Pregnancy provides a unique and critical window of opportunity to implement healthy dietary habits, and balanced maternal nutrition during pregnancy is important not only for the health of the mother but also to provide the right environment for optimal development of the baby. Nutritional status of the mother at conception and during pregnancy can also determine, at least in part, the risk to the foetus of developing disease in later life. In the absence of adequate nutrition, the foetus will ensure preservation by limiting growth, which results in an infant with a higher insulin response to food and less growth of muscle (including the heart), nephrons and bones.
Through infancy and childhood, when the diet improves, the individual will be prone to gaining weight and be at a higher risk of type 2 diabetes and metabolic syndrome, with an increased risk of cardiovascular disease in adulthood. There is also evidence that in low nutrient states, the placenta may limit what is available to the foetus to help preserve the health of the mother.1
The importance of nutrients
Ensuring optimal intake of all nutrients is essential but there should be specific focus on several key nutrients to help to support the health of both mother and baby.
This water-soluble B vitamin is a methyl donor required for DNA synthesis and cell division and is essential for the formation of the brain and spinal cord. The neural tube, from which the brain and spinal cord are formed, closes within 28 days of gestation and if it does not close completely, an opening at the lower end of the spine can cause spina bifida, whereas a larger defect can lead to anencephaly (complete failure of the brain to develop). Folate is required for neural tube development and its role in the prevention of neural tube defects (NTDs) is well established. 1
In individuals with relatively common MTHFR gene defects, thought to occur in around 30-40% of the population, data suggests that prenatal supplementation with the active L-methylfolate is more successful at increasing bioavailable folate concentrations than unmethylated folic acid. L-methylfolate bypasses the MTHFR gene pathways and is therefore bioavailable when gene efficiency is otherwise compromised.2
Foods rich in folate include beans, peas, orange juice, and green leafy vegetables
Requirements during pregnancy are increased due to a 50% increase in maternal thyroid hormone production. Thyroid stimulating hormone is not synthesised in the foetus until around the 10th-12th week of gestation, around the same time that the foetal thyroid begins to be able to concentrate iodine and produce the thyroid hormones triiodothyronine (T3) and thyroxine (T4) – although there is very little thyroid hormone synthesis until the 18th-20th week of gestation. As a result, in the first half of pregnancy the foetus relies heavily on the mother for the thyroid hormones, and if maternal iodine is deficient thyroid production may be inefficient.1
Thyroid hormones regulate a wide range of cellular and physiological functions and are essential for normal child growth and development. Dietary iodine is rapidly absorbed, and the thyroid gland is dependent on a regular and adequate supply in order to produce thyroid hormones. In the foetal brain, inadequate thyroid hormone levels impair differentiation, maturation, cell migration and myelination. Critically low levels of thyroid hormones, associated with severe iodine deficiency cause neurological damage to the brain, particularly during the foetal and neonatal period, which can result in delayed motor and mental development, and even mild to moderate deficiency may result in impaired mental development.3
Vitamin D deficiency is considered a worldwide public health problem, and in most countries, large parts of the general population do not meet the dietary requirements. Although its role in musculoskeletal health and the prevention of conditions such as rickets and osteomalacia is well documented, accumulating data suggests it may also play an important role in pregnancy outcomes.4
One reason to ensure adequate Vitamin D status in pregnancy is that it is necessary to ensure appropriate maternal response to the demands of calcium for the foetal bone mineral accretion. Around 25-30g of calcium are transferred to the foetal skeleton during pregnancy, which equates to approximately 250mg/day in the third trimester.8 Evidence suggests vitamin D supplementation may also help to protect against pregnancy complications such as preclampsia, gestational diabetes, the need for caesarean section birth and postnatal depression. Immunity and allergies, and particularly respiratory infections are also thought to be more common in the offspring of mothers deficient in vitamin D. 5
Supplementing with levels of up to 4000IU D3 daily during pregnancy is considered safe and beneficial. 6
Major dietary sources of vitamin D are fatty fish (salmon), egg yolks, fortified milk, margarine, yogurt, and orange juice – however it is estimated that around 80% of vitamin D supply is derived from endogenous production in the skin after exposure to ultraviolet-B light.4
Food sources of calcium are milk, yogurt, cheese, fortified juices, tofu, cereals, Chinese cabbage, kale, broccoli, and fish with bones.
