INTRODUCTION
The issues related to the diets of pregnant women remain relevant and extremely important for the health status of future generations. The appropriate diet of a woman during pregnancy has an impact on her nutritional status, course of pregnancy and the health of the child — in utero, childhood, and in adulthood. According to the theory of metabolic programming, unfavourable environmental conditions, including nutritional conditions, related to the deficiency or excess of nutrients during the fetal life may cause changes in the structure, metabolism and functioning of the body, thus increasing the risk of developing diet-related diseases in adulthood [1–3]. The nutritional status of a pregnant woman is one of the main factors ensuring the maintenance of pregnancy, its appropriate course and minimizing the risk of complications in the fetus. Maternal undernutrition may contribute to the reduction of the weight of the placenta, thus causing its dysfunction, intrauterine growth restriction, low birth weight of infant and premature delivery, whereas overweight and obesity in the mother may be conducive to hypertension, gestational diabetes, urinary tract infections, fetal macrosomia and surgical delivery. Therefore, it is important to monitor the weight gain during pregnancy with reference to the body mass index before pregnancy [4–7].
During pregnancy, the need for energy, essential nutrients, vitamins and minerals changes. Therefore, the balance between increased nutritional needs and the nutritional value of the diet should be achieved by the appropriate selection of products, the introduction of fortified foods and/or appropriate dietary supplementation [8].
In recent years, in nutritional assessment, an increasing attention has been paid to dietary patterns of various population groups as a comprehensive method for determining the relationship between the diet and the nutritional status. The analysis of dietary patterns is considered a holistic, alternative and complementary approach to assessing the dependencies between the diet and the risk of chronic disease by evaluating the impact of the overall diet and its complexity. Dietary patterns are defined as a set of numerous specific, co-existing characteristics describing the human diet. These characteristics may define the type and amount of nutrients, foodstuffs or groups of products, the frequency of eating meals, food preferences or avoidance of certain foods [9, 10]. Optimal eating patterns, which represent the set of nutritional characteristics that are the most beneficial for health, are referred to as “dietary patterns” [11].
Objectives
The aim of the study was to assess, through identified dietary patterns, the diets of women in the second and third trimester of pregnancy in relation to their nutritional status before and during pregnancy.
MATERIAL AND METHODS
Study group
The study was conducted in the years 2012–2018 among participants of childbirth classes conducted at the Institute of Mother and Child in Warsaw. The courses took place four times a year during this period, in which 796 pregnant women attended the childbirth classes. All women were invited to participate in the study. Out of 796 pregnant women, 448 (56%) decided to participate in the study and completed the questionnaire. The main reason for not completing the questionnaire was the lack of interest to participating in the study and the failure to meet the criteria (44%) of inclusion and exclusion from the study group. The study involved women who agreed to complete an anonymous questionnaire. A total of 448 questionnaires were collected, of which 392 were included in the study, only those that were completed without missing data (Tab. 1). The inclusion criteria were: first and single pregnancy without complications, maternal age 19–40 years, and attending a childbirth education classes at the Institute of Mother and Child in Warsaw.
|
Table 1. The number of course participants and collected questionnaires |
|||
|
Year of the study |
Number of courses* |
Number of participants in 4 courses |
Number of collected questionnaires |
|
2012 |
4 |
112 |
76 |
|
2013 |
4 |
116 |
70 |
|
2014 |
4 |
112 |
60 |
|
2015 |
4 |
120 |
54 |
|
2016 |
4 |
112 |
51 |
|
2017 |
4 |
120 |
75 |
|
2018 |
4 |
104 |
62 |
|
7 years |
28 |
796 (100%) |
448 (56%) |
|
*A maximum of 30 women could participate in one course due to practical classes and exercises |
|||
Analysis of the nutritional status
The nutritional status of pregnant women was examined based on body weight [kg], height [m] and body mass index BMI [kg/m2] before and during pregnancy. Data were obtained from the questionnaire entries and current measurements. The recommendations of the American Institute of Medicine, which constitute the current medical standard, were used to assess the nutritional status of women before and during pregnancy [12].
Diet analysis
The diet was analysed using the data from the food frequency questionnaire (FFQ), which included the usual portion size, and the 24-hour dietary records (recall and record method) [13]. The diet record was used to verify the usual portion sizes of products using the product and food photography album [14]. The dietary patterns of pregnant women were identified using the k-means method based on product groups from the food frequency questionnaire. In accordance with adopted statistical procedure for identifying dietary patterns, an analysis was made of the grouping of products used in the diets of pregnant women at several levels of categorization in line with the grouping adopted in the Diet 6 dietary computer program. Then, the dimensions of the analysis were reduced using the factor analysis method, which allowed to reflect the acceptable level of overall variability. K-means clustering method was used to identify dietary patterns. Both the grouping parameters and the number of dietary patterns were analyzed in terms of quantitative parameters (group size) and qualitative parameters (interpretation possibilities). The standard is to identify 2–4 dietary patterns. The energy and nutritional value profile in the identified dietary patterns was also analysed using the Diet 6 nutritional computer programme [15]. The obtained results were compared with the current nutrition standards and medical standards [16–18].
Statistical analysis
The statistical analysis of the obtained results was performed using the IBM SPSS 21 statistical program. The median and quartile ranges were used to describe quantitative variables due to the lack of conformity of the distributions of variables with the normal distribution. P < 0.05 was adopted as the level of statistical significance. To assess the relationship between the diet and the nutritional status of pregnant women, Student’s t-tests and analysis of variance were used for quantitative variables fulfilling the conditions of normal distribution and homogeneity of variance. Non-parametric Mann-Whitney and Kruskal-Wallis tests were used for quantitative variables that did not meet the conditions of normal distribution and homogeneity of variance. The Chi-square test of independence was used to analyse the body mass index (BMI) and weight gain as categorical variables. The principal component analysis with Quatrimax rotation, including Bartlett sphericity tests, and k-means cluster analysis were used to identify the dietary patterns of the studied women. The energy value and the share of individual components in the average daily food ration of the studied women were expressed in the form of the mean and standard deviation as well as the median and quartiles 1 and 3. The percentage of women whose nutrient intake was below the average requirement of the group (EAR) and above the adequate intake (AI) was also calculated.
