The importance of healthy eating whilst pregnant

As part of healthy eating week, we caught up with our Research Postgraduate, AnnieBelle Sassine,  to find out why healthy eating is so important whilst pregnant.

Why is a healthy diet so important during pregnancy?

pregnant blogTwenty years ago, David Barker, Professor of Clinical Epidemiology at the University of Southampton, UK highlighted the crucial role of nutrition during pregnancy, stating, ‘the womb is more important than the home.’ He believed that inadequate diet during pregnancy may impact the baby’s growth and result in a low birth weight/premature baby whose organs haven’t properly aged.  Poor maternal/foetal nutrition can then potentially program risk of heart diseases, diabetes, stroke and cardiovascular diseases in later life (1). Consequently, adequate maternal nutrition during pregnancy is absolutely important as it can help break the vicious intergenerational cycle caused by malnourished girls becoming malnourished mothers at risk of delivering low birth weight infants.

Why is research so important when it comes to nutrition and pregnancy?

A recent study analysing time trends for preterm birth showed a substantial increase in the rate of preterm labor over the past 20 years in 65 countries that had reliable data (2) . It is of no coincidence that the rise in preterm birth has paralleled the start of the global nutrition transition in the early 1980-1990s which was characterized by a shift from the traditional diet high in nutrient-dense fruits, vegetables, fish and whole grains to a Western diet high in energy-dense sugars, fats, and processed foods low in essential fatty acids, micronutrients and trace elements, deficiencies of which have been linked to preterm birth and fetal development (3). In fact, a recent study examined maternal diet at preconception and found a strong association with preterm birth and baby outcomes. Authors have showed that women following a dietary pattern high in fat, sugar and takeaway foods before pregnancy were at an increased risk of delivering preterm and giving birth to infants of shorter length compared to women following a dietary pattern based on protein-rich food sources, fruits and whole grains (4).

Research shows that underweight mothers are at high risk of preterm birth and delivering a low birth weight infant (5), whilst overweight mothers are at an increased risk of diabetes and hypertension during pregnancy (6-9). Therefore, it is important to have a balanced diet, rich in fruits and vegetables, whole grains and fish that ensure adequate amounts of essential micronutrients, which are indispensable for progression of pregnancy and healthy outcomes.

What nutrients are essential during pregnancy?

Thanks to research, the link between folic acid deficiency and neural tube defects has been confirmed and pregnant women are required to start folic acid supplements months before conception up until first trimester. Research is also highlight the importance of trace elements including iron, zinc, magnesium, selenium, iodine, and copper in pregnancy progression and fetal development (10-17). Also Vitamin D has gained a lot of attention for its role in pregnancy, its deficiency has been linked to antenatal complications such as gestational hypertension, low birth weight, skeletal development and growth for the baby (18).

One of the greatest unrecognized nutrients are the essential fatty acids. The typical Western diet is deficient in the “anti-inflammatory” omega-3 fatty acids, found in fatty fish, but abundant in the “pro-inflammatory” monounsaturated and saturated fatty acids found in salty and sweet snacks, white bread, desserts, processed meat products. This, in turn, increases the inflammatory state, which has been closely linked to preterm birth (19, 20).

In fact, I am fortunate enough to closely work under the supervision of Professor Michael Crawford, one of Borne’s research team collaborators, whose early works showed that the human brain is made up of long chain polyunsaturated fatty acids and requires omega-3 and omega-6 fatty acids for its development. His research has highlighted the indispensable role of essential fatty acids, not only in ensuring a healthy pregnancy but also in preventing neurodevelopmental disorders related to improper brain development in utero such as cerebral palsy (21-23).

What should expectant mothers be eating, what should they be avoiding?

A balanced diet is crucial when it comes to pregnancy, and ideally should start prior to conception. Expectant mothers should focus on a nutrient rich diet, with fruits and vegetables for their high antioxidant content, different types of fish and seafood for their omega-3 fatty acids, zinc, and iodine content. In fact, the joint export report of the World Health Organisation and Food and Agriculture Organisation 2008-2010 (Nutrition report no 91, FAO, Rome) recommends 200mg DHA/day or 250mg/day of DHA +EPA during pregnancy.  DHA and EPA are the core omega-3 fatty acids.

