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Original Research |
Suzanne Tough, PhD, Department of Pediatrics, Faculty of Medicine, University of Calgary, the Department of Community Health Sciences, Faculty of Medicine, University of Calgary, and the Decision Support Research Team, Calgary Health Region, Calgary, Alberta, Canada
Karen Tofflemire, MSc, Decision Support Research Team, Calgary Health Region, Calgary, Alberta, Canada
Margaret Clarke, MD, Department of Pediatrics, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
Christine Newburn-Cook, PhD, Faculty of Nursing, University of Alberta, Edmonton, Alberta, Canada
Reprint Requests: Suzanne Tough, PhD, Department of Pediatrics, Alberta Childrens Hospital, 1820 Richmond Rd SW, Room 3013, Calgary, AB, Canada, T2T 5C7, Tel: 403-943-2272, Fax: 403-943-7214, Email: suzanne.tough{at}calgaryhealthregion.ca
Received: October 13, 2005.
Revised: January 20, 2006.
Accepted: January 24, 2006.
| Abstract |
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Objectives: To describe and assess changes in patterns of womens alcohol use between the preconception, pre-pregnancy recognition and post-pregnancy recognition time periods. Secondly, to describe characteristics of women consuming any alcohol and those binge drinking during pre- and post-pregnancy recognition periods.
Methods: Computer assisted telephone interviews were conducted with 1042 women who had recently delivered a baby in urban Alberta, Canada. Differences in consumption patterns between time periods were analyzed using analysis of variance and Chi-square tests. Characteristics of those drinking both before and after pregnancy recognition were analyzed using logistic regression.
Results: Eighty percent of women reported alcohol consumption pre-conceptually, 50% pre-pregnancy recognition and 18% post-pregnancy recognition. Binge drinking was reported by 32%, 11% and 0% for preconception, pre-pregnancy recognition and post-pregnancy recognition periods, respectively. Alcohol consumption patterns (i.e., the mean number of drinks per drinking day and week) did not differ significantly between preconception and pre-pregnancy recognition periods but did significantly drop after pregnancy recognition (p<0.001). Alcohol use during the period of pre-pregnancy recognition was higher among those not planning a pregnancy, not using assisted reproductive technology, of higher income, without a history of miscarriage, who were Caucasian, and who used tobacco. Binge drinking was higher among women not planning a pregnancy, those who used tobacco, and those with low self-esteem. Women continuing to drink small amounts of alcohol after pregnancy recognition were more likely to be between the ages of 3039 years, be Caucasian and use tobacco.
Conclusion: Preconception and "well-women" counseling strategies would be improved by increasing the emphasis on the risks of alcohol use during periods when pregnancy can occur.
Key Words: Alcohol consumption Preconception counseling Pregnancy
There are limited data on alcohol use over the course of pregnancy, and since no pattern of consumption or lower limit of alcohol exposure has been found to be safe, medical guidelines recommend abstinence during pregnancy and while attempting to conceive.1,2 In 1994, US surveys suggested that 14% of pregnant women reported alcohol use in the past month, and recent Canadian data revealed that 14.6% of mothers reported drinking any alcohol during pregnancy.3,4 Unfortunately, accurate assessments of alcohol use may be hampered by the social stigma associated with reporting alcohol consumption, different methods of assessment and unclear definitions of when pregnancy began.
Indeed, recent evidence suggests that, depending on the screening tool utilized, rates of alcohol use among pregnant women range between 21% to 70%.5 In addition to more accurate information about the prevalence of maternal alcohol use, the development of relevant preconception health strategies also requires an understanding of when fetal alcohol exposure is most likely to occur and how women currently behave in relationship to guidelines recommending alcohol abstinence during pregnancy.