RESULTS
Characteristics of the study group
The study involved 392 women. Table 2 presents the characteristics of the studied group. The vast majority of the respondents had completed higher education and were residents of large cities. Most of the women were in the third trimester of pregnancy.
|
Table 2. Characteristics of the studied group |
|
|
Variables |
Pregnant women (n = 392) n (%) |
|
Women’s age [years]
|
1 (0.3) 205 (52.3) 186 (47.4) |
|
Place of residence
|
366 (93.4) 18 (4.6) 8 (2.0) |
|
Education
|
1 (0.3) 46 (11.7) 345 (88.0) |
|
Trimester of pregnancy
|
137 (35.0) 255 (65.0) |
Assessment of the nutritional status of the studied women
Table 3 presents the nutritional status of the studied women, determined using prepregnancy BMI. The appropriate BMI values before pregnancy were recorded in 76.3% of the examined women. Based on the data on the current body weight and the body weight before pregnancy, the mean weight gain of the studied pregnant women was calculated with reference to the prepregnancy BMI (Tab. 4).
|
Table 3. Prepregnancy BMI of the studied women |
|
|
Variables |
Studied group of women (n = 392) n (%) |
|
Prepregnancy BMI [kg/m2]
|
43 (10.9) 299 (76.3) 40 (10.2) 10 (2.6) |
|
BMI — body max index |
|
|
Table 4. Average weight gain of the studied women depending on prepregnancy BMI |
|||||||
|
Prepregnancy BMI [kg/m2] |
Average weight gain in pregnancy [kg/week] |
Recommended weight gain according to Institute of Medicine (2009) |
p |
||||
|
x |
SD |
Me |
1Q–3Q |
Min–max |
|||
|
Body weight deficiency: BMI ≤ 18.5 |
0.56 |
0.17 |
0.55 |
0.44–0.68 |
0.27–1.00 |
0.51 |
0.000 |
|
Normal body weight: BMI 18.5–24.9 |
0.55 |
0.20 |
0.53 |
0.43–0.65 |
–0.05–1.27 |
0.42 |
|
|
Excess body weight: BMI ≥ 25.0 |
0.40 |
0.25 |
0.43 |
0.25–0.56 |
–0.21–1.08 |
0.22–0.28 |
|
|
BMI — body max index; x — mean; SD — standard deviation; Me — median; 1Q–3Q — 1 quartile–3 quartile; min–max — range minimum–maximum; Kruskal-Wallis p < 0.005 |
|||||||
The mean weight gain during pregnancy was higher than recommended in all three subgroup. The highest mean gains were observed in the group of women with body weight deficiency before pregnancy (0.56 vs 0.51 kg/week), and the lowest in the group of women with excess body weight (0.40 vs 0.22–0.28 kg/week). In the group of women with appropriate body weight before pregnancy, the mean weight gain during pregnancy was 0.55 kg/week (norm 0.42 kg/week). There were statistically significant differences between the groups in the mean weight gain of pregnant women in relation to their prepregnancy BMI (p < 0.05).
Assessment of the diets
As a result of the cluster analysis, three dietary patterns of the studied pregnant women were identified. Figure 1 shows the distribution of the mean values for each cluster (dietary pattern).
The identified patterns were defined as follows:
- Dietary pattern 1 — with predominance of cereal products and butter, rennet cheeses and fermented milk drinks, defined as the cereal-milk diet.
- Dietary pattern 1 was characterised by high consumption of such products as cereals and butter, rennet cheeses and fermented milk drinks, as well as meat, poultry, cold cuts, and sugar. Dietary pattern 1 was characterized by low consumption of vegetables, including potatoes and fruit. Dietary pattern 1 was adhered to by 33.4% (n = 131) of the studied women.
- Dietary pattern 2 — with a definite predominance of vegetables, fruit and potatoes, was defined as the vegetable-fruit diet. Dietary pattern 2 was characterized by high consumption of vegetables, including potatoes and fruit. The consumption of cereal products and butter, meat, poultry and cold cuts exceeded the average consumption for the whole group, but less than the products from the vegetables group, including potatoes and fruit. Milk consumption was also slightly above the average. This pattern also involved low consumption of cottage cheese and rennet cheeses, fermented milk drinks and sugar. Dietary pattern 2 was adhered to by 21.7% (n = 85) of the studied women.
- Dietary pattern 3 — with predominance of cottage cheese, as well as a higher than average consumption of fish and cooked vegetables was defined as the cottage cheese-vegetable diet. Dietary pattern 3 was characterized by high consumption of cottage cheese. The majority of the analysed product groups did not differ significantly from the average for the entire group, but the consumption of fish and cooked vegetable dishes as well as the consumption of milk deserve attention. However, in the consumption structure of the identified patterns, the consumption of fish did not differ significantly, therefore dietary pattern 3 was named the cottage cheese-vegetable diet. This pattern also involved significantly lower consumption of cereal products and butter as well as meat, poultry and cold cuts. Dietary pattern 3 was adhered to by 44.9% (n = 176) of the studied women. Table 5 presents the characteristics of the identified dietary patterns based on the product consumption structure.