Optimal levels of other nutrients, including vitamin A, B12, magnesium, selenium and zinc also play important roles in supporting a healthy pregnancy, so a balanced pregnancy multivitamin is recommended.
Omega 3 Fatty Acids
The importance of Omega-3 long chain polyunsaturated fatty acids (PUFA) in pregnancy was first observed in the 1980s, where a diet high in oily fish, as consumed by the Faroe Islanders was linked to longer gestation, higher birthweight and less preterm birth when compared with the Danish population.7 The PUFA docosahexaenoic acid (DHA) provides the building blocks for foetal retinal and brain cells, and its incorporation into the cell membrane influences the stability, fluidity and function of many cell types through its effects on gene expression and tissue differentiation. Omega 3 fatty acids play crucial roles during foetal growth and development, and higher intakes have been associated with decreased maternal depression, reduce rates of intrauterine growth restriction and improved neurocognitive outcomes in the offspring.8
Although some endogenous synthesis of DHA from dietary fatty acid precursors EPA and ALA can occur, the primary source of foetal and infant DHA is from maternal intake. In the third trimester, maternal DHA stores are mobilised and placental transfer of DHA is preferential to other fatty acids, and the DHA accumulation in the brain at this time is substantially higher than the overall body deposition rates.9
While fish and seafood are the richest dietary sources of DHA, the NHS advise eating no more than two portions of oily fish per week, due to the risk that the heavy metals, dioxins and polychlorinated biphenyls commonly found in fish can pose to the baby.10 Methylmercury is present in all fish tissues, cannot be cooked out of the fish and over 95% is absorbed by the body. If transferred to the foetus, it can cause widespread neurological damage – in fact, the foetal brain is considered the tissue most vulnerable to the harms of mercury.11 For this reason, as well as personal preference, many expectant mothers are reluctant to increase their oily fish intake and will benefit from taking an Omega 3 supplement rich in DHA.12
The old adage “eating for two” is not a true mathematical representation of the 10-25% increase in caloric intake actually needed to support appropriate maternal weight gain in the later stages of pregnancy. In fact, given that many individuals consume over the recommended level of calories, the emphasis should not be to increase calories in pregnancy, but to ensure a shift from low-nutritional calories to nutrient dense calories. Aside from increased weight gain, the overconsumption of calories in pregnancy can increase the risk of hypertension in the mother, gestational diabetes, macrosomia (high birthweight baby) and childhood obesity in the offspring. Likewise, an inadequate energy intake is associated with low-birth-weight babies and an increased risk of adult metabolic diseases in the offspring, as discussed earlier.1
Potential Pregnancy Complications
Gestational Diabetes Mellitus
Gestational diabetes mellitus (GDM), defined as a glucose intolerance which is first recognized during pregnancy, is a metabolic and endocrine disorder and occurs when the pancreatic function in the pregnant mother is not sufficient to overcome the diabetic condition of pregnancy. During gestation in all pregnancies, insulin resistance increases progressively and reaches a peak in the third trimester, and in normal pregnancies the beta cells of the pancreas produce higher levels of insulin, thus preventing hyperglycaemia. Conversely, in GDM the response of the beta cells in insufficient and hyperglycemia occurs. One of the most common pregnancy complications, it is considered as pre-diabetic and is one of the predictors of future type 2 diabetes in both the mother and children from these pregnancies.13 Associated with several adverse maternal and neonatal outcomes, such as pre-eclampsia, caesarean delivery, fetal macrosomia and neonatal hypoglycemia, GDM is an increasing public health concern that affects around 10% of pregnancies and is rising in prevalence, in part due to the current phenomenon of high-calorie malnutrition brought on by the increased reliance on processed foods.
