Chapter 1: Provide nutrition in pregnancy

Nutrition during pregnancy is a critical focus area for Nutrition and Dietetics professionals in Kenya, given the high burden of maternal and infant malnutrition in many communities. Proper nutritional support before and during pregnancy directly influences maternal health, fetal development, and birth outcomes. This chapter equips you with the knowledge to assess and address the unique nutritional requirements of women planning to conceive and throughout gestation, enabling improved health trajectories for mothers and their children.

1.1 Nutritional needs before and during pregnancy

A woman's nutrition before conception and through pregnancy shapes how the placenta forms, how the baby grows and how well she recovers after birth. A dietitian looks at three things together: what the woman needs, what she is eating and how her body is responding. This topic covers what changes in the body, why the preconception period matters, and the methods used to measure a woman's nutritional status and intake. The assessments here are the starting point for the intervention plan taught later in the chapter.

1.1.1 Introduction to nutrition before and during pregnancy

Nutrition before and during pregnancy covers the food and nutrient intake that supports the mother's changing body and the growth of the baby. Before conception, good nutrition supports regular ovulation and early development of the embryo. During pregnancy, the need for energy and most nutrients rises as blood volume expands, the uterus and breasts grow, the placenta forms and the baby gains tissue. A dietitian in an antenatal clinic or a community health unit therefore treats pregnancy as a period when the same woman needs a more nutrient-dense diet, not simply a larger one.

The timing and quality of nutrition support can influence birth weight, the length of the pregnancy and the mother's own health. For example, a woman who starts pregnancy with low iron stores may not be able to build the extra red blood cells she needs, even if she eats well from the first antenatal visit.

Nutritional changes before pregnancy

Before conception, nutritional status affects ovulation, implantation and early development of the baby's organs. A woman who is low in folate, iron or vitamin D, or who is very thin or very overweight, may find it harder to conceive and may face higher risks in early pregnancy. Preparing for pregnancy therefore means correcting anaemia, reaching a healthy body weight, taking folic acid and improving the variety of foods eaten.

Nutritional demands during pregnancy

Pregnancy brings physical changes that raise nutrient needs: a larger blood volume, a growing uterus, a developing placenta and the tissues of the baby. Energy needs rise gradually and are higher in the later months than in the first trimester. Protein needs rise to build maternal and fetal tissue. Iron, folate, iodine, zinc and calcium are needed in larger amounts, so the quality of each meal matters as much as its size. Appetite, nausea and food aversions change from one trimester to the next and affect what a woman can eat.

Impact of maternal nutrition on fetal development

The baby draws its nutrients from the mother's blood. When the mother's intake or stores are low, fetal growth may slow, which can lead to low birth weight. Shortages of specific nutrients affect specific organs: folate affects the neural tube in the first weeks, iodine affects the developing brain, and iron affects oxygen supply to the placenta. Well-balanced intake supports healthy placental function and brain growth, and lowers the risk of illness in the newborn.

Socioeconomic and cultural factors affecting nutrition

What a pregnant woman eats is shaped by income, food supply, workload, who controls household food decisions, and beliefs about food. Some families restrict certain foods in pregnancy, for example some fruits or fatty foods, for fear of a large baby or a difficult delivery. Others cannot afford a varied diet in the lean season. A dietitian listens first, then builds advice from foods the family already grows or can buy, so that the plan is realistic and respectful.

1.1.2 Importance of preconception nutrition

Many of the baby's organs begin forming in the first weeks after conception, often before a woman knows she is pregnant. Preconception nutrition therefore protects the baby at the stage when changes in diet cannot yet be made in response to a positive test. It also improves the mother's resilience through the demands of pregnancy and breastfeeding. A dietitian who sees women at a family planning clinic or a community outreach session has a chance to start this work early.

Reducing risk of neural tube defects

Folate is needed for the neural tube to close in the first weeks of pregnancy. Low folate intake before and during early pregnancy raises the risk of neural tube defects such as spina bifida. Women planning a pregnancy are advised to take folic acid supplements and to eat folate-rich foods such as dark green leafy vegetables, beans and fortified flours.

Correcting micronutrient deficiencies

Preconception is the time to correct iron, iodine and vitamin A deficiency, because each affects fertility and the baby's development. A woman who begins pregnancy with iron deficiency anaemia has a higher risk of delivering early or having a low birth weight baby, and is more likely to need treatment later in pregnancy.

