Optimal fetal development and infant outcome depend on availability of specific nutrients during the preconceptual and gestational periods, including the omega-3 long chain polyunsaturated fatty acids (LCPUFAs), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) [
In response to maternal omega-3 LCPUFA intake during pregnancy, infants have improved performance on cognitive and developmental tests [
Health benefits of omega-3 LCPUFA intake in pregnancy may also extend to the mother. The relationship between dietary omega-3 LCPUFA intake and maternal mental health conditions (depressive disorders during and after pregnancy) has been examined. There is evidence that omega-3 LCPUFA intake may benefit women with preexisting depressive illnesses [
There is evidence that omega-3 LCPUFAs also positively affect general pregnancy outcome. Omega-3 LCPUFAs prolong pregnancy duration, reducing the risk of birth before 34 gestational weeks by 31% in normal and 61% in high-risk pregnancies [
These measurable and documented benefits of omega-3 LCPUFA underscore the recommendations of the 2015–2020 Dietary Guidelines for Americans [
DHA and EPA content of major dietary sources of omega-3 LCPUFA1,2.
DHA, |
EPA, |
Number of 4 oz. servings to provide 250 mg |
Oz. to provide 250 mg DHA + EPA | |
---|---|---|---|---|
Bass | ||||
Sea | 492 | 183 | 0.37 | 1.48 |
Striped | 663 | 192 | 0.29 | 1.17 |
Catfish | ||||
Farmed | 64 | 19 | 3.02 | 12.10 |
Wild | 265 | 147 | 0.61 | 2.43 |
Cod | ||||
Atlantic | 136 | 72 | 1.20 | 4.81 |
Pacific | 109 | 39 | 1.69 | 6.76 |
Herring | ||||
Atlantic | 977 | 804 | 0.14 | 0.56 |
Pacific | 781 | 1099 | 0.13 | 0.53 |
Flounder | 123 | 155 | 0.90 | 3.61 |
Salmon | ||||
Atlantic, farmed | 1251 | 977 | 0.11 | 0.45 |
Atlantic, wild | 1264 | 364 | 0.15 | 0.61 |
Pink | 377 | 207 | 0.43 | 1.71 |
Sockeye | 1797 | 395 | 0.11 | 0.46 |
Tilapia | 97 | 5 | 2.44 | 9.74 |
Trout | 599 | 229 | 0.30 | 1.21 |
Tuna | ||||
Bluefin | 1009 | 321 | 0.19 | 0.75 |
Light, canned in water | 223 | 32 | 0.98 | 3.93 |
Yellowfin | 100 | 13 | 2.21 | 8.82 |
White, canned in water | 713 | 264 | 0.26 | 1.02 |
2Nutrient values are estimates and depend on species of fish, total fat content of fish, geographical location, method of raising/harvesting, and cooking. All values are for raw portions and, as such, are overestimates after cooking is considered [
3Number of servings (4 oz.) were calculated to meet 250 mg of omega-3 LCPUFA per day, as recommended for pregnant women by the Dietary Guidelines for Americans (2015–2020) [
These recommendations translate to approximately 250 mg omega-3 LCPUFAs per day and are in line with the recommendation of 200 mg DHA per day set forth by an international panel of experts in an earlier consensus statement [
The Food and Drug Administration and Environmental Protection Agency further specify that servings should be from a variety of fish that have low levels of methylmercury [
During pregnancy, the fetus relies on maternal intake and placental transfer of nutrients to meet developmental demands. Although prenatal vitamins and other vitamins/supplements are marketed to pregnant women, they may not contain omega-3 LCPUFAs or women may not consume them at all or with any regularity [
Previous estimates of dietary omega-3 LCPUFA intake point to low consumption by pregnant women and women of childbearing ages. In a small sample (
Given the role of omega-3 LCPUFAs in infant development, pregnancy outcome, and maternal health, it is important to assess if pregnant women are adhering to the dietary recommendation to include seafood in their diets and, if not, what foods they are choosing to consume instead. Therefore, the aim of the study was to investigate the dietary habits of pregnant women in Baton Rouge, Louisiana, USA. Specifically, we evaluated their consumption of various dietary protein sources.
Geographically, Baton Rouge is located directly on the Mississippi River and approximately 157 miles north of the Gulf of Mexico. As Louisiana is a coastal state and fish are an intricate part of the regional culture and cuisine [
For this observational study, we approached women at an event held for expecting women and their partners at a hospital in Baton Rouge, Louisiana. The free, single-day event was held in October 2015. Women were approached and invited to complete a survey about their dietary habits during pregnancy and respond to a demographic questionnaire; the survey and questionnaire were provided as separate documents. All pregnant women who visited the research booth at the event were invited to participate; the only inclusion criterion was current pregnancy and there was no selection bias. Our efforts resulted in 221 completed surveys and questionnaires; the responses from each were separated at the time of completion.