Nutritional Therapy is typically the first-line approach in managing GDM and the Mediterranean diet, typified by high intake of vegetarian foods (such as whole grains, fruits, vegetables) and fish, and the low intake of processed animal and fatty foods has been associated with a lower incidence of GDM as well as improved glucose tolerance in pregnant women without the condition.14
Vitamin D has been shown to increase insulin tolerance through a number of mechanisms and decrease insulin resistance in both type 2 diabetes patients and healthy subjects. Studies have also shown that vitamin D supplementation in the first and second trimester is effective at reducing the risk of glucose intolerance and developing GDM later in pregnancy.15
The Microbiome and GDM
There has long been increasing evidence that the gut microbiome plays a pivotal role in the progression of conditions such as metabolic syndrome and type 2 diabetes through its modulation of insulin signalling and inflammation. Accruing studies identify that alterations to microbiome during pregnancy can be a significant catalyst to the development of gestational diabetes. Even during a healthy pregnancy there are profound hormonal, immunological, and metabolic changes which take place above all during the third trimester to promote maternal weight gain, increasing circulating pro-inflammatory cytokines, and insulin resistance. These changes are thought to promote foetal growth and nutrient intake. However, in GDM there are more significant alterations in gut flora composition which over promote and tip the balance towards metabolic dysfunction and accentuating insulin resistance.
A highly diverse diet with high amounts of fibre along with poly unsaturated fatty acids, particularly omega 3s, have been associated with greater microbial diversity in the gut. These diverse profiles of gut flora are more associated with those of women who have a healthy pregnancy as opposed to GDM. Therefore, it is suggested that modulation of the gut flora via dietary interventions may be an appropriate intervention for GDM and is an important factor to consider when looking at dietary intake of expectant mothers. 16
This small sugar molecule, considered part of the B Vitamin family has been much researched in relation to its role in improving insulin sensitivity in polycystic ovary syndrome as well as improving oocyte quality and outcomes of assisted reproduction.17 Evidence suggests that myo-inositol may also play a role in the development of the embryo. As phosphatidylinositol, it plays a role in the closure of the neural tube, and in mothers with a history of neural tube defects, when taken alongside folic acid has been shown to reduce risk greater than folic acid taken alone.18
Preeclampsia is identified as high blood pressure and proteinuria during pregnancy. It is becoming an increasingly common diagnosis in the developed world and remains a high cause of maternal and foetal morbidity and mortality in the developing world. Delay in childbearing in the developed world feeds into the risk factors associated with preeclampsia, which include older maternal age, obesity, and/or vascular diseases. The pathogenesis of pre-eclampsia is unknown but is associated with high blood pressure, oxidative stress, insulin resistance and poor cardiovascular markers. Therefore, factors looking at GDM as well as overall health in pregnancy are helpful in protecting against preeclampsia.1
Both GDM and preeclampsia are associated with altered maternal omega-3 status, altered placental omega-3 metabolism, reduced cord blood omega-3 levels and have an impact on neurodevelopment in the infant and on brain health later in life. These findings indicate lower DHA exposure of the developing baby may be driven by lower placental transfer in both conditions. Thus, determining approaches which facilitate increased delivery of DHA during pregnancy and early development might positively impact brain development in infants born to mothers with these diseases.20
As mentioned above, even in a healthy pregnancy there are many effects on digestive function. It has been seen that there are changes to the microbiome but also it is known that pregnancy increases the permeability of the digestive lining (leaky gut), which can lead to food intolerances, digestive disturbances and well as increased inflammation21. In addition, in the final trimester, the baby takes up additional space and can reduce stomach capacity, increasing symptoms such as heartburn and reflux. Also affected during pregnancy is the gallbladder, which enlarges and empties sluggishly in response to meals during pregnancy. Small intestinal transit is slowed, and the resting pressure of the lower oesophageal sphincter is reduced, this can additionally contribute to constipation, bloating and reflux. All of the above can therefore lead to uncomfortable gastrointestinal symptoms during pregnancy.
Therefore, supporting the health of the gut is essential, however many interventions that may be used outside of pregnancy are not appropriate for pregnant women. Things that can help include:
- Eating little and often- to reduce pressure on digetsive system and help ameliorate heartburn and reflux
- Including high fibre foods and omega 3 fatty acids to support the microbiome (also consider a probiotic (below)
- Consider supplementing with 200mg elemental magnesium, magnesium aids smooth muscle relaxation and therefore can encourage peristalsis.