Table 5. Characteristics of the identified dietary patterns based on the product consumption structure | ||||
Group of products [g] | Dietary pattern 1(A) cereal-milk diet | Dietary pattern 2(B) vegetable-fruit diet | Dietary pattern 3(C) cottage cheese-vegetable diet | p** |
x ± SD*** (Me, Q1–Q3)* | ||||
Cereals (in terms of flour) | 192.1 ± 64.1B, C (192.4, 146.2–223.9) | 166.2 ± 70.7A, C (148.0, 119.0–201.7) | 117.9 ± 52.2A, B (117.5, 79.7–148.0) | 0.000 |
Milk | 145.1 ± 114.5 (140.0, 70.0–250.0) | 161.3 ± 136.5 (140.0, 70.0–250.0) | 160.6 ± 145.4 (140.0, 70.0–250.0) | 0.736 |
Fermented milk drinks | 185.0 ± 144.0 (143.0, 85.0–250.0) | 183.5 ± 147.2 (150.0, 85.0–280.0) | 189.3 ± 143.9 (152.5, 85.0–280.0) | 0.910 |
Cottage-cheese (in terms of milk) | 352.5 ± 278.7B (335.0, 201.0–402.0) | 243.8 ± 183.9A, C (201.0, 113.9–402.0) | 360.3 ± 327.2B (288.1, 154.1–452.3) | 0.011 |
Rennet cheese | 45.6 ± 25.7B, C (40.0, 34.0–60.0) | 21.5 ± 19.0A (17.0, 6.0–35.0) | 16.3 ± 11.3A (11.0, 11.0–23.0) | 0.000 |
Meat and poultry | 219.6 ± 100.0C (206.0, 158.0–273.0) | 218.8 ± 91.6C (218.0, 171.0–285.0) | 156.6 ± 78.9A, B (158.0, 103.0–206.0) | 0.000 |
Cold cuts | 55.0 ± 32.1 48.6, (28.0–80.4) | 38.2 ± 31.9 (39.1, 10.3–51.5) | 24.9 ± 21.8 (20.7, 6.5–42.6) | 0.000 |
Fish and seafood | 47.9 ± 37.6 (60.0, 0.0–60.0) | 46.9±36.0 (60.0, 0.0–60.0) | 48.7 ± 37.2 (60.0, 0.0–60.0) | 0.891 |
Butter and cream | 20.8 ± 9.9B, C (20.0, 15.0–25.0) | 16.3 ± 10.4A, C (15.0, 10.0–20.0) | 10.4 ± 8.2A, B (10.0, 3.0–16.0) | 0.000 |
Vegetables and fruits | 659.2 ± 263.9B, C (599.8, 475.9–808.4) | 1030.4 ± 420.8A, C (989.7, 671.3–1355.7) | 795.2 ± 353.6A, B (775.3, 556.1–947.6) | 0.000 |
Cooked vegetables | 60.9 ± 69.9C (43.0, 0.0–100.0) | 90.4 ± 90.7 (80.0, 0.0–150.0) | 83.2 ± 85.8A (60.0, 10.0–128.0) | 0.025 |
Cooked potatoes | 92.4 ± 56.1B, C (85.0, 60.0–115.0) | 198.4 ± 69.2A, C (170.0, 150.0–250.0) | 64.6 ± 45.3A, B (60.0, 43.0–85.0) | 0.000 |
Sugar | 16.4 ± 13.2B, C (11.0, 6.0–23.0) | 11.9 ± 10.9A (11.0, 6.0–17.0) | 12.3 ±١٠.٣A (11.0, 6.0–17.0) | 0.006 |
* x ± SD (Me, Q1–Q3) — mean ± standard deviation (median; 1 quartile–3 quartile) ** statistically significant differences in the consumption of groups of products between the three clusters of the studied women (Kruskal-Wallis; p < 0.005) *** statistically significant differences between clusters of studied women A, B, C calculated using a post hoc test (multiple two-sided comparisons) | ||||
Figure 2 shows the frequency of the identified dietary patterns in the subgroups of pregnant women in relation to their nutritional status determined using the BMI before pregnancy. The most frequent dietary pattern in all groups of women was pattern 3, defined as the cottage cheese-vegetable diet. There was no statistically significant relationship between the dietary patterns and prepregnancy body mass index (BMI). The frequency of dietary patterns depending on weight gain during pregnancy and BMI before pregnancy was also analysed (Fig. 3).
Assessment of the frequency of dietary patterns depending on the weight gain in pregnancy and the BMI before pregnancy showed that dietary pattern 1 (cereal-milk diet) occurred most often in the group of women with excess body weight before pregnancy whose weight gain during pregnancy was above than recommended (75.0%). Dietary patterns 1 and 2 occurred most often in the group of women with underweight before pregnancy whose weight gain during pregnancy was in the line with the recommendations and above (40.0% and 53.8% respectively). In the group of women with appropriate body weight before pregnancy, a more even distribution of the identified patterns was observed.
Assessment of the nutrient profile in the identified dietary patterns
Table 6 shows the energy value and nutrient profile of three identified dietary patterns in pregnant women.
