‘Proper’ coffee will provide an even bigger caffeine hit. A medium cup of coffee from a high street coffee chain can contain around 200mg caffeine. For those who regularly visit high street coffee chains it’s important to note that the amount of caffeine in drinks from these stores can vary wildly making it very difficult to determine how much caffeine you are actually drinking.

Staying hydrated is especially important during pregnancy. Drinking plenty of fluids helps lessen the risks of problems such as constipation, urinary infections, fluid retention and haemorrhoids during pregnancy. The volume of blood in your body, which is made mostly of water, also increases during pregnancy.

So what are the best choices of beverage during pregnancy? Water is the most obvious choice for staying hydrated. Keep a bottle at your desk or carry a small bottle in your bag if you’re out and about. If plain water is too boring, try carbonated water and add a slice or two of lemon or lime.

Naturally caffeine-free teas are another good choice. Redbush tea is naturally caffeine free. Peppermint tea can help ease digestive troubles and ginger tea may help to relieve morning sickness. Fruit smoothies using probiotic yoghurt and digestive-boosters such as milled flax seeds is another great option.

Barley water makes a great anti-inflammatory agent for the urinary system which can be more prone to infection during pregnancy. Buy whole barley, put 40g in a litre of water, boil and simmer for 20 minutes. Add a slice of lemon or the juice of one lemon and simmer for a further 10 minutes. Allow to cool, then sip the water throughout the day.

Finally, green smoothies provide all the antioxidants of fruit juice without the sugar hit, and they can be a great source of minerals such as folate and iron which are needed in greater amounts during pregnancy. Try blending a handful of spinach with an avocado, a dash of apple juice, a cup of water, and three tablespoons of plain yoghurt for a refreshing folate and iron-rich green smoothie.

References

1. Sengpiel V et al. (2013) Maternal caffeine intake during pregnancy is associated with birth weight but not with gestational length: results from a large prospective observational cohort study. BMC Medicine 11:42.

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Maternal Vitamin D levels linked to baby’s brain development

Earlier this year I wrote about a study that links vitamin D in pregnancy with children’s body fat levels. Evidence on the importance of vitamin D in pregnancy continues to grow. More recently, a new population-based study has linked expectant mothers’ vitamin D levels with their children’s brain development (1).

The study, to be published this month in Pediatrics, suggests that pregnant women who are deficient in vitamin D are more likely to give birth to children with slower brain development and decreased motor skills.

The Spanish study, a population-based cohort study recruiting 1,820 pregnant women, was conducted between 2003 and 2008. The women had their vitamin D levels measured during their second trimester of pregnancy. Later, their children’s mental development was assessed by trained psychologists.

Vitamin D
Vitamin D supplements can help raise vitamin D levels in the body to an adequate level during pregnancy

The data showed that 20% of the women were deficient in vitamin D, and a further 32% had ‘insufficient levels’ of the vitamin. The babies of mothers who were deficient in vitamin D scored lower on mental and psychomotor tests at the age of 14 months when compared to children of women with adequate vitamin D levels.

To ensure that the study was fair, the authors used statistical techniques to account for other variables that could have influenced the children’s development. These included factors such as birth weight, maternal age, social class and mother’s education level, and whether or not the mother drank alcohol or smoked during pregnancy.

The differences in scores were significant, with the children of vitamin D deficient mothers scoring 2.6 points lower on mental tests and 2.3 points lower on psychomotor tests. Study leader Dr Eva Morales notes that a difference of just 4-5 points in these such tests could result in halving the number of children with above-average IQ scores. As a result, Morales believes that these differences in scores ‘might have an important impact at the population level’.

This is not the first study to look at the effect of maternal vitamin D on children’s development. A study published by the same journal in March this year indicated links between maternal vitamin D deficiency and children’s neurodevelopment (2). This study found that low vitamin D levels in the second trimester of pregnancy were linked with language impairment in children at the ages of 5 and 10 years old.

While these studies show a link between vitamin D deficiency during pregnancy and children’s brain development, they do not prove the existence of a cause-and-effect relationship. Possible reasons for a link include the known role that vitamin D plays in brain function. For example, vitamin D receptors are present throughout the brain, and the vitamin is essential for the formation of neurotrophins, proteins in the brain that help nerve cells to survive and develop.

According to the UK’s National Diet and Nutrition Survey, up to a quarter of people in the UK have low levels of vitamin D in their blood. In its recent statement on vitamin D requirements, the UK Department of Health considers pregnant and breastfeeding women to be an ‘at risk group’. The current recommendation for vitamin D in pregnancy is 10 mcg, or 400 IU, and the UK Department of Health advises that all pregnant women should supplement this amount. As new evidence comes to light regarding the essential role of this vitamin in children’s development, this advice seems more pertinent than ever.

Written by Nadia Mason, BSc MBANT NTCC CNHC

References

1. Morales et al (2012) Circulating 25-Hydroxyvitamin D3 in Pregnancy and Infant Neuropsychological Development. Pediatrics. Published online ahead of publication in Sept 2012.

2.Whitehouse A et al (2012) Maternal Serum Vitamin D Levels During Pregnancy and Offspring Neurocognitive Development. Pediatrics Vol. 129 No. 3 pp. 485 -493.

 

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