Compensation for study completion was entry into a raffle for free baby books and other materials for expecting families. Women provided their first name and telephone number on a separate piece of paper; this paper was not attached to the survey or questionnaire. When a name was drawn in the raffle, the woman was contacted by a call or text and returned to the booth to pick up her raffle prize. All contact information was destroyed at the conclusion of the convention.
The survey included a statement that completion of the survey constituted consent to participate and participation were voluntary. All procedures involving human subjects were approved by The Louisiana State University AgCenter and Woman’s Hospital Institutional Review Boards.
Contact and demographic information were not attached to the survey and, as such, responses were anonymous. The women were allowed to complete their survey and the questionnaire and provide their contact information on an individual clipboard standing away from the table at which the researchers were stationed.
The survey was designed to be completed by participants in approximately 5 minutes with minimal input or direction from the researchers. Women were instructed to complete the survey in accordance with their usual dietary habits during pregnancy. The survey has not been previously validated and was developed as a tool to provide preliminary, descriptive data that provides a direction and foundation upon which to build for future research.
The survey contained four sections (“protein sources”), labeled and ordered as follows: “Beef,” “Chicken,” “Fish,” and “Pork.” Each section included a list of foods commonly consumed for that respective protein source; these foods were subjectively chosen by the researchers.
“Beef” included, in order, “Steak,” “Hamburger,” “Stew meat,” “Brisket,” and “Roast.” “Chicken” included, in order, “Wings,” “Breast,” and “Legs.” “Fish” included, in order, “Canned tuna,” “Tuna steak,” “Tilapia,” “Salmon,” “Cod,” “Catfish,” “Swordfish,” “Trout,” “Bass,” “Flounder,” and “Herring.” “Pork” included, in order, “Chop,” “Tenderloin,” and “Roast.”
More specific information about the foods and food preparation was not sought. For example, “Steak” could include any cut of steak, “Salmon” could include any species of salmon, and “Wings” could include any preparation and/or cooking style of chicken wings.
Each question had six predefined responses to assess how frequently the women were consuming each: “Never,” “Once/week,” “2-2+/week,” “Once/month,” “2-3/month,” and “4-4+/month.” The majority of women checked only one box per food; however, if multiple or none of the boxes were checked, that data point was entered as missing.
As the primary focus of our study was fish consumption by pregnant women, we constructed our survey to include a variety of fish, including those that are poor and good sources of omega-3 LCPUFAs and those that are indigenous and nonnative to the area (canned tuna, tuna steak, tilapia, salmon, cod, catfish, swordfish, trout, bass, flounder, and herring).
The demographic questionnaire, included as a separate document, included questions about participant age, ethnicity, education level, and if she was a first-time mother. All documents were provided in print.
Our survey did not indicate the size of a serving. Rather, we asked how often the women consumed each food and assumed portion sizes for each. In speculating whether pregnant women are meeting the omega-3 LCPUFA recommendations by dietary fish intake, we assumed each serving to be 4 oz.
This assumption was based on a table in the 2015–2020 Dietary Guidelines for Americans [
Demographic data (
Demographics of the survey population.
% of women, |
|
---|---|
Age, years | |
<20 | 3.2 |
20–25 | 29.0 |
26–30 | 37.3 |
31–35 | 23.0 |
36–40 | 6.9 |
No answer | 0.5 |
|
|
Education | |
Some high school | 3.2 |
High school graduate | 6.5 |
Some college | 23.5 |
2-year degree | 8.8 |
4-year degree | 29.0 |
Graduate degree | 28.6 |
No answer | 0.5 |
|
|
Ethnicity | |
African American | 20.3 |
Caucasian | 71.4 |
Hispanic | 2.3 |
American Indian | 0.5 |
Asian | 4.6 |
Multiracial | 0.5 |
No answer | 0.5 |
|
|
First-time mom | |
Yes | 78.5 |
No | 21.5 |
No answer | 1.4 |
Of the women approached (estimated 250–275), 221 completed the survey. The average response rate for each food was 92%. Women responded to the frequency with which they ate stew meat least often (i.e., did not answer the question; 88% response rate) and chicken breast most often (96% response rate).
Twenty-two percent of women reported consuming fish, when consumption of all individual varieties was averaged (Figure
Consumption rate and frequency of protein sources by pregnant women.
The most common consumption frequency for catfish, tilapia, canned tuna, and salmon was once per month, followed by once per week. Consumption rate and frequency for each fish variety are presented in Figures
Consumption rate and frequency of the more consumed fish varieties by pregnant women.
Consumption rate and frequency of the less consumed fish varieties by pregnant women.
Consumption rate for beef, chicken, and pork, when all foods were averaged within protein source, was 71, 74, and 65%, respectively. Hamburger, chicken breast, and pork chops were the most consumed foods for each protein source, with 90, 92, and 63% of women reporting that they consume each, respectively. Brisket, chicken legs, and pork roast were the least consumed foods for each protein source, with 52, 65, and 58% of women reporting that they consume each, respectively.