- Consume lemon and hot water to stimulate bile production
Many studies have identified a link between healthy gut flora in the mother and the health of the baby. A healthy maternal gut flora has been linked to reduced inflammation, asthma, eczema, and coeliac disease risk, as well as improved immune function. The main reason for this is that during a natural birth the child will pass through the birth canal and pick up flora from the mother. As it does so, the bacteria will inoculate the child’s sterile gut. This flora will also be passed onto the child through colostrum during the first breast feed. If the mother therefore has a healthy balance of gut flora, this is reflected in the child. Because of its resilience, early colonisation of the infant gut by microbes sets the stage for the lifelong relatively stable adult microbiome, and pregnancy offers a window of opportunity for the microbiota shaping of the newborn.22 Probiotic use has been deemed safe during pregnancy and is associated with a reduced risk of atopic conditions and a more resilience to infection.
Nausea and vomiting during pregnancy can often be associated with low blood sugar, therefore maintaining healthy blood sugar regulation as described above can be very helpful. It has been suggested to have something by the side of your bed (preferably high in fibre and protein such as nuts/seeds) to eat before your feet touch the floor can be extremely supportive. Some women still struggle significantly even if they follow these interventions, constant nausea can also exacerbate low blood sugar due to the inability to eat. Choline bitartrate and vitamin B6 have been shown to be useful for ameliorating symptoms of morning sickness. Other interventions such as ginger tea can be a useful addition.
Insomnia and sleep deficiency in pregnancy are very common with most women reporting sleep disturbances during pregnancy. Insomnia and sleep deficiency are also more prevalent as pregnancy progresses, possibly related to pregnancy-related physical symptoms or discomfort. There is increasing evidence indicating that these sleep problems may be associated with adverse maternal and fetal outcomes such as depressive symptoms, increased pain during labor, more Caesarean sections, preterm birth, and low birth weight.23
Therefore, supporting healthy sleep in pregnancy is essential the following can be useful:
- Nutrients including B6 and magnesium are essential cofactors in the synthesis of serotonin, the precursor to our sleep neurotransmitter melatonin.
- Practices of good sleep hygiene can be very useful (see our blog: Sleep: The impact of poor sleep & interventions for support | Cytoplan blog for tips for good sleep hygiene)
- Support the gut (again!!), gut flora are responsible for the production of 90% of serotonin and communicate with the brain via the vagus nerve via production of these as well a s short chain fatty acids. Also, digestive disturbances can contribute to poor sleep.
- Practice pregnancy exercises, yoga, Pilates, massage etc. to ensure good alignment and maintain muscle and joint health to prevent discomfort during night.
Stress and mood
It is also important to manage stress and mood. Insomnia and depression often come hand in hand and can both be exacerbated by stress. Perinatal depression increases the risk of postpartum depression and is linked to adverse cognitive issues in the baby. Utlising the above practices for sleep can also have a positive influence on mood.24
Stress during pregnancy has been shown to increase the risk of emotional disorders in children including ADHD, anxiety, depression, as well as schizophrenia in adulthood. It also increases the mother’s risk of postnatal depression. As stress and anxiety can tend to increase during pregnancy due to apprehension and potential health concerns, it is important to begin to manage stress before pregnancy.
Some stress relieving strategies are:
- Take a walk outside – studies have shown this reduces cortisol levels.
- Try mindful meditation – many apps are available to help you with this.
- Get adequate sleep see above
- Get sufficient magnesium – magnesium is known as nature’s tranquiliser, it has a calming effect and supports normal nervous system function. Consume dark leafy green vegetables and consider a supplement (200-400mg/day). You can also try a bath with 2 handfuls of Epsom salts, which are high in magnesium sulphate and can be absorbed through the skin to aid sleep and relaxation.
- Ensuring optimal intake of all nutrients is essential but there should be specific focus on several key nutrients will help to support the health of both mother and baby. Nutrients of particular importance are folate, iodine, vitamin D and omega 3 fatty acids.
