ABSTRACT.
Dietary iron and folate are nutrients of great importance during pregnancy because of the role they play to ensure optimal birth outcomes. Dietary intake has been found to decline during the third trimester. This study sought to assess the dietary iron and folate intake in the third trimester and pregnancy outcomes of women in their third trimester attending antenatal clinics at Korle-Bu Teaching Hospital. Eighty-one participants at a gestational age of 32 weeks were recruited and monitored until delivery—from May 4, 2020 to July 1 2020—using a consecutive sampling method at the Department of Obstetrics and Gynecology, Korle-Bu Teaching Hospital. Dietary intake information was obtained based on a 52-item quantitative food frequency questionnaire. Daily supplement doses of participants were recorded. Serum concentrations of iron (ferritin) and folate were determined using ELISA microwells. The mean dietary intake of iron and folate was 13.5 ± 8.30 mg and 331.0 ± 114.0 μg, respectively. The mean intake of iron and folic acid supplements was 42.7 ± 48.8 mg and 5.5 ± 11.1 mg, respectively. Most of the participants had serum ferritin and folate levels in the normal range (82.7% and 87.7%, respectively). Almost all the participants had positive birth outcomes, and total dietary iron was a significant predictor of birth outcome (P = 0.041). The majority of pregnant women did not meet the daily recommendation for iron and folate, but adherence to daily supplement intake was good and could have accounted for the positive birth outcomes.
INTRODUCTION
Pregnancy is marked with excitement in most sub-Saharan African cultures because it signifies an addition to the family as well as society at large. 1 As much as these expectant women are excited during this period, they also expect to give birth to healthy children and be in good health to cater for their newborns. However, this expectation is not always met because of a variety of factors, including poor maternal nutritional status, which results in undesirable maternal and child health indices in many of these communities. 2
During pregnancy, there are a lot of physiological changes that occur which require appropriate and balanced nutrition, which are part of the key elements of a healthy lifestyle to optimize both maternal and child health. 3 In the past, the primary concern of prenatal nutrition epidemiology was the effect of malnutrition and nutrition deficiencies, but the current literature is now increasingly interested in the overall quality of the maternal diet. 4 Optimal nutritional status of the expectant mother is essential in attaining optimal growth and development of the fetus. 4 Adequate intake of both macro- and micronutrients is needed during pregnancy. However, there is a relatively increased demand for micronutrients relative to macronutrients that results in increased micronutrient requirements. 5 Moreover, deficiencies in these micro nutrients have significant consequences on both the mother and the developing fetus, which is backed by the physiological role played by these minerals and vitamins. 6
Two micronutrients of special importance during pregnancy are iron and folate. 7 Iron is needed during pregnancy because it is a vital constituent of hemoglobin, which is essential for blood formation and oxygen supply. 7 Maternal anemia during pregnancy influences postnatal infant growth, and it is also associated with an increased risk for low birthweights and preterm births. 7 This emphasizes the importance of adequate iron status during gestation. Humans are born with approximately 270 mg of iron in their body. 5 The iron requirement during pregnancy is much greater than this value. 5 The total iron requirement during pregnancy (excluding loss at delivery) on average is approximately 835 mg for a singleton pregnancy; the recommended daily allowance (RDA) of iron during pregnancy is also 27 mg/d. 8 The World Health Organization (WHO) advocates for optimal iron intake from dietary sources and supplements with a daily oral iron supplementation of 30 to 60 mg. 9 Dietary folate also plays an important role during pregnancy as well as birth outcomes. 10 Nutritional deficiency of folate has been associated with low birthweights, premature births, and fetal malformations, among others. 10 Neural tube defect (NTD) is an example that falls under the umbrella of fetal malformations caused by the deficiency of maternal folate. This maternal folate is supplied before conception and during the first month of fetal development, which is when closure of the neural tube occurs. 11 The WHO and Centers for Disease Control and Prevention (CDC) recommend that foods be fortified with 1.4 mg/kg folic acid of the product because folate has been strongly associated with NTDs. 12 In addition to fortified foods and folate obtained from dietary sources, the WHO recommends a folic acid supplementation of 400 μg/d to be taken 3 months before conception and during the first trimester to prevent NTDs, and 5 mg/d if there is a record of any previous history of NTDs. 9, 13