Optimising maternal weight and body composition

Women who begin pregnancy underweight or overweight face a higher risk of complications such as pre-eclampsia and gestational diabetes. A dietitian can help a woman move towards a healthy body mass index (BMI) before conception through meal planning, activity advice and goals that she can keep up.

Enhancing fertility and pregnancy planning

Adequate nutrient intake supports hormone balance and regular ovulation. Both severe energy restriction and heavy excess can disturb cycles. Dietitians working with couples planning a pregnancy encourage varied meals built on whole grains, pulses, vegetables, fruit and animal-source foods where these are available.

Promoting healthy dietary behaviours

The preconception period is a good time to settle habits that will carry through pregnancy and breastfeeding: regular meals, diverse foods, less sugary drinks and fried snacks, and no alcohol or tobacco. Group sessions and home visits by community health promoters are practical ways to reach women who do not attend a clinic until the pregnancy is advanced.

1.1.3 Assessment of nutritional needs before and during pregnancy

Assessment is the process of finding out a woman's nutritional status and risks so that advice fits her. A dietitian combines four sources of information: body measurements, laboratory tests, a clinical examination and a record of what she eats. No single source is enough. For example, a woman with a normal weight may still be anaemic, and a woman with a poor recall may be eating better than she reports.

Using the results together

Results from the four sources are read side by side. A low haemoglobin with a diet low in iron-rich foods and a history of heavy periods points to a clear plan. A normal weight with high blood pressure points to a referral. The dietitian records the findings in the antenatal card or the nutrition register and shares them with the midwife or clinician.

1.1.3.1 Anthropometry

Anthropometry means measuring the body. In pregnancy it shows whether a woman started pregnancy underweight, normal or overweight, and whether she is gaining weight at a healthy rate. A dietitian uses weight, height, mid-upper arm circumference (MUAC) and body mass index.

Measuring a woman's weight and height:

1. Ask her to remove shoes, heavy clothing and bulky items from her pockets and to empty her bladder if she wishes.
2. Check that the scale is on a firm, level surface and reads zero before she steps on.
3. Ask her to stand still in the centre of the scale, looking straight ahead, and read the weight to 0.1 kg.
4. For height, ask her to stand with heels together and back against the rod, head level, and lower the headboard to the crown of her head.
5. Read the height to 0.1 cm and record both values on the card at once.
6. Ask for her usual weight before pregnancy or use the weight at the first visit if she came in the first trimester.

Measuring MUAC:

1. Ask the woman to expose her left upper arm and let it hang loosely.
2. Find the midpoint between the tip of the shoulder and the tip of the elbow with the arm bent at a right angle, and mark it.
3. Wrap the tape around the midpoint, snug but not tight, without squeezing the skin.
4. Read to the nearest millimetre and record. A cut-off such as 23 cm is used in several national guidelines and the cut-off differs between guidelines, so the facility's own cut-off is followed: a reading below it is a sign that a pregnant woman needs follow-up for undernutrition.

BMI is weight in kilograms divided by height in metres squared:

BMI = weight (kg) ÷ height (m)²

Worked example 1: a woman weighs 58 kg and is 1.60 m tall.

Height² = 1.60 × 1.60 = 2.56

BMI = 58 ÷ 2.56 = 22.66, rounded to 22.7 kg/m²

This is within the normal range of 18.5 to 24.9 kg/m².

Worked example 2: a woman weighs 47 kg and is 1.62 m tall.

Height² = 1.62 × 1.62 = 2.6244

BMI = 47 ÷ 2.6244 = 17.91, rounded to 17.9 kg/m²

This is below 18.5, so she is underweight and her weight gain target is higher.

The Institute of Medicine reference for total weight gain in a single pregnancy, by pre-pregnancy BMI, is used where a national chart is not available:

Worked example 3: a woman with a normal BMI weighs 63.0 kg at 13 weeks. At 24 weeks, 11 weeks later, the expected gain at 0.42 kg per week is 11 × 0.42 = 4.62 kg, so her expected weight is 63.0 + 4.62 = 67.6 kg. If the rate ranges from 0.35 to 0.50 kg per week, the expected range is 63.0 + 3.85 = 66.9 kg to 63.0 + 5.5 = 68.5 kg. A reading of 66.0 kg is below the range, so the dietitian asks about nausea, illness, appetite and meals, and discusses the finding with the midwife.