|
Table 6. Comparison of energy value and nutrient profile of the three dietary patterns with the nutritional recommendations |
|||||||||||
|
Energy and nutrients |
Dietary pattern 1 (A) cereal-milk diet |
Dietary pattern 2 (B) vegetable-fruit diet |
Dietary pattern 3 (C) cottage cheese-vegetable diet |
p |
NIZP-PZH (2020) [16], EFSA 2017 [17] EAR/AI |
||||||
|
x ± SD** |
Me |
1Q–3Q |
x ± SD** |
Me |
1Q–3Q |
x ± SD** |
Me |
1Q–3Q |
|||
|
Basic nutrients |
|||||||||||
|
Energy [kJ] |
10645.7 ± 1982.4C |
10423.5 |
9437.8–11560.9 |
10716.8 ± 2074.3C |
10271.0 |
9240.0–12138.4 |
8581.8 ± 1810.4A, B |
8637.9 |
7426.5–9971.0 |
0.000 |
– |
|
Energy [kcal] |
2531.8 ± 470.9C |
2487.3 |
2243.1–2743.9 |
2547.3 ± 493.1C |
2446.5 |
2197.5–2882.9 |
2040.3 ± 430.6A, B |
2055.2 |
1766.8–2371.2 |
0.000 |
2200+85 (I trymestr) 2200+285 (II trymestr) 2200+475 (III trymestr) |
|
Total protein [g] |
135.2 ± 29.6C |
130.9 |
115.5–151.4 |
128.1 ± 28.9C |
128.6 |
111.5-144.9 |
104.4 ± 26.7A, B |
101.8 |
83.8–126.6 |
0.000 |
44–78 |
|
Animal protein [g] |
102.5 ± 27.1C |
97.8 |
85.1–114.6 |
91.,4 ± 25.9C |
90.5 |
78.1–106.7 |
76.8 ± 25.2A, B |
74.7 |
58.4–94.1 |
0.000 |
– |
|
Plant-based protein [g] |
32.3 ± 8.1B,C |
31.0 |
25.8–37.0 |
36.1 ± 10.3A, C |
34.6 |
30.0–40.8 |
26.9 ±٧.٣A, B |
26.8 |
21.9–31.5 |
0.000 |
– |
|
Fat [g] |
84.2 ± 18.0B,C |
81.9 |
71.0–96.8 |
75.8 ± 18.5A, C |
75.0 |
62.5–88.6 |
64.0 ± 17.7A, B |
63.4 |
51.9–76.2 |
0.000 |
+3 (I trimester) +10–11 (II trimester)* +16–19 (III trimester) |
|
Cholesterol [mg] |
380.0 ± 103.1C |
371.2 |
304.9–449.8 |
349.5 ± 117.0C |
348.7 |
258.6–400.1 |
287.7 ± 97.2A, B |
266.8 |
221.0–348.8 |
0.000 |
– |
|
Saturated faty acids [g] |
33.3±7.5 |
32.4 |
28.4–37.8 |
26.9 ± 8.1C |
27.3 |
22.1–32.0 |
22.2 ± 6.8 B |
22.0 |
16.9–27.2 |
0.000 |
As low as achievable in a diet that provides adequate nutritional value |
|
Monounsaturated fatty acids [g] |
31.8 ± 8.2C |
30.6 |
25.8–37.2 |
29.3 ± 8.9C |
28.7 |
23.7–34.1 |
24.8 ± 8.1A, B |
24.3 |
19.2–29.1 |
0.000 |
– |
|
Polyunsaturated fatty acids [g] |
13.1 ± 4.5 |
12.4 |
10.0–15.5 |
13.8 ± 4.6 |
13.8 |
10.8–16.8 |
12.4 ± 5.4 |
11.3 |
8.7–15.8 |
0.110 |
Linoleic acid 4% en. α-linolenic acid ٠,٥٪ |
|
Linoleic acid [g] |
9.6 ± 3.3C |
8.9 |
7.2–11.1 |
10.0 ± 3.3C |
9.6 |
7.8–12.0 |
8.7 ± 4.1A, B |
7.8 |
5.8–11.1 |
0.001 |
4% of energy |
|
α-linolenic acid [g] |
2.3 ± 0.9 |
2.1 |
1.7–2.7 |
2.4 ± 0.9 |
2.4 |
1.7–3.0 |
2.3 ± 1.4 |
2.0 |
1.4–2.8 |
0.101 |
α–linolenic acid 0,5% |
|
Long chain polyunsaturated fatty acids [g] |
1.0 ± 1.1 |
0.3 |
0.1–2.0 |
1.1 ± 1.2 |
0.3 |
0.1–2.1 |
1.2 ± 1.3 |
0.3 |
0.1–2.0 |
0.908 |
DHA+EPA 250+100–200 mg DHA |
|
Omega 3 fatty acids [g] |
3.4 ± 1.7 |
3.0 |
2.1–4.4 |
3.6 ± 1.8 |
3.4 |
2.1–4.7 |
3.5 ± 2.1 |
3.4 |
1.8–4.5 |
0.708 |
– |
|
Omega 6 fatty acids [g] |
9.8 ± 3.4C |
9.1 |
7.3–11.4 |
10.2 ± 3.3C |
9.8 |
8.0–12.3 |
8.9 ± 4.1A, B |
7.9 |
6.0–11.4 |
0.001 |
Linoleic acid 4% of energy |
|
Docosaheksaenoic acid (DHA) [g] |
0.7 ± 0.7 |
0.2 |
0.1–1.3 |
0.7 ± 0.8 |
0.2 |
0.1–1.3 |
0.8 ± 0.8 |
0.2 |
0.1–1.3 |
0.913 |
100–200 mg |
|
Eicosapentaenoic acid (EPA) [g] |
0.2 ± 0.2 |
0.1 |
0.0–0.4 |
0.3 ± 0.3 |
0.1 |
0.0–0.4 |
0.3 ± 0.3 |
0.1 |
0.0–0.4 |
0.801 |
250 mg |
|
Carbohydrates [g] |
323.3 ± 75.5B, C |
313.6 |
273.5–360.5 |
355.5 ± 82.7A, C |
344.0 |
302.9–401.0 |
275.5 ± 68.9A, B |
265.8 |
228.7–330.1 |
0.000 |
– |
|
Saccharose [g] |
57.6 ± 26.2 |
52.6 |
40.7–71.2 |
63.1 ± 28.3C |
57.6 |
43.9–76.2 |
53.9 ± 25.2 B |
50.9 |
34.7–67.3 |
0.030 |
– |
|
Glucose [g] |
16.9 ± 7.7 B |
15.7 |
11.7–20.2 |
24.8 ± 11.2A, C |
23.0 |
17.0–33.3 |
18.2 ± 7.6 B |
17.0 |
13.0–22.8 |
0.000 |
– |
|
Fructose [g] |
22.8 ± 10.12 B |
20.7 |
15.7–27.4 |
31.4 ±١٣.٠A, C |
31.2 |
21.6–40.6 |
23.8 ± 10.2 B |
21.7 |
17.3–28.1 |
0.000 |
– |
|
Starch [g] |
155.9 ± 45.7C |
148.7 |
124.0–181.5 |
156.5 ± 53.5C |
156.5 |
123.5–179.1 |
111.0 ± 37.3A, B |
110.6 |
82.8–137.6 |
0.000 |
– |
|
Fibre [g] |
29.8 ± 8.9 B |