The dietary habit formed during pregnancy globally has again been found to play an important role in birth outcomes. 14 The dietary intake of the pregnant woman should be able to provide the nutrients needed by both mother and fetus. Research shows there is a positive association between a healthier dietary pattern practiced by the expectant mother and the infant’s birthweight. 15 Folate and iron are nutrients of great importance during this period because of the major roles they play in many metabolic processes during pregnancy and in birth outcomes. 16 Dietary iron and folate have been shown to have effects on fetal and neonatal development. It has been proved that if these nutrients are in sufficient amounts in the diet of pregnant women, they result in optimal birthweights, reduced risk factors for prematurity, and reduced occurrence of fetal distress, which contribute to low perinatal morbidity and mortality. 17 Research has again shown that iron needs, for example, increase significantly during the third trimester 18 and, similarly, there is also an increased demand for folate as well for rapid cell proliferation and tissue growth of the uterus and placenta, growth of the fetus, and expression of maternal blood volume. 19
In the 2017 Ghana Micronutrient Survey, it was shown that although anemia prevalence among the selected urban and rural areas in which the study was conducted had reduced over the years, it was still unacceptably high (45% prevalence rate) despite supplementation given to pregnant women. 20 The study therefore recommended the consumption of iron-rich foods in addition to supplementation during pregnancy to combat anemia. This was mainly because iron deficiency appeared to be the main driver of anemia in many cases.
The dietary habits of most pregnant women have been shown to differ among the various trimesters and among the women as they progress to the third trimester. Although many studies of nutrient intake have been conducted on pregnant women, the focus has been on the earlier trimesters. 21, 22 Fewer studies have looked at dietary intake during the third trimester. 23, 24 A study conducted on dietary habits among Black American women in their third trimester is one of few studies that have focused on nutrition during the third trimester. That study showed that food intake by these women declined from the beginning of the third trimester to the end. This was attributed to certain factors such as the feeling of fullness with little consumption, fear of gaining weight, and heartburn, resulting in most of the participants not meeting their RDAs. 24
Anecdotal evidence suggests a similar pattern among pregnant women in Ghana. In one of Ghana’s tertiary hospitals, Korle-Bu Teaching Hospital (KBTH) studies conducted have focused on health conditions such as hypertension and diabetes, and their effects on birth outcomes. 25, 26 What is required is an assessment of maternal dietary intake during the third trimester and pregnancy outcomes.
METHODS
Study design and participants.
Our study used a prospective cohort design for a duration of 8 weeks. Women age 18 to 49 years and in their third trimester (32 weeks) attending antenatal clinics at the Department of Obstetrics and Gynecology, KBTH, were recruited using a consecutive sampling method. Pregnant women who were in their third trimester but had records of obstetric complications, sickle cell disease, and other health conditions such as diabetes and hypertension were excluded from the study. Participants who refused to provide consent were excluded from the study. In total, 81 eligible pregnant women were recruited for the study.
Ethical approval.
Approval for this study was obtained from the Ethics and Protocol Review Committee, College of Health Sciences (protocol identification no. CHS-Et/M3-16/2019-2020). Permission was also obtained from the Department of Obstetrics and Gynecology, KBTH. Written informed consent was obtained from the participants.
Procedure for data collection.
Data were collected in four main parts. Structured questionnaires were adopted from Owusu 27 and modified to suit the study.
Assessment of participants (sociodemographic characteristics).
General information on the study participants was gathered by the primary investigator using a face-to-face interviewer-administered questionnaire. The information included the sociodemographic and economic details, as well as health-related characteristics (such as alcohol consumption, frequency of antenatal care visits, and medication use).
Assessment of nutrient intake.
The dietary intake of the participants was measured with a 52-item quantitative food frequency questionnaire. Participants were asked questions about their usual weekly intake of folate and iron-rich food sources, and their answers were used to obtain both daily and weekly intake of these nutrients. Six food groups (starchy roots and plantains; cereals and grains; animal products; legumes, nuts, and oilseeds; fruits and vegetables; and fats and oils) with a list of their food items were used in this study. Food intake with their amounts or portions were provided by the participants through recall and the amounts recorded in handy measures that were then converted to grams. The converted amounts were analyzed using Microdiet Nutrient Analysis software (version 3) to obtain nutrient intake.