1.1.3.2 Biochemical assessments

Biochemical assessments use blood or urine tests to show nutrient stores and function that cannot be seen on the outside. A dietitian does not order the tests but asks the clinician for them, reads the results and uses them to shape advice.

The tests most used in pregnancy are:

• Haemoglobin: shows whether the woman is anaemic. It is measured in grams per decilitre (g/dL) from a finger-prick drop in a haemoglobinometer or from a venous sample in the laboratory.
• Serum ferritin: shows iron stores. A low ferritin means stores are depleted even before haemoglobin falls.
• Blood glucose: a fasting or oral glucose tolerance test is used to find gestational diabetes, as ordered by the clinician.
• Folate and vitamin B12: used when anaemia does not respond to iron or when the diet is very limited, for example in a woman who eats no animal-source foods.
• Urine protein dipstick: protein in the urine, with raised blood pressure, is a warning sign of pre-eclampsia and goes to the clinician at once.
• Urinary iodine: used in surveys to judge whether a group of pregnant women has enough iodine. It is not a test for one woman.

The WHO thresholds for anaemia in pregnancy are:

Within anaemia, the WHO severity bands for pregnant women are: in the first and third trimesters mild 10.0 to 10.9 g/dL, moderate 7.0 to 9.9 g/dL and severe below 7.0 g/dL; in the second trimester mild 9.5 to 10.4 g/dL, moderate 7.0 to 9.4 g/dL and severe below 7.0 g/dL. Severe anaemia needs urgent clinical care, not diet advice alone.

Finger-prick tests use single-use lancets and a new lancet for each woman. Used lancets and blood-stained swabs go straight into a sharps container and are never cleaned or reused.

1.1.3.3 Clinical monitoring

Clinical monitoring means looking at the woman's body and history for signs of nutrition problems and danger signs. It is done together with the midwife and clinician at each antenatal visit.

Things to check are:

• Blood pressure: raised blood pressure with swelling or protein in the urine needs urgent referral.
• Pallor: pale inner eyelids, palms or nail beds suggest anaemia and are checked against haemoglobin.
• Swelling: mild swelling of the feet is common, while swelling of the face and hands with headache needs referral.
• Signs of deficiency: a swollen neck (goitre), cracks at the corners of the mouth, a smooth sore tongue, dry rough skin and difficulty seeing in dim light suggest iodine, B vitamin or vitamin A problems.
• Nausea and vomiting: the frequency, the foods tolerated and any weight loss are recorded.
• Obstetric and medical history: earlier miscarriage, preterm birth, stillbirth, gestational diabetes or pre-eclampsia, chronic illness such as HIV, malaria or sickle cell disease, and medicines taken.

A woman with a history of preterm delivery or gestational diabetes needs closer follow-up. Danger signs such as severe headache with blurred vision, bleeding, reduced baby movements or severe pallor are never managed with food advice: the woman is referred at once.

1.1.3.4 Dietary assessments

Dietary assessment finds out what the woman eats, how often and how much, so intake can be compared with her needs. Several methods are used, and the choice depends on the time available and the purpose.

The main methods are:

• 24-hour recall: the woman describes everything eaten and drunk in the last 24 hours, in order. It is quick and works for women who cannot read.
• Food frequency questionnaire: a list of foods, each marked for how often it is eaten. It is useful for foods that are not eaten daily, such as meat, eggs, liver and fruit.
• Food diary: the woman records food and drink over three or more days. It is more accurate but needs literacy and effort.
• Diet history: an interview about usual meals, food preferences, cravings, aversions, cultural restrictions and supplement use.
• Dietary diversity score: counts food groups eaten in the day. For women, ten groups are used: grains and roots; pulses; nuts and seeds; dairy; meat, poultry and fish; eggs; dark green leafy vegetables; vitamin A-rich fruits and vegetables; other vegetables; and other fruits. A group counts only if at least 15 g was eaten, and five or more groups suggests a better chance of meeting micronutrient needs.

A 24-hour recall is done in steps so that nothing is forgotten:

1. Ask the woman to list quickly everything she ate and drank from waking yesterday to waking today.
2. Prompt for forgotten items: snacks, drinks, sweets, food from the market, tea with sugar.
3. Record the time and place of each meal and snack.
4. Ask for detail on each item: the cooking method, the amount in cups, spoons, handfuls or pieces, and brand if bought.
5. Use food models, cups and spoons to estimate portions.
6. Review the whole list with her and ask whether yesterday was a usual day.

