The consumption of food, energy and nutrients in pregnant women: Differences with respect to smoking habits

Dietary patterns among pregnant women in the west-north of Iran

This study was conducted to assess the food consumption pattern and nutrient intakes of pregnant women residing in Maku-the west north of Iran. In this cross-sectional study, 284 pregnant women (142 from urban area and 142 from rural areas) participated. Subjects were interviewed privately, face-to-face. Dietary intake data was collected using two 24 h recalls and a food frequency questionnaire for 3 months. Mean consumption of grains and dairies was higher in rural women compared to their counterparts in urban areas. Women in urban areas consumed 140 g fruits compared to 248 g consumed by rural women. There were no significant differences regarding consumption of vegetables, pulses, fat and oils between these two groups. All women consumed adequate amount of energy, protein, thiamin and niacin (> 75% RDA). Intake of vitamin B6, folate, vitamins A and D, iron, phosphorus, calcium, magnesium and zinc was not sufficient in these women. Inadequate intake of vitamin C and riboflavin was also reported in urban women. Percentage of energy from carbohydrate, fat and protein was 66, 23 and 11% for urban women, respectively and 68, 20 and 12% for rural women, respectively. Iron intake was lower in urban women compared to rural women. The findings indicated that rural women have better nutritional status than urban women. Future studies should determine factors associated with food consumption pattern in these women.

Beta-carotene concentrations in maternal and cord blood of smokers and non-smokers

BACKGROUND

Smoking in pregnancy can cause a reduction in the transport of beta-carotene across the placenta, consequently reflecting on the concentrations of this micronutrient in the newborn baby.

AIMS

This study determined the concentrations of beta-carotene in maternal blood and umbilical cord blood in a group of smokers and non-smokers.

DESIGN AND SUBJECTS

A total of 215 women and respective newborn babies were selected from a hospital in Joinville city, Brazil, between July and November 2002. Women were divided in two groups according to their smoking habits. beta-Carotene concentration was determined by high-performance liquid chromatography (HPLC). The difference between mean concentrations of beta-carotene in maternal blood and cord blood, in smokers and non-smokers, was determined by analysis of variance (ANOVA). The Student's t-test compared mean concentrations of beta-carotene in maternal blood and cord blood, and the mean ingestion of foods rich in beta-carotene by smokers and non-smokers.

RESULTS

There was a statistical significant difference between the concentrations of beta-carotene in maternal blood (S=0.271 micromol/L, NS=0.450 micromol/L; P=0.001) and cord blood (S=0.028 micromol/L, NS=0.045 micromol/L; P=0.001) in smokers (S) and non-smokers (NS). The mean concentration of beta-carotene was significantly higher in maternal blood (0.398 micromol/L) than in cord blood (0.041 micromol/L) (P<0.001). The intake of foods rich in beta-carotene was lower in smokers, than in non-smokers (P=0.04).

CONCLUSIONS

The concentrations of beta-carotene in maternal blood and cord blood were influenced by the use of tobacco.

Thiamin status during the third trimester of pregnancy and its influence on thiamin concentrations in transition and mature breast milk

Thiamin deficiency remains an important public health problem in some populations. The aim of the present investigation was to study thiamin status during the third trimester of pregnancy and its influence on the concentration of this vitamin in transition (days 13-14 of lactation) and mature breast milk (day 40 of lactation) in a group of Spanish women. The pregnancies and lactation periods of fifty-one healthy women 18-35 (mean 26.7 (SD 3.7)) years old were monitored. Vitamin intake during the third trimester was determined by recording the consumption of foods over 5 d and of the quantities provided by dietary supplements. Thiamin status during this stage of pregnancy was determined by measuring the activation coefficient of erythrocyte transketolase (alpha-ETK). Milk thiamin content was estimated (in 41% of the subjects) by oxidizing thiamin to thiocrome and measuring fluorescence. Subjects with thiamin intakes above that recommended (group H) had more satisfactory serum alpha-ETK coefficients (1.01 (SD 0.19)) than did those with lower intakes (group L) (1.21 (SD 0.30); P<0.05). Mature milk thiamin concentrations were significantly higher in group H subjects (0.59 (SD 0.44) micromol/l) than group L subjects (0.25 (SD 0.07) micromol/l). Subjects with alpha-ETK coefficients >1.25 in the third trimester had significantly lower mature milk thiamin concentration (0.31 (SD 0.10) micromol/l) than did subjects with more satisfactory alpha-ETK levels at this time (0.55 (SD 0.42) micromol/l; P<0.05). The thiamin status of women can be improved since 25.5% of subjects took less than that recommended and 13.7% showed signs of severe deficiency (alpha-ETK >1.25). The influence of maternal thiamin intake on alpha-ETK coefficients and on mature breast milk thiamin concentration is confirmed.

Dietary guidelines for pregnant women

The nutrition of pregnant women is decisive in the course of gestation and the health of both mother and child. However, in the Spanish population, clinical monitoring of nutrition is rare, the control of bodyweight receiving most attention. Many studies show that pregnant women take too much fat and too little carbohydrate, and that intakes of fibre and several trace elements are lower than recommended. Although many people think they know what a correct (varied and balanced) diet is, the concept is often misleading. Generally, they do not match the ideal theoretical framework for achieving an adequate energy profile of the diet. Neither do they facilitate intakes of vitamins and minerals close to recommended levels. Nutrition education programmes are therefore required to explain adequate dietary guidelines to pregnant women, and indeed to all women of childbearing age. Considering the criteria suggested by a number of researchers concerning the number of food portions from each food group that pregnant women should include in their diets, the following guidelines for daily consumption are proposed: 3-4 portions of milk products, 2-3 portions of meat, fish or eggs, and 3 portions of fruit, 4-5 portions of vegetables or greens and 7-8 portions of cereals and legumes (a portion is defined as the amount of food that would be found on an average plateful or the normal units of consumption of a food).