Participants were asked to provide the type or brand, amounts, and frequency of all dietary supplements they were currently taking in the third trimester. Some of the brands included folic acid tablets (5 mg folic acid taken once a day), Pregnacare Original (Vitabiotics; 400 μg folic acid and 17 mg iron taken once a day), Tot’hema (Innotech; 5 mg iron taken once or twice a day), and Vitafol (1,700 μg folic acid and 29 mg iron taken once daily). Daily iron and folic acid supplement consumption was calculated by multiplying the iron and folic acid contents of each reported supplement to the number of tablets taken daily. The total was then multiplied by the frequency of daily consumption. Total daily iron consumption was derived from the sum of dietary iron and oral iron supplements, as was total daily folate intake. The RDA for dietary iron during pregnancy is 27 mg/d and that of dietary folate is 0.6 mg according to the WHO. 13 The recommendations for daily oral iron and folic acid supplementation are 30 to 60 mg and 0.4 mg, respectively. 13
Biochemical assessment.
Participants’ sera levels of iron (ferritin) and folate were assessed at 36 weeks using Accu-Bind Ferritin (or Folate) 96 microwell ELISA plates (Lake Forest, CA). The most recent results of laboratory tests for hemoglobin (within the past month before recruitment) and worm infestation information (if available) were extracted from respondents’ hospital records. To determine iron deficiency based on participants’ ferritin levels, a reference value of < 15 ng/mL was associated with iron deficiency. 28 United Nations University’s 29 standard of measuring folate deficiency was also adopted. A serum folate deficiency value is said to be < 10 nmol/L (4 ng/mL).
Determination of birth outcomes.
After delivery, birth outcome information (birthweight, gestational age, Apgar score at minutes 1 and 5, neonatal and maternal survival) of the participants was taken from their records using an observational checklist (information related to birth outcomes). 30 These findings are summarized using statistics such as mean and standard deviation (SD). Birth outcomes were defined as follows: 1) normal birthweight (birthweight ≥ 2.5 kg), 2) term birth (gestational age between 37 and 42 weeks), and 3) good Apgar scores (≥ 7 points at both minutes 1 and 5. 9, 31
Statistical analysis.
Data were analyzed using Statistical Package for Social Sciences (SPSS) version 25 (SPSS Inc., Chicago, IL). The level of significance was set at P ≤ 0.05, with a 95% CI.
The semi-quantitative food frequency questionnaire was analyzed using Microdiet Nutrient Analysis software (version 3) to help determine the nutrient intake of the participants. Descriptive analyses (mean and SD, frequencies, and percentages) were used to summarize continuous variables (such as daily dietary and supplement intake, and serum ferritin and folate levels) and categorical variables (such as marital status and income range), represented as tables, graphs, and charts. Spearman’s rank correlation test was used to determine the strength of the relationship between serum levels, dietary intake, and birth outcomes.
RESULTS
All study participants were women who were 18 to 49 years old (mean age, 32.2 ± 6.0 years). The majority (82.7%) of the participants were married. A few (7.4%) of the participants did not have any formal education. Participant demographics are presented in Table 1.
Table 1.
Demographics of participants (N = 81)
| Variables | n (%) |
|---|---|
| Marital status | |
| Single | 14 (17.3) |
| Married | 67 (82.7) |
| Educational level | |
| No formal education | 6 (7.4) |
| Junior high school | 30 (37.0) |
| Senior high school | 19 (23.5) |
| Tertiary | 26 (32.1) |
| Occupation (participant) | |
| Professional | 13 (16.0) |
| Trader | 27 (33.3) |
| Vocation | 28 (34.6) |
| Jobless | 13 (16.0) |
| Occupation (spouse) | |
| Professional | 29 (35.8) |
| Trader | 24 (29.6) |
| Vocation | 27 (33.3) |
| Jobless | 1 (1.2) |
| Participants’ monthly income, GH₵ | |
| 100–299 | 25 (36.8) |
| 300–499 | 12 (17.6) |
| 500–1,000 | 14 (20.6) |
| > 1,000 | 17 (25.0) |
| Spouses’ monthly income, GH₵ | |
| 100–299 | 6 (7.5) |
| 300–499 | 10 (12.5) |
| 500–1,000 | 21 (26.3) |
| > 1,000 | 43 (53.8) |
| Total household monthly income, GH₵ | |
| No household income | 1 (1.2) |
| 500–1,000 | 18 (22.2) |
| > 1,000 | 62 (76.5) |
One U.S. dollar = 6.1 Ghana cedis (GH₵).