Women should also eat whole grains for protein and phosphorous, chicken, meat, and eggs for their omega-6 fatty acid content. Ideally, pregnant women should reduce their intake of processed foods, foods high in salt and refined sugars that are energy dense but nutrient poor. Although developing hypertension or diabetes during pregnancy is a result of interplay of factors, diet has still an important role in the prevention of adverse pregnancy outcomes. Smoking should be avoided and alcohol in very limited amounts as consumption of both has been linked to pregnancy complications (24, 25).

There are lots of myths out there regarding nutrition and pregnancy – what advice would you give to expectant mothers?

The National Institute for Health and Care Excellence (NICE) provides national evidence based guidance for pregnant women, this can be accessed online.

Alternatively, the World Health Organisation shares a lot of guidelines for nutrition in pregnancy. The WHO offers evidence-informed recommendations for pregnant women in general. In addition, the NHS website also provides some clear guidelines around pregnancy and the health of both mother and baby.

There are some myths with regards to nutrition in pregnancy such as “eating for two”. The women should have a rich, balanced diet that ensures proper intake of vitamins and nutrients. New guidelines on woman’s caloric intake indicate a 200-calorie increase in the last three months of pregnancy. It is crucial to test for nutritional deficiencies such as Iron or Vitamin D and to get the necessary supplementation.

If a mother decides to breastfeed, is their diet still important?

Absolutely. Breast milk is most natural, nutritional and safe food a mother can offer her baby. It provides the baby with essential fatty acids and nutrients he requires and is also beneficial for the mother as it may reduce the risk of breast and cervical cancer. It is important for the mother to sustain her healthy diet during breastfeeding stage as it influences the human milk composition and potentially the growth of the baby.

Why is research so important when it comes to nutrition and pregnancy?

The curve of preterm birth is increasing. With a recent shift in western diet, focused heavily on processed and refined foods, we need to do more to see if this is having a direct impact on preterm birth rates. We are in the process of finalising a new study, which will look at the importance of maternal fatty acids profiles in the early stages of pregnancy and relate it to pregnancy complications – diabetes, preeclampsia, preterm birth, and baby growth and development.

We ultimately need to understand more and be in a position to educate mothers prior to conception so they enter their pregnancy healthy and aware of what they can do for the health of their baby.

The research team at Imperial College London will be launching a new prospective study recruiting a 1000 women pregnancy and relating their fatty acid profile to pregnancy complications. This will complement the trial which was conducted by Dr Enitan Ogundipe and both Professors Mark Johnson and Michael Crawford which implied the importance of essential fatty acids in pregnancy and in the months prior to conception (26). The study will be sponsored by Borne and the Little Foundation and will hopefully help us confirm the crucial role essential fatty acids play in maintaining a healthy pregnancy.