28.7 |
22.6–36.5 |
34.2 ± 10.9A, C |
33.0 |
25.5–42.2 |
27.1 ± 8.6 B |
26.3 |
20.8–32.3 |
0,000 |
– Level to be agreed with doctor or dietitian |
|
Minerals |
|||||||||||
|
Sodium [mg] |
3383.1 ± 719.0C |
3244.5 |
2876.3–3899.7 |
3231.0 ± 846.3C |
3158.8 |
2647.1–3787.0 |
2358.6 ± 615.3A, B |
2332.4 |
1950.7–2643.2 |
0.000 |
1500 (AI) |
|
Potassium [mg] |
4743.9 ± 1058.2B,C |
4492.2 |
4023.5–5424.8 |
5799.2 ± 1307.6A, C |
5608.7 |
4901.9–6579.0 |
4400.4 ± 1068.5A, B |
4310.6 |
3673.8–5120.8 |
0.000 |
3500 (AI) |
|
Calcium [mg] |
1290.5 ± 424.5B, C |
1278.2 |
999.2–1515.5 |
1156.7 ± 387.1A |
1174.8 |
923.0–1337.9 |
1091.2 ± 336.7A |
1098.3 |
836.5–1288.1 |
0.000 |
800 |
|
Phosphorus [mg] |
2115.2 ± 465.7C |
2035.5 |
1822.2–2405.1 |
2042.1 ± 437.0C |
2090.7 |
1780.7–2239.4 |
1723.9 ± 446.5A, B |
1654.5 |
1408.7–2036.0 |
0.000 |
580 |
|
Magnesium [mg] |
462.0 ± 102.4B, C |
454.7 |
388.5–521.0 |
510.3 ± 108.5A, C |
500.7 |
430.6–554.9 |
410.2 ± 95.0A, B |
406.1 |
341.1–479.3 |
0.000 |
300 |
|
Iron [mg] |
14.8 ± 3.5C |
14.7 |
12.2–16.8 |
16.1 ± 4.1C |
15.8 |
13.5–18.4 |
12.7±3.2A, B |
12.6 |
10.3–14.4 |
0.000 |
23 |
|
Zinc [mg] |
16.0 ± 3.5C |
15.8 |
13.4–18.5 |
14.9 ± 3.3C |
14.8 |
12.4–16.8 |
12.7 ± 3.1A, B |
12.0 |
9.9–14.2 |
0.000 |
9.5 |
|
Copper [mg] |
1.5 ± 0.4B,C |
1.5 |
1.3–1.8 |
1.8 ± 0.5A, C |
1.8 |
1.5–2.2 |
1.4 ± 0.4A, B |
1.4 |
1.1–1.6 |
0.000 |
0.8 |
|
Manganese [mg] |
7.4 ± 2.6C |
7.4 |
5.4–8.9 |
7.1 ± 2.4C |
7.1 |
5.3–8.4 |
6.2 ± 2.4A, B |
5.9 |
4.5–7.7 |
0.000 |
2.0 (AI) |
|
Iodine [µg] |
127.6 ± 42.9B, C |
122.8 |
99.9–152.9 |
147.3 ± 43.5A, C |
140.3 |
119.7–170.0 |
113.7±39.1A, B |
111.1 |
82.2–140.0 |
0.000 |
160 |
|
Fat soluble vitamins |
|||||||||||
|
Vitamin A (retinol equvalent) [µg] |
1344.9 ± 729.8 |
1191.0 |
819.5–1660.1 |
1424,4 ± 831,1 |
1207,1 |
834.3–1758.3 |
1206.6 ± 665.2 |
1085.1 |
707.0–1574.5 |
0.88 |
530 |
|
Retinol [µg] |
493.0 ± 219.0B, C |
454.0 |
374.0–547.5 |
395.6 ± 207.3A, C |
373.9 |
283.4–459.8 |
336.9 ± 151.1A, B |
313.1 |
235.7–398.0 |
0.000 |
– |
|
Β–carotene [µg] |
5112.5 ± 4303.2 |
4143.7 |
2010.8–7018.9 |
6157.9 ± 4693.7 |
4840.7 |
2651.9–7965.8 |
5216.8 ± 3819.1 |
4298.3 |
2334.1–7207.1 |
0.213 |
– |
|
Vitaminum E [mg] |
13.0 ± 4.2 B |
12.5 |
10.0–15.1 |
15.? ± 5.4A, C |
14.5 |
11.6–18.1 |
12.6 ± 4.4 B |
12.2 |
9.5–14.9 |
0.000 |
10 |
|
Vitaminum D [µg] |
5.7 ± 4.6 |
3.1 |
1.8–9.5 |
5.8 ± 4.8 |
3.0 |
1.7–9.2 |
5.9 ± 5.2 |
3.5 |
1.5–9.0 |
0.377 |
15 |
|
Water soluble vitamins |
|||||||||||
|
Vitaminum B1 [mg] |
2.0 ± 0.4C |
1.9 |
1.7–2.2 |
2.1 ± 0.6C |
2.0 |
1.8–2.4 |
1.6 ± 0.4A, B |
1.6 |
1.3–1.8 |
0.000 |
1.2 |
|
Vitaminum B2 [mg] |
2.5 ± 0.6C |
2.4 |
2.1–2.9 |
2.5 ± 0.6C |
2.5 |
2.1–2.8 |
2.2 ± 0.6A, B |
2.1 |
1.7–2.7 |
0.000 |
1.2 |
|
Vitaminum PP [mg] |
31.1 ± 9.8C |
29.5 |
24.7–35.2 |
33.1 ± 9.7C |
32.8 |
26.9–38.9 |
24.1 ± 7.3A, B |
23.8 |
19.6–28.3 |
0.000 |
14 |
|
Vitaminum B6 [mg] |
3.2±0.8B,C |
3.1 |
2.7–3.7 |
3.8 ± 1.0A, C |
3.8 |
3.2–4.4 |
2.9 ± 0.8A, B |
2.8 |
2.3–3.3 |
0.000 |
1.6 |
|
Folates [µg] |
398.1 ± 103.5 B |
398.4 |
321.8–458.4 |
477.7 ± 149.3A, C |
452.3 |
351.2–575.6 |
387.4 ± 109.9 B |
376.9 |
314.2–457.7 |
0.000 |
520 |
|
Vitaminum B12 [µg] |
6.7 ± 2.5C |
6.4 |
4.8–8.1 |
6.4 ± 2.8 |
5.8 |
4.5–7.7 |
6.0 ± 2.6A |
5.7 |
4.0–7.6 |
0.028 |
2.2 |
|
Percentage of energy from basic nutrients |
|||||||||||
|
Energy from protein [%] |
21.7 ± 3.3 B |
21.3 |
19.5–23.6 |
20.4 ± 3.4A |
21.3 |
19.5–23.6 |
20.8 ± 3.8 |
20.7 |
18.4–23.1 |
0.036 |
10–20 |
|
Energy from fat [%] |
29.7 ± 4.2B, C |
29.3 |
27.1–31.5 |
26.5 ± 4.5A |
29.3 |
27.1–31.5 |
27.9 ± 5.1A |
27.9 |
24.4–31.3 |
0.000 |
20–35 |
|
Energy from carbohydrates [%] |
46.4 ± 5.1B, C |
46.5 |
43.2–49.8 |
50.5 ± 5.8A |
46.5 |
43.2–49.8 |
48.8 ± 6.2A |
48.6 |
44.8–53.0 |
0.000 |
45–65 |
|
Other |
|||||||||||
|
Caffeine [mg] |
133.9 ± 82.4 |
110.0 |
91.5–170.0 |
123.1 ± 79.8 |
110.0 |
91.5–170.0 |
121.8 ± 81.0 |
110.0 |
60.0–170.0 |
0.418 |
< 300 |