Status of iron and folate intake.
Table 2 shows the iron and folate status of the participants. Mean dietary iron intake was 13.5 ± 8.30 mg; dietary folate was 331.1 ± 113.4 μg. Mean iron supplement intake was 42.7 ± 48.80 mg; folic acid was 5.50 ± 11.1 mg. Mean total iron intake from diet and supplements was 56.2 ± 50.3 mg; total folate intake from diet and supplements was 5.59 ± 10.9 mg. The proportions of participants who had a total iron and folate intake less than the RDA of 57 to 87 mg and 1 mg for iron and folate, respectively, were 74.1% and 86.4%. The sera levels and the most recent hemoglobin levels of the participants are presented in Table 2. The maximum sera level of iron (ferritin) was 145.2 ng/mL, folate was 33.1 nm/mL, and hemoglobin was 13.4 g/dL.
Table 2.
Summary of participants’ daily iron and folate consumption (diet and supplements) and sera levels (ferritin and folate) with their recommendations (N = 81)
| Value | Daily dietary intake | Daily supplement intake | Total iron and folate intake | Serum ferritin, ng/mL | Serum folate, ng/mL | Hb level, g/dL | |||
|---|---|---|---|---|---|---|---|---|---|
| Iron, mg | Folate, µg | Iron dose, mg | Folic acid dose, mg | Total iron, mg | Total folate, mg | ||||
| Mean ± SD | 13.5 ± 8.3 | 331.2 ± 113.4 | 42.7 ± 48.8 | 5.5 ± 11.1 | 56.2 ± 50.3 | 5.69 ± 10.9 | 67.1 ± 42.5 | 10.0 ± 7.7 | 10.6 ± 1.1 |
| Minimum | 5.5 | 158.5 | 0.1 | 0.01 | 5.9 | 0.27 | –2.7 | 1.5 | 8.2 |
| Maximum | 62.39 | 683.9 | 305.0 | 17.0 | 367.2 | 17.7 | 145.2 | 33.1 | 13.4 |
| Recommended | 27.0 | 600.0 | 30.0– 60.0 | 0.4 | 57.0–87.0 | 1.0 | 15.0 | 4.0 | 11.0 |
Hb = hemoglobin.
Figure 1 shows the serum ferritin and folate levels for the participants. The majority (82.7%) of the participants had normal serum ferritin levels. The same outcome was observed for serum folate; almost all participants (87.7%) were within the normal level. Hence, our study obtained a relatively lower deficiency rate for both iron and folate (17.3% and 12.3%, respectively).
Figure 1.
Serum Ferritin and Folate levels of pregnant women in their third trimester attending antenatal care at KBTH.
Birth outcomes of participants.
The birth outcomes obtained by the participants are shown in Table 3. The mean birthweight was 3.26 ± 0.5 kg. A greater proportion of the participants had positive birth outcomes. Almost all participants had full-term births (92.60%) and delivered normal-weight babies (96.30%), and the babies also recorded good Apgar scores at both minute 1 (74.10%) and minute 5 (95.10%). More than half (61.70%) of the deliveries were via cesarean section, and most of the babies (92.60%) were not admitted to the neonatal intensive care unit for observations.
Table 3.