References:
  1. Barker DJ. The fetal and infant origins of adult disease. Bmj. 1990;301:1111.
  2. Blencowe H, Cousens S, Chou D, et al. Born too soon: the global epidemiology of 15 million preterm births. Reprod Health. 2013;10 Suppl 1:S2.
  3. Popkin BM, Adair LS, Ng SW. Global nutrition transition and the pandemic of obesity in developing countries. Nutr Rev. 2012;70:3-21.
  4. Grieger JA, Grzeskowiak LE, Clifton VL. Preconception dietary patterns in human pregnancies are associated with preterm delivery. J Nutr. 2014;144:1075-80.
  5. Han Z, Mulla S, Beyene J, Liao G, McDonald SD. Maternal underweight and the risk of preterm birth and low birth weight: a systematic review and meta-analyses. Int J Epidemiol. 2011;40:65-101.
  6. Chu SY, Callaghan WM, Kim SY, et al. Maternal obesity and risk of gestational diabetes mellitus. Diabetes care. 2007;30:2070-6.
  7. Gillman MW, Rifas-Shiman S, Berkey CS, Field AE, Colditz GA. Maternal gestational diabetes, birth weight, and adolescent obesity. Pediatrics. 2003;111:e221-6.
  8. Rosenberg TJ, Garbers S, Lipkind H, Chiasson MA. Maternal obesity and diabetes as risk factors for adverse pregnancy outcomes: differences among 4 racial/ethnic groups. American journal of public health. 2005;95:1545-51.
  9. Sebire NJ, Jolly M, Harris J, et al. Maternal obesity and pregnancy outcome: a study of 287 213 pregnancies in London. International Journal of Obesity & Related Metabolic Disorders. 2001;25.
  10. Bath SC, Steer CD, Golding J, Emmett P, Rayman MP. Effect of inadequate iodine status in UK pregnant women on cognitive outcomes in their children: results from the Avon Longitudinal Study of Parents and Children (ALSPAC). The Lancet.382:331-7.
  11. Danesh A, Janghorbani M, Mohammadi B. Effects of zinc supplementation during pregnancy on pregnancy outcome in women with history of preterm delivery: a double-blind randomized, placebo-controlled trial. J Matern Fetal Neonatal Med. 2010;23:403-8.
  12. Kiilholma P, Gronroos M, Erkkola R, Pakarinen P, Nanto V. The role of calcium, copper, iron and zinc in preterm delivery and premature rupture of fetal membranes. Gynecol Obstet Invest. 1984;17:194-201.
  13. Okunade KS, Oluwole AA, Adegbesan-Omilabu MA. A Study on the Association between Low Maternal Serum Magnesium Level and Preterm Labour. Advances in Medicine. 2014;2014:6.
  14. Pathak P, Kapil U. Role of trace elements zinc, copper and magnesium during pregnancy and its outcome. The Indian Journal of Pediatrics. 2004;71:1003-5.
  15. Rayman MP, Wijnen H, Vader H, Kooistra L, Pop V. Maternal selenium status during early gestation and risk for preterm birth. Cmaj. 2011;183:549-55.
  16. Scholl TO, Hediger ML, Schall JI, Fischer RL, Khoo CS. Low zinc intake during pregnancy: its association with preterm and very preterm delivery. Am J Epidemiol. 1993;137:1115-24.
  17. Tsuzuki S, Morimoto N, Hosokawa S, Matsushita T. Associations of maternal and neonatal serum trace element concentrations with neonatal birth weight. PLoS One. 2013;8:e75627.
  18. Qin LL, Lu FG, Yang SH, Xu HL, Luo BA. Does Maternal Vitamin D Deficiency Increase the Risk of Preterm Birth: A Meta-Analysis of Observational Studies. Nutrients. 2016;8.
  19. Endres S, Ghorbani R, Kelley VE, et al. The effect of dietary supplementation with n-3 polyunsaturated fatty acids on the synthesis of interleukin-1 and tumor necrosis factor by mononuclear cells. N Engl J Med. 1989;320:265-71.
  20. Olsen SF, Hansen HS, Sorensen TI, et al. Intake of marine fat, rich in (n-3)-polyunsaturated fatty acids, may increase birthweight by prolonging gestation. Lancet. 1986;2:367-9.
  21. Crawford M. Placental delivery of arachidonic and docosahexaenoic acids: implications for the lipid nutrition of preterm infants. The American Journal of Clinical Nutrition. 2000;71:275S-84S.
  22. Crawford MA, Casperd NM, Sinclair AJ. The long chain metabolites of linoleic avid linolenic acids in liver and brain in herbivores and carnivores. Comp Biochem Physiol B. 1976;54:395-401.
  23. Crawford MA, Hassam AG, Williams G. Essential fatty acids and fetal brain growth. Lancet. 1976;1:452-3.
  24. Albertsen K, Andersen AM, Olsen J, Gronbaek M. Alcohol consumption during pregnancy and the risk of preterm delivery. Am J Epidemiol. 2004;159:155-61.
  25. Wisborg K, Henriksen TB, Hedegaard M, Secher NJ. Smoking during pregnancy and preterm birth. Br J Obstet Gynaecol. 1996;103:800-5.
  26. Ogundipe E, Johnson M, Wang Y, Crawford MA. Does maternal lipid nutrition prior to conception predict preterm delivery and low birthweight. 2015.

 


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