|
x ± SD — mean ± standard deviation; Me — median; 1Q–3Q – 1 quartile – 3 quartile p — statistically significant differences in energy and nutrients intakes between dietary patterns (Kruskal–Wallis p < 0.05) EAR — Estimated Average Requirement; AI — Adequate Intake *for women weighing 65 kg, ≥ 30 years fat requirement is assumed 49–86 g, at the level of physical activity PAL = 1.6 [nutritional standards for Poland] [16] ** statistically significant differences between clusters of studied women A, B, C calculated using a post hoc test (multiple two–sided comparisons) |
|||||||||||
The cereal-milk diet (dietary pattern 1) had the highest energy value (Me = 2487.3 kcal). The energy value of the vegetable-fruit diet (dietary pattern 2) was similar (Me = 2446.5 kcal). The cottage cheese-vegetable diet had the lowest energy value (Me = 2055.2 kcal). In the case of the first two dietary patterns, these values were close to nutritional norms, while in the third pattern they were significantly lower. The impact of pregnancy on energy expenditure varies by trimester of pregnancy and varies among women, e.g. depending on pre-pregnancy body weight and gestational weight gain. According to recommendations, gestational weight gain should be taken into account when determining energy needs for pregnant women. Energy requirement may be different in women whose gestational weight gain should be lower or higher than average values [16]. The protein and fat content was similar, being the highest in pattern 1 where it amounted to 128.6 g for proteins and 75.0 g for fat, and the lowest in pattern 3 — 101.8 g for proteins and 63.4 g for fat. The protein content significantly exceeded the recommended values in all dietary patterns. The highest content of carbohydrates was recorded in the vegetable-fruit diet (dietary pattern 2) (Me = 344.0 g), slightly lower in the cereal-milk diet (dietary pattern 1) (Me = 313.6 g) and the lowest in the cottage cheese-vegetable diet (dietary pattern 3) (Me = 265.8). The content of most minerals exceeded the recommended values in all dietary patterns, it was lower only in the case of iron and iodine. In the cottage cheese-vegetable diet (dietary pattern 3), the content of all analysed minerals was the lowest. The analysis of the consumption of fat-soluble vitamins revealed that the amounts of vitamins A and E were higher than recommended in all clusters. All dietary patterns were characterized by a lower than recommended content of vitamin D, which was approximately 3 µg. The content of water-soluble vitamins was higher than recommended in all dietary patterns. The content of vitamin C exceeded the nutritional standards four times. The percentage of energy from proteins slightly exceeded the recommended values, and the percentage of energy from fat and carbohydrates was within the norms.
DISCUSSION
During the life cycle of a woman, pregnancy is the period when she is most open to changing her behaviour and lifestyle for the benefit of the child’s development. Lifestyle changes include, among others, also the diet correction. The nutritional factor is therefore one of the most important determinants of the appropriate development of pregnancy and the child. Nutritional needs should be analysed individually for each patient, taking into account her age, level of physical activity, lifestyle and, above all, nutritional status [2, 5]. A rational diet during pregnancy prevents complications and ensures appropriate development of the fetus. The implementation of nutritional recommendations in practice consists in adhering to a balanced and varied diet, thus reducing the incidence of both deficiency and excess of energy and nutrients [4–6]. The increased demand for energy (2nd and 3rd trimester) should be fulfilled by increasing the intake of mainly milk and dairy products, lean meat and its products, fish and additional portions of vegetables and fruit [16].