Birth outcomes of participants (N = 81)
| Variables | n (%) |
|---|---|
| Gestational age, weeks | |
| Preterm | 6 (7.4) |
| Term | 75 (92.6) |
| Mode of delivery | |
| Vaginal | 31 (38.3) |
| Cesarean | 50 (61.7) |
| Birthweight, kg | |
| < 2.5 | 3 (3.7) |
| ≥ 2.5 | 78 (96.3) |
| Apgar at minute 1, pt | |
| < 7 | 21 (25.9) |
| ≥ 7 | 60 (74.1) |
| Apgar at minutes 5, pt | |
| < 7 | 4 (4.9) |
| ≥ 7 | 77 (95.1) |
| Baby taken to NICU | |
| Yes | 6 (7.4) |
| No | 75 (92.6) |
NICU = neonatal intensive care unit.
Relationship between total iron (from diet and supplements) and total folate (from diet and supplements), and birth outcomes.
Table 4 summarizes the relationship between daily total iron and folate intake, and birth outcomes. Daily total folate consumption did not correlate with any of the birth outcomes investigated. However, daily total iron intake correlated positively with the Apgar score at minute 5, with a P value of 0.041 and a correlation coefficient of 0.227, indicating a low positive correlation.
Table 4.
Correlation between daily total iron and folate intake and birth outcomes (N = 81)
| Variables | Total daily iron, rs value (P value) | Total daily folate, rs value (P value) | Serum ferritin, rs value (P value) | Serum folate, rs value (P value) |
|---|---|---|---|---|
| Gestational age | –0.023 (0.836) | 0.208 (0.062) | 0.008 (0.943) | 0.138 (0.219) |
| Birthweight | 0.043 (0.163) | –0.082 (0.468) | –0.093 (0.410) | –0.173 (0.121) |
| Apgar at minute 1 | 0.163 (0.145) | –0.028 (0.802) | 0.003 (0.979) | –0.095 (0.401) |
| Apgar at minute 5 | 0.227 (0.041)* | 0.008 (0.945) | 0.037 (0.745) | –0.009 (0.940) |
rs = Spearman’s ranked correlation test.
Significant at P ≤ 0.05.
Relationship between serum ferritin and folate, and birth outcomes.
There was no relationship between the sera levels of the participants and the birth outcomes obtained in the study. There was no statistically significant difference between any of the serum levels and birth outcomes (Table 4).
DISCUSSION
Eighty-one pregnant women in their third trimester participated in this study (mean age, approximately 32 years), and the majority of them were married. Most of the participants were educated formally, with a greater proportion having a household monthly income greater than 1,000 Ghana cedis. Thus, most of the participants in our study were mature, independent, and stable in life with a good socioeconomic status, which could have influenced their dietary intake and habits. The findings in our study are similar to those of Nana and Zema, 32 who concluded that household socioeconomic (income and employment) status was a major predictor of dietary intake and habits.
The proportion of participants who met the RDAs for iron and folate was low in our study compared to a study conducted among French-Canadian pregnant women. 33 However, our study had a similar outcome compared with other previous studies carried out to determine total daily iron and folate intake among pregnant women in their third trimester. 12, 34 A possible reason for the outcome obtained in our study could be that participants consumed an inadequate amount of food. The inadequate intake could be related to complaints by some of the participants on the difficulties they were experiencing with food intake, including heartburn after eating, a feeling of discomfort after meals, and early satiety with little consumption. The findings in our study are also comparable to those of another, in which the participants in their third trimester attributed inadequate food consumption to similar reasons; hence, the majority could not meet their total RDAs for micronutrients. 24 Nonetheless, pregnant women—and especially those in their third trimester—should be encouraged to meet dietary recommendations, because their nutritional needs increase during this time and insufficient nutrient intake could lead to adverse birth outcomes. 35
Serum levels of participants were obtained from both diet and supplements. Although the RDAs for total daily dietary iron and folate intake in our study were not met, most of the participants recorded normal levels for serum ferritin and folate. The serum levels obtained are similar to those of another, in which the majority (88.8%) of the participants had normal serum ferritin levels. 36 However, conversely to our study, in which the prevalence rate for iron (17.3%) and folate (12.3%) deficiencies were low, the 2017 Ghana Micronutrient Survey recorded a greater prevalence rate (45%) among the pregnant women studied. 20 The majority of the participants recording normal serum levels despite a lower dietary intake in our study could also be attributed to better absorption rates of supplements through the absorption pathway than diet, 7 considering the fact that almost all the participants met the daily recommendations for supplementation. In addition, participants who fell within the maximum consumption category for the supplements exceeded the upper limit for both nutrients (iron and folic acid maximum doses consumed by the participants were 305 mg and 17 mg, respectively, which is far above the daily recommended values of 30–60 mg and 0.4 mg, respectively), which could play a role in normalizing serum levels. Regardless, efforts should be made to ensure pregnant women meet both diet and supplement needs, and not over-depend on supplementation to obtain normal serum levels. Adequate diet confers multiple benefits compared with the intake of a supplement that contains a particular nutrient. Evidence also supports the optimal intake of nutrients from both diet and supplements as necessary to achieve optimal birth outcomes. 20