Worked example 4: a woman reports boiled cassava for breakfast, rice with cowpeas for lunch and chapati with cabbage for supper. The food groups counted are grains, roots and tubers (one group), pulses and other vegetables, so the score is 3 out of 10. No animal-source food, dairy, egg, fruit or dark green leafy vegetable appears, so iron, zinc, vitamin A and folate are the nutrients to watch.

The weaknesses of recall methods are forgetting, under-reporting of food considered undesirable, and the fact that one day may not be typical. A dietitian reduces these by asking more than one recall, taking account of season and harvest, and asking without judging. Reported intakes are then compared with the reference intakes in the sections that follow.

1.1.3.4.1 Key nutritional needs

Nutrient needs are expressed in reference values: the estimated average requirement, which meets the need of half of a group, and the recommended dietary allowance, which meets the need of nearly everyone. Values are given in milligrams (mg) and micrograms (µg). Pregnancy raises the need for some nutrients far more than the need for energy, so each meal must be rich in nutrients.

The nutrients with their own sections that follow are iron, iodine, vitamin D, macronutrients, folic acid and zinc. Others that also need attention are:

• Calcium: needed for the baby's bones. Dairy products, small fish eaten with the bones, and dark green leafy vegetables are sources. Where the diet is low in calcium, a clinician may advise a calcium supplement, as taught under supplementation.
• Vitamin A: needed for vision and immunity. Orange-fleshed sweet potato, carrots, pumpkin, mango and dark green leafy vegetables supply it. High doses of preformed vitamin A (retinol) from supplements or from large amounts of liver are avoided in pregnancy because of a risk of birth defects.
• Vitamin B12: found naturally only in animal-source foods (and in fortified foods), so a woman who eats none of either needs a supplement, as advised by the clinician.
• Vitamin C: helps iron absorption. Oranges, guavas, tomatoes and green peppers supply it.
• Omega-3 fatty acids: needed for brain development. Fish, including small dried fish, supply them.

A planning step is to compare intake with reference values, mark nutrients that fall short and decide whether the gap can be filled by food, by fortified foods or by supplements.

1.1.3.4.2 Iron

Iron is needed to make the extra red blood cells of pregnancy and to supply the baby and placenta. The reference intake in pregnancy is about 27 mg per day (Institute of Medicine). WHO recommends daily oral iron with folic acid in pregnancy to prevent anaemia: 30 to 60 mg of elemental iron with 400 µg of folic acid.

Food sources are:

• Haem iron: liver, red meat, poultry and fish. It is absorbed better than iron from plants.
• Non-haem iron: beans, cowpeas, lentils, green leafy vegetables, millet and fortified flours.

Absorption of non-haem iron improves when vitamin C-rich foods such as tomatoes, oranges or guavas are eaten at the same meal. Tea, coffee and milk at a meal reduce it, as do the phytates in unrefined cereals. Soaking, fermenting and germinating grains and pulses reduces phytate. Cooking in iron pots can add small amounts of iron.

Assessment cues: ask how often meat, fish, liver or eggs are eaten, whether tea or coffee is taken with meals, and whether iron tablets are taken, when and with what. Low iron intake with heavy periods before pregnancy, short spacing between births or hookworm infection raises the risk of anaemia.

1.1.3.4.3 Iodine

Iodine is needed to make thyroid hormones, which direct the growth of the baby's brain. WHO recommends 250 µg per day in pregnancy. Deficiency in pregnancy can cause goitre in the mother and impaired brain development in the child, and it raises the risk of miscarriage.

Sources are iodised salt, fish and other seafood, milk and eggs. Where a household uses iodised salt, it is the main way to meet the need. Iodine is lost from salt stored open or exposed to heat and moisture, so salt is kept in a covered container and added near the end of cooking. Salt intake should still be moderate, so the woman is advised not to add more salt just to get iodine.

Assessment cues: ask whether the household buys iodised salt, how it is stored and when it is added to food, and whether fish or milk is eaten. A goitre found in the clinical examination is referred to the clinician.

1.1.3.4.4 Vitamin D

Vitamin D helps the body absorb calcium and supports the baby's bone growth. The reference intake in pregnancy is 15 µg (600 IU) per day (Institute of Medicine). WHO does not recommend routine vitamin D supplements for all pregnant women, but a clinician may give them to a woman with proven deficiency or little sun exposure.