- Also essential are Vitamin A, zinc, selenium, B12 and magnesium, therefore a balance pregnancy multivitamin is recommended.
- The old adage “eating for two” is not a true mathematical representation of the 10-25% increase in caloric intake actually needed to support appropriate maternal weight gain in pregnancy. In fact, given that many individuals consume over the recommended level of calories, the emphasis should not be to increase calories in pregnancy, but to ensure a shift from low-nutritional calories to nutrient dense calories.
- Gestational diabetes and pre-eclampsia are both serious complications of pregnancy and can presdipose the baby to conditions during its life. A low GL Mediterranean diet, supporting gut flora with fibre and probiotics as well as ensuring adequate omega 3 intake are all associated with a reduced risk of both of these conditions.
- A healthy maternal gut flora has been linked to reduced inflammation, asthma, eczema, and coeliac disease risk, as well as improved immune function. Probiotic use has been deemed safe during pregnancy and is associated with a reduced risk of atopic conditions and a more resilience to infection.
- Insomnia and sleep deficiency in pregnancy are very common with most women reporting sleep disturbances during pregnancy. Therefore supporting healthy sleep, with good sleep hygiene, relaxation techniques, activity and balanced nutrition is important.
- Choline bitartrate and vitamin B6 have been shown to be useful for ameliorating symptoms of morning sickness. Other interventions such as ginger tea can be a useful addition.
- Stress during pregnancy has been shown to increase the risk of emotional disorders in children including ADHD, anxiety, depression, as well as schizophrenia in adulthood. It also increases the mother’s risk of postnatal depression. As stress and anxiety can tend to increase during pregnancy due to apprehension and potential health concerns, it is important to begin to manage stress before pregnancy.
If you have questions regarding the topics that have been raised, or any other health matters, please do contact our team of Nutritional Therapists.
- Lowensohn RI, Stadler DD, Naze C. Current Concepts of Maternal Nutrition. Obstet Gynecol Surv. 2016;71(7):413-426. doi:10.1097/OGX.0000000000000329
- Servy EJ, Jacquesson-Fournols L, Cohen M, Menezo YJR. MTHFR isoform carriers. 5-MTHF (5-methyl tetrahydrofolate) vs folic acid: a key to pregnancy outcome: a case series. J Assist Reprod Genet. 2018;35(8):1431-1435. doi:10.1007/s10815-018-1225-2
- Markhus MW, Dahl L, Moe V, et al. Maternal Iodine Status is Associated with Offspring Language Skills in Infancy and Toddlerhood. Nutrients. 2018;10(9):1270. Published 2018 Sep 9. doi:10.3390/nu10091270
- Pilz S, Zittermann A, Obeid R, et al. The Role of Vitamin D in Fertility and during Pregnancy and Lactation: A Review of Clinical Data. Int J Environ Res Public Health. 2018;15(10):2241. Published 2018 Oct 12. doi:10.3390/ijerph15102241
- Agarwal S, Kovilam O, Agrawal DK. Vitamin D and its impact on maternal-fetal outcomes in pregnancy: A critical review. Crit Rev Food Sci Nutr. 2018;58(5):755-769. doi:10.1080/10408398.2016.1220915
- Wagner CL, McNeil RB, Johnson DD, Hulsey TC, Ebeling M, Robinson C, Hamilton SA, Hollis BW. Health characteristics and outcomes of two randomized vitamin D supplementation trials during pregnancy: a combined analysis. J Steroid Biochem Mol Biol. 2013 Jul;136:313-20. doi: 10.1016/j.jsbmb.2013.01.002. Epub 2013 Jan 10. PMID: 23314242; PMCID: PMC4365419.