Numerous studies emphasize that the main complication caused by maternal underweight may be low birth weight of the child, which is often associated with an increased risk of cardiovascular diseases and type 2 diabetes [19–24], whereas maternal overweight and obesity may adversely affect the course of pregnancy and the child’s development by increasing the risk of preeclampsia, preterm labour and gestational diabetes. In the case of excess body weight in a pregnant woman, it is more often necessary to perform a caesarean section. Some research reports suggest that maternal overweight or obesity during pregnancy may increase the risk of obesity in a child in later life [25–32]. The nutritional status determined using prepregnancy BMI of the majority of women (76.3%) in our study was appropriate. To assess the nutritional status of the studied women during pregnancy, their weight gain in kg per week was calculated. In all subgroups, the weight gain was above the values recommended by the Institute of Medicine [12]. The highest average weight gain was recorded in the group of women who were underweight before pregnancy (0.56 vs 0.51 kg/week). Weight gain in women with an appropriate body mass index before pregnancy was on average 0.55 kg/week, which was 0.13 kg/week higher than recommended. The lowest average gains of 0.40 kg/week were observed in women with excess body weight before pregnancy, but they still exceeded the recommendations (0.22–0.28 kg/week). The literature describes extensively the relationship between abnormal weight gain in pregnancy and the risk of health complications, both in the mother and in the child [19–21, 23, 33, 34]. In the studied group of women who were underweight before pregnancy, body weight gains were higher than recommended and the highest in the entire group of women. This suggests that during pregnancy they changed their diet, ate larger amounts of food to provide all the necessary nutrients to the developing child. In the studied group of women with overweight and obesity, weight gain during pregnancy was the lowest, but still higher than recommended. This may mean that these women have a more conscious attitude towards the nutritional factor and pay more attention to the selection of products in their diet. Studies by Oken et al. suggest that weight gain in obese women which is lower than recommended has a positive effect on pregnancy outcomes, i.e. it reduces the risk of macrosomia in a child, the risk of premature birth, and even obesity in their offspring at the age of 3 years. [27]. At the same time, weight gain lower than the American guidelines should not be routinely recommended for obese pregnant women. These recommendations should be individualized, taking into account risk factors [35].
The nutritional status is related to the diet. The diets of different population groups can be assessed using various methods, one of them being the identification of dietary patterns, which has attracted an increasing attention in recent years. As a comprehensive method, it is used to determine the relationship between the diet and the nutritional status, which gives a more complete picture of the impact of consumption of various dietary components on health status indicators. In the Polish literature, dietary patterns of women during pregnancy have not been widely described, in contrast to foreign literature, where this topic is more popular. Dietary patterns of pregnant women are most often described in the context of the course of pregnancy, the risk of complications, including gestational diabetes, pregnancy-induced hypertension, birth weight of the newborn, and also in the long-term perspective, i.e. nutritional programming [36–40]. Researchers identifying dietary patterns try to indicate the pattern which is most similar to the nutritional recommendations for pregnant women and compare it with other patterns that significantly deviate from the recommendations. The dietary pattern compliant with the recommendations is most often described as healthy or prudent [41–44], but also health conscious [45]. Thus, defined dietary patterns are characterized by a high intake of vegetables, fruit, oils, whole grains and fish. The patterns which deviate from the recommendations are referred to as traditional or Western and are characterized by a high intake of red meat and its products, potatoes, sugar and sweets, cereal products, fat, except for olive oil, salty snacks, eggs, sauces and sweet drinks. For example, in a Canadian study of 1,545 pregnant women, four dietary patterns were identified. The first one, i.e. healthy pattern, was characterized by high intake of vegetables, including green vegetables, fruit, orange vegetables, oils, white and brown pasta, brown rice, fish and tomatoes. In the second one, named the meat and refined carbohydrates pattern, the more frequent intake of red meat, processed meat, fries, roast and boiled potatoes, and white bread was recorded. The third pattern was characterized by a high intake of beans and pulses, cheese, and vegetable salads and was named the beans, cheese and salad pattern. Women adhering to the fourth pattern named tea and coffee pattern more frequently drank coffee and tea, including with added reduced-fat milk, cream and sugar. The results showed that women adhering to healthy dietary patterns before pregnancy had a lower risk of developing complications such as hypertension [44]. In the Greek study, two dietary patterns were identified in pregnant women and named health conscious and Western. The Western pattern was characterised by a high intake of meat and meat products, potatoes, sugar and sweets, cereals, fats except olive oil, salty snacks, eggs, sauces and sweet beverages [45]. For the sake of comparison, in the Japanese study, the Western dietary pattern was described as a pattern with low intake of non-alcoholic beverages and sweets [46]. This shows that different dietary patterns may have the same names in different studies and vice versa. Some patterns, which were characterised by similar products in different studies, may be named differently. For example, there are many names for the pattern called the Mediterranean diet, such as the Mediterranean-type diet, the Mediterranean diet index, and the alternative Mediterranean diet, but the main components of this diet are the same [47–51]. A study conducted in 10 Mediterranean countries proved that adherence to the Mediterranean pattern of eating during pregnancy results in a better glucose tolerance and a lower incidence of gestational diabetes [51]. The authors of a Dutch prospective study proved that adherence to a traditional dietary pattern during pregnancy, in comparison with a Mediterranean pattern, has a negative impact on blood pressure parameters causing their increase [52]. In Denmark, the adherence to a Mediterranean dietary pattern by pregnant women was associated with a reduced risk of preterm labour [47]. A prospective study involving 13.110 American women showed that the Western dietary pattern was positively correlated with the risk of gestational diabetes, and the prudent dietary pattern, characterised by a high intake of fruit, green leafy vegetables, poultry and fish, showed a negative correlation [41]. Another study found that a prudent dietary pattern was associated with a lower risk of gestational diabetes, especially among women with excess body weight [43]. He et al. also proved that the dietary pattern defined as vegetable pattern was correlated with a lower risk, while the sweets and seafood pattern with a significantly higher risk of gestational diabetes mellitus [53]. It has also been shown that consumption of the DASH diet (high in fruit, vegetables, whole grain cereals, low-fat dairy products, and lower in saturated fat, cholesterol, and sodium 2400 mg/day) for 4 weeks by pregnant women had a beneficial effect on glucose tolerance and lipid profile compared to the control diet [54]. A Norwegian study has shown that pregnant women eating a diet with a high intake of vegetables and plant-based products, including oils, had a lower risk of pre-eclampsia, while a diet with a high intake of meat, sweet drinks and snacks increased this risk [55].