The skin makes vitamin D in sunlight, so short, regular sun exposure of the face and arms supports it. The amount needed depends on skin colour, clothing, time of day and season. A woman who covers most of her body or spends the day indoors makes less. Food sources are oily fish, egg yolk, liver and fortified foods such as some edible oils.

Assessment cues: ask about time outdoors, clothing, intake of fish and eggs, and any bone pain or muscle weakness. Low vitamin D is checked with a blood test if the clinician orders it.

1.1.3.4.5 Macronutrients

Macronutrients are energy, protein, carbohydrate, fat and fibre. In pregnancy the extra energy needed is modest in the first trimester and larger later. A joint FAO, WHO and UNU expert consultation estimates additional energy of about 85, 285 and 475 kcal per day in the first, second and third trimesters for women who gain weight normally.

Worked example 5: a woman who needs 2,000 kcal per day before pregnancy needs about 2,000 + 85 = 2,085 kcal in the first trimester, 2,000 + 285 = 2,285 kcal in the second and 2,000 + 475 = 2,475 kcal in the third. The 2,000 kcal here is a hypothetical starting point and not a standard for every woman.

Protein builds the baby's tissue, the placenta and the mother's blood and breast tissue. The additional protein needed is about 1 g, 9 g and 31 g per day in the three trimesters. Good sources are beans, cowpeas, groundnuts, eggs, fish, milk, meat and poultry.

Carbohydrate supplies the baby's brain with glucose. The reference intake is 175 g per day. Whole grains, roots such as sweet potato and arrowroot, and plantain are sources. Fat is needed for the baby's brain and for the absorption of vitamins A, D, E and K. Sources include fish, groundnuts, avocado and vegetable oils. Fibre of about 28 g per day helps against constipation and comes from whole grains, pulses, vegetables and fruit.

1.1.3.4.6 Folic Acid

Folic acid is the synthetic form of folate. It is needed for cell division and for closing the neural tube. WHO recommends that women take 400 µg of folic acid daily from the time they try to conceive until 12 weeks of pregnancy. The reference intake over the whole of pregnancy is 600 µg of dietary folate equivalents (DFE) per day. A woman who has had a baby with a neural tube defect needs a higher dose that only a clinician prescribes.

Food sources of folate are dark green leafy vegetables, beans, cowpeas, liver, oranges and avocado. Natural folate is easily lost in cooking, so vegetables are cooked briefly. Fortified maize flour and wheat flour supply folic acid. Folic acid in supplements or fortified foods is absorbed better than folate from food, which is why dietary folate equivalents are used.

Assessment cues: ask whether the woman took folic acid before conception, whether she eats leafy vegetables and beans daily, and whether tablets are taken regularly. Because many pregnancies are not planned, women of reproductive age are encouraged to eat folate-rich foods at all times.

1.1.3.4.7 Zinc

Zinc is needed for cell growth, protein making and immunity. The reference intake in pregnancy is 11 mg per day (Institute of Medicine). Low zinc intake in pregnancy may be linked with poor fetal growth, although the evidence is mixed.

Sources are meat, fish, eggs, milk, beans, groundnuts and pumpkin seeds. Zinc from plant foods is absorbed poorly when the diet is high in phytate, as in unrefined maize, sorghum and millet. Soaking, fermenting and germinating grains and pulses improves absorption.

Assessment cues: ask how often meat, fish and eggs are eaten and whether the staple is mostly unrefined cereal. High-dose zinc supplements of more than 40 mg per day interfere with copper and are not given without a clinician's advice. The woman should not take zinc and iron tablets together unless the clinician has directed it, because they compete for absorption.

Chapter Summary

This chapter explores the nutritional needs before and during pregnancy, emphasizing the importance of adequate nutrition in the preconception period to support maternal and fetal health. It details various assessment methods including anthropometry, biochemical tests, clinical monitoring, and dietary evaluations to determine nutritional status. The discussion then shifts to common pregnancy-related complications such as gestational diabetes, anemia, pre-eclampsia, and mental health challenges that can impact maternal and infant outcomes. Developing a nutrition intervention plan involves systematic steps and incorporates supplementation, diet planning, deworming, and education to address identified nutritional gaps. The implementation process requires careful coordination, supported by appropriate tools and resources to ensure effective delivery. Monitoring and evaluation are crucial for tracking progress through repeated assessments and observations, using specific indicators to measure success. The chapter also highlights potential challenges encountered during monitoring and evaluation, underscoring the need for continuous improvement in nutrition interventions during pregnancy.