- Olsen SF, Joensen HD. High liveborn birth weights in the Faroes: a comparison between birth weights in the Faroes and in Denmark. J Epidemiol Community Health. 1985;39(1):27-32. doi:10.1136/jech.39.1.27
- Emmett PM, Jones LR, Golding J. Pregnancy diet and associated outcomes in the Avon Longitudinal Study of Parents and Children. Nutr Rev. 2015;73 Suppl 3(Suppl 3):154-174. doi:10.1093/nutrit/nuv053
- Lauritzen L, Brambilla P, Mazzocchi A, Harsløf LB, Ciappolino V, Agostoni C. DHA Effects in Brain Development and Function. Nutrients. 2016;8(1):6. Published 2016 Jan 4. doi:10.3390/nu8010006
- Pregnancy – NHS (www.nhs.uk)
- Oken E. Fish consumption and docosahexaenoic acid (DHA) supplementation in pregnancy. UpToDate (www.uptodate.com)
- Middleton P, Gomersall JC, Gould JF, Shepherd E, Olsen SF, Makrides M. Omega-3 fatty acid addition during pregnancy. Cochrane Database Syst Rev. 2018;11(11):CD003402. Published 2018 Nov 15. doi:10.1002/14651858.CD003402.pub3
- Dolatkhah N, Hajifaraji M, Shakouri SK. Nutrition Therapy in Managing Pregnant Women With Gestational Diabetes Mellitus: A Literature Review. J Family Reprod Health. 2018;12(2):57-72.
- Karamanos B, Thanopoulou A, Anastasiou E, Assaad-Khalil S, Albache N, Bachaoui M, Slama CB, El Ghomari H, Jotic A, Lalic N, Lapolla A, Saab C, Marre M, Vassallo J, Savona-Ventura C; MGSD-GDM Study Group. Relation of the Mediterranean diet with the incidence of gestational diabetes. Eur J Clin Nutr. 2014 Jan;68(1):8-13. doi: 10.1038/ejcn.2013.177. Epub 2013 Oct 2. PMID: 24084515.
- Shahgheibi S, Farhadifar F, Pouya B. The effect of vitamin D supplementation on gestational diabetes in high-risk women: Results from a randomized placebo-controlled trial. J Res Med Sci. 2016;21:2. Published 2016 Jan 28. doi:10.4103/1735-1995.175148
- Ponzo V, Fedele D, Goitre I, et al. Diet-Gut Microbiota Interactions and Gestational Diabetes Mellitus (GDM). Nutrients. 2019;11(2):330. Published 2019 Feb 3. doi:10.3390/nu11020330
- Zheng X, Lin D, Zhang Y, Lin Y, Song J, Li S, Sun Y. Inositol supplement improves clinical pregnancy rate in infertile women undergoing ovulation induction for ICSI or IVF-ET. Medicine (Baltimore). 2017 Dec;96(49):e8842. doi: 10.1097/MD.0000000000008842. PMID: 29245250; PMCID: PMC5728865.
- Greene ND, Leung KY, Copp AJ. Inositol, neural tube closure and the prevention of neural tube defects. Birth Defects Res. 2017 Jan 30;109(2):68-80. doi: 10.1002/bdra.23533. PMID: 27324558; PMCID: PMC5353661.
- Phipps E, Prasanna D, Brima W, Jim B. Preeclampsia: Updates in Pathogenesis, Definitions, and Guidelines. Clinical Journal of the American Society of Nephrology : CJASN. 2016;11(6):1102. doi:10.2215/CJN.12081115
- Devarshi PP, Grant RW, Ikonte CJ, Mitmesser SH. Maternal Omega-3 Nutrition, Placental Transfer and Fetal Brain Development in Gestational Diabetes and Preeclampsia. Nutrients. 2019;11(5). doi:10.3390/NU11051107
- Camilleri M. The Leaky Gut: Mechanisms, Measurement and Clinical Implications in Humans. Gut. 2019;68(8):1516. doi:10.1136/GUTJNL-2019-318427
- Sohn K, Underwood MA. Prenatal and postnatal administration of prebiotics and probiotics. Semin Fetal Neonatal Med. 2017;22(5):284-289. doi:10.1016/J.SINY.2017.07.002
- Reichner CA. Insomnia and sleep deficiency in pregnancy. Obstet Med. 2015;8(4):168-171. doi:10.1177/1753495X15600572
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Last updated on 28th July 2022 by cytoffice