The majority of the participants in our study obtained positive birth outcomes, including no records of stillbirths, most of them delivering at 39 weeks, almost all babies obtaining normal weight, and the majority obtaining Apgar scores greater than 7 points at minutes 1 and 5. The findings in our study are similar to those of Nicholson et al., who found that the optimal gestational age to minimize obstetrics complications was between 39 to 40 weeks. 31 According to the WHO, 37 the optimal birth weight for children is ≥ 2.5kg, with an Apgar score of 7 points at minutes 1 and 5 after delivery. Activity, pulse, grimace (reflex irritability), appearance (skin color), and respiration are evaluated 1 and 5 minutes after birth to determine the health of the neonate. 37 As a result of the positive birth outcomes obtained by the participants, almost all the neonates in our study were not admitted at the neonatal intensive care unit after delivery. This outcome could be related to the normal sera levels (ferritin and folate) obtained by the majority of mothers. Our findings reiterate the importance of positive birth outcomes, including the possibility of reducing the occurrence of lifelong consequences as a result of adverse birth outcomes, ensuring quality of life, and reducing health-care costs. 6 Expectant mothers need to be encouraged by educating them to prioritize and meet their nutritional needs to obtain a positive birth outcome.
Our study had no statistically significant correlation between total folate and birth outcomes, but obtained a significant weak positive correlation between total iron intake and Apgar score at minute 5 (r = 0.227, P = 0.041). These results are similar to the findings of Nilsen et al., 31 who found no correlation between total folate consumption and birth outcomes. Contrary to the results of our study regarding the relationship between total iron intake and birth outcomes, a cross-sectional study conducted in northwestern China found no correlation between total iron intake and birth outcomes in pregnant women in their third trimester. 31
Regarding sera levels, no significant correlation was obtained between ferritin or folate levels and birth outcomes, which is similar to the results reported by Kalem et al., 37 which also showed no correlation between the serum levels of ferritin and folate in the participants and birth outcomes (mode of delivery and birthweight) investigated. Thus, intake of folate (from diet and supplements) by the participants in our study and their sera levels (ferritin and folate) did not affect the birth outcomes obtained. The only significant predictor of birth outcomes in our study was total iron intake (from diet and supplements). This implies that, because daily iron recommendations were met by the participants, it resulted in a greater Apgar score at minute 5, with improved breathing, heart rate, muscle and skin tone, and reflexes of the neonates. 9 Expectant women, especially in their third trimester, should therefore be encouraged through nutritional education and counseling to meet both diet and supplement recommendations to sustain the normal growth of the fetus and achieve optimum birth outcomes. 38
The limitations of this study include the fact that C-reactive protein and other inflammatory markers that affect serum ferritin levels were not measured. Also, the short study period may not reflect seasonal differences in dietary intake. Last, there was no analysis of the association between iron intake and serum ferritin.
CONCLUSION
Our study showed that a greater percentage of the participants did not meet the daily dietary recommendations for both nutrients (iron and folate), which could be attributed to the suboptimal amount of food consumed by the majority of them. Nonetheless, adherence to the daily supplement intake was generally good among the participants, and this could have contributed to the normal serum ferritin and folate levels noted as well as the positive birth outcomes observed.
ACKNOWLEDGMENTS
We are grateful to all the pregnant women who took part in our study for their corporation and immense contribution. The American Society of Tropical Medicine and Hygiene (ASTMH) assisted with publication expenses.
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