In our study, it can be concluded that none of the identified dietary patterns was fully compliant with the health-promoting pattern described in the current literature. Dietary pattern 1 defined as the cereal-milk diet seems to be the closest to the patterns described in the literature as traditional or Western, due to a high intake of cereals and butter, hard cheese, meat, poultry, cold cuts, and sugar and a low intake of vegetables and fruit. Dietary pattern 2 defined as the vegetable-fruit diet stood out due to the intake of this group of products, but at the same time it was characterized by a higher intake of potatoes, meat and poultry, and a lower intake of cottage cheese, rennet cheese and fermented milk drinks. Dietary pattern 3, defined as the cottage cheese-vegetable diet, was characterized by a higher intake of cottage cheese, as well as milk, cooked vegetables and fish, but also a lower intake of cereal products and butter, as well as meat, poultry and cold cuts.
The frequency of the identified dietary patterns in the three subgroups of the studied women, depending on their pre-pregnancy body mass index, was similar. The differences were slight and statistically insignificant. It should be noted, however, that the most common pattern was dietary pattern 3 defined as the cottage cheese-vegetable diet with the lowest energy value. The analysis of the frequency of individual patterns in the studied women depending on the weight gain during pregnancy revealed a greater differentiation. Dietary pattern 1, i.e. the cereal-milk diet with higher energy value occurred most often in the group of women with excess bodyweight before pregnancy whose weight gain during pregnancy was above the recommendations (75.0%). It means that they should pay more attention to their diet during pregnancy due to the higher risk of complications related to excess body weight in pregnancy. Dietary patterns 1, i.e. the cereals-milk diet and dietary pattern 2, i.e. vegetable-fruit diet occurred most often in the group of women with underweight before pregnancy whose weight gain during pregnancy was in the line with the recommendations and above (40.0% and 53.8% respectively). It is possible that women in this group, who were slim before pregnancy, paid more attention to their diet during pregnancy.
The study has several strengths. All data regarding the diets of studied pregnant women were collected by one qualified person, and verified with the product and food photography album [14], which reduces the risk of incorrect estimation of the size of the consumed portions of food. The study focused on the identification of dietary patterns as a comprehensive method used to determine the relationship between the diet and nutritional status. Diet pattern analysis is considered as a holistic, alternative and complementary approach to assessing the relationship between diet and chronic disease risk by assessing the impact of the overall diet and its complexity. Therefore, the analysis of dietary patterns can be helpful in evaluating dietary recommendations and in explaining the relationship between the consumption of individual dietary components and health when these relations may depend on the dietary pattern. Moreover, the identification of dietary patterns of pregnant women can be the basis for shaping educational programs in childbirth classes. In the literature, there are only few studies describing the dietary patterns of Polish women during pregnancy [56, 57]. Only our study includes the nutrient profile of identified feeding patterns of pregnant women.
However, this study also has limitations. The group of studied pregnant women is not representative, but it is a large sample (n = 392). The studied women are participants of childbirth classes, mostly with higher education. Despite this, the results of the conducted research suggest the need for educational activities in the field of healthy eating patterns during pregnancy.
CONCLUSIONS
Although pregnancy should not differentiate the dietary procedures, including the selection of products, different dietary patterns were identified. In each group of women, regardless of their nutritional status before pregnancy as determined by BMI, the percentage of women adhering to the identified patterns was similar. In the studied women, weight gain during pregnancy was higher than in recommendations/guidelines, being the highest in women who were slim before pregnancy, and lower in women with excess body weight, which was related to their dietary patterns. The method of analysing the nutritional management through identified dietary patterns of pregnant women, correlated with their weight gain, can be a fast and effective way to convince this group of women to adjust their diets for the benefit of the health of the mother and the child, as well as for long-term prediction of the risk of diet-related disease in adulthood of the child. The analysis of the dietary patterns of pregnant women who are participants of childbirth education classes may be helpful in education and modification of the dietary recommendations for this population group, also with regard to supplementation.
Article information and declarations
Data availability statement
All data generated or analyzed during this study are included in this article. The datasets are not publicly available but are available from the corresponding author on reasonable request.
Ethics statement
The study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of the Institute of Mother and Child (Opinion No 10/2019).
Author contributions
Malgorzata Wiech: corresponding author, concept, methodology, acquisition of data, analysis and interpretation of data, visualization, manuscript writing, editing and approval the final manuscript. Ewa Kawaik-Jawor: data curation, formal analysis methodology, visualization, review, editing and approval the final manuscript. Marta Baranska: writing original draft, review and approval the final manuscript. Julia Zareba-Szczudlik: revised article critically. Halina Weker: concept, methodology, writing original draft, review and approval the final manuscript.
Consent for publication
Informed consent was obtained from all participants of the study.
Funding
None.
Conflict of interest
The authors declare that they have no competing interests.