Women most commonly reported intake of the most consumed beef (hamburger) and chicken foods (chicken breast) at a frequency of once or at least twice per week. A consumption frequency of once per month was the most common response for the least popular beef, chicken, and pork foods (brisket, chicken legs, and pork roast, resp.). The most popular pork food (pork chops) was most often consumed at a frequency of once per month. Consumption rate and frequency of consumption for the most and least consumed foods, grouped by protein source, are presented in Figures
Consumption rate and frequency of the most consumed foods for each protein source by pregnant women.
Consumption rate and frequency of the least consumed foods for each protein source by pregnant women.
The two most commonly consumed fish varieties by our population (catfish and tilapia) have significantly lower concentrations of omega-3 LCPUFAs than the varieties which were rarely consumed (Table
To meet the recommendation of an average intake of 250 mg omega-3 LCPUFA per day [
Dietary incorporation of canned white tuna and/or salmon at a frequency of twice per week would satisfy recommended levels of omega-3 LCPUFA intake, exclusive of intake of other varieties (Table
The Food and Drug Administration and Environmental Protection Agency advise pregnant women and women of childbearing ages to avoid consumption of tilefish from the Gulf of Mexico, shark, swordfish, and king mackerel due to their high methylmercury content [
In the current study, consumption rate of beef, chicken, and pork was at least threefold higher than that of fish. The most consumed fish varieties were consumed at a frequency that was similar to or less than that of the least consumed beef, chicken, and pork foods. Clearly, when choosing a protein source, pregnant women are opting to consume beef, chicken, and/or pork in favor of fish.
Our data is in line with that of a previous investigation [
There is a stark difference in dietary seafood habits of pregnant women between the North American countries of the United States and Canada and that of other regions.
A large, observational study [
A comparison of two studies assessing pregnant women in Denmark [
In Spanish populations, 86% of pregnant women reported consuming at least 12 seafood meals per months [
Although those North American populations outlined above [
Given the wide availability of seafood in coastal regions [
The international disparity in seafood intake reflects the findings of a 2010 study, which qualitatively determined knowledge and behavior of pregnant women (
Two studies [
It is important to note that, for each study outlined above, dietary data were collected from and reported in a variety of ways. For comparison with our results, we converted the data to servings per month by assuming a serving was 4 oz., if the data were reported as g consumed per unit of time. We note that dietary data were collected by various methods (food frequency questionnaires, 24-hour dietary recalls) but assumed each method to be equal. These data manipulations could affect the precision of our comparisons.
Future studies should assess whether pregnant women and women of childbearing ages have knowledge of the dietary recommendations for seafood consumption. These efforts should aim to elucidate if (1) there are specific groups of pregnant women who are less likely to meet dietary fish recommendations and (2) why these women fail to meet those recommendations.
Replication of the current survey across different geographic areas would also provide insight into the effect of coastal versus inland location on fish intake and dietary protein preferences.
Our survey was conducted in a convenience sample and since the survey and demographic questionnaires were not connected, we are unable to examine potential group differences or correlations between demographic parameters and responses.
We assumed values for portion sizes. Although this assumption does not affect our observations of dietary habits, it does affect the precision of our calculations in regard to whether pregnant women are meeting omega-3 LCPUFA recommendations or not. Furthermore, we did not consider how foods were prepared. Certain cooking styles are related to differences in the fatty acid content of the resulting product [
The characteristics of our study population differ from those published by the United States Census Bureau [
It is important to note that educational attainment data from the United States Census Bureau data reflects that of the population aged 25 years and older, without specificity to gender. Approximately 32% of our population was aged 25 years or less. Additionally, the ethnic breakdowns provided by the United States Census Bureau data reflect that of the entire population in that region without regard to age, gender, or pregnancy status. These discrepancies make it difficult to draw conclusions on the generalizability of our data.
These data reveal that pregnant women in Baton Rouge, Louisiana, USA, are not meeting dietary recommendations for seafood consumption and, therefore, likely do not consume adequate amounts of omega-3 LCPUFAs for optimal maternal health, fetal development, and infant outcome. These data also reveal the protein sources and specific foods that pregnant women are consuming in lieu of fish.
The apparent deficit in omega-3 LCPUFA intake has major implications during and after pregnancy and should be addressed with intensified efforts to provide nutrition and lifestyle education to pregnant women and women of childbearing ages.
Although our data indicate pregnant women, in general, do not meet dietary seafood recommendations, future research will help us better understand the habits of pregnant women, directing us in our development of targeted education efforts which emphasize the importance of consumption of fish low in methylmercury during pregnancy.
There are no competing interests regarding the publication of this paper.
The authors would like to acknowledge Woman’s Hospital for allowing them to conduct their survey and the women who participated. Funding was received from Louisiana State University and Louisiana State University Agricultural Center to support the graduate students collecting data and preparing the paper.