In preparation for a healthy pregnancy, women are encouraged to review their medication use, their folic acid intake and their lifestyle choices, such as tobacco use and alcohol consumption.6 A recent study found that 98% of Canadians believed that the more alcohol a pregnant woman drank, the more likely it would be that the baby would be harmed.7 Although the majority of women reduce alcohol consumption when they realize they are pregnant, this may not occur until well into the first trimester.8
Prenatal alcohol exposure is one of the leading causes of neurodevelopmental deficits in children, including those of fetal alcohol spectrum disorder (FASD).9,10 The effects of alcohol on the fetus are likely influenced by the timing and amount of alcohol consumed, as well as by maternal metabolism and fetal genetics.11 Features of fetal alcohol syndrome (FAS), a collection of the most severe abnormalities caused by moderate to excessive maternal alcohol consumption, include pre- and postnatal growth deficiencies, characteristic craniofacial dysmorphology and varying degrees of central nervous system dysfunction.12,13 Equally debilitatating are mental and behavioral impairments that may occur in the absence of craniofacial abnormalities.10 The estimated global incidence of FAS is 0.97 per 1000 live births.14
When women are asked to describe their lifestyle habits during pregnancy, the beginning of pregnancy is often poorly defined.15,16 The accuracy of any overall measure of alcohol consumption during pregnancy is dependent on the individuals interpretation of when pregnancy began and may also be influenced by recall bias. Some women will report on consumption with reference to the time in which they knew they were pregnant, while others may report from the time of conception.8 Consequently, there is a lack of clear information on womens alcohol consumption during the early period of embryonic development.
It was hypothesized that the majority of women do not change their alcohol use patterns between the periods of preconception and pregnancy recognition, potentially exposing the fetus to alcohol in the early developmental stages. The purpose of this study was to assess and describe the changes in the patterns of womens alcohol use between the periods of preconception, pre-pregnancy recognition and post-pregnancy recognition, particularly as they relate to pregnancy planning. Secondly, this analysis sought to describe characteristics of women who consume any alcohol and those who binge drink during the periods of pre- and post-pregnancy recognition.
| Methods |
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Participants were interviewed over the telephone by two female interviewers with content training related to maternal and child health. No incentive to participate was offered. This investigation received ethics approval from the University of Alberta and the Conjoint Ethics Board at the University of Calgary and the Calgary Health Region. All participants provided written consent (focus groups and pilot testing) or verbal consent (telephone interview) prior to participation.
Survey
Based on information from focus groups, previous surveys and expert input, a survey was designed specifically for this study. The questions were pilot tested with women of childbearing age who were not part of this study. These results were used to ensure that the questions were clearly written and non-offensive, that the duration of the survey was acceptable, and to resolve unclear wording. The survey contained the following sections: 1) socio-demographic characteristics of the woman and her partner, including education, employment, and income; 2) lifestyle factors, including tobacco, alcohol, and drug use; 3) medical and reproductive history from the current and past pregnancies; 4) factors women considered prior to starting their family, such as financial stability and career goals; 5) knowledge of pregnancy-related risks, such as increasing maternal age and alcohol use; and 6) self-esteem, measured by the Rosenberg Self-Esteem Scale.17
The Rosenberg Self-Esteem Scale generally has high reliability for assessing self-esteem; test-retest correlations are typically within the range of 0.82 to 0.88.18 Scores range from 0 to 40, with higher ones indicating more positive self-esteem. However, because self-esteem is a generally stable characteristic in adults, it is not easily manipulated as an outcome.18,19 Therefore, we classified our results as being above or below the median score.
The face and content validity of the survey was ensured through focus group testing, pilot surveys, and review by medical experts. Data were collected by two experienced interviewers using a computer-assisted telephone interview over a 15-month period between July 2002 and September 2003. Data were collected outside of a clinical context in a non-threatening way by interviewers unfamiliar with the medical history of the participant to minimize bias and more accurately assess patterns of alcohol consumption prior to pregnancy recognition.20 Interviews were closely monitored by the project coordinator who was available to the interviewers at all times. Participants took up to 40 minutes to complete the surveys.
Specific alcohol measures collected on the survey
The pre-pregnancy recognition period was defined as the time period in which a woman was pregnant but had not yet recognized the pregnancy. This time period was calculated in weeks of gestation according to the answer provided to the following question, "How many weeks pregnant were you when your pregnancy was confirmed either as a result of a missed period, a home pregnancy test, or by confirmation from your physician or midwife?"
Participants were asked 19 questions related to alcohol consumption. Frequency of alcohol consumption was assessed by asking, "How many times per week did you usually have an alcoholic drink?" The quantity of alcohol was assessed by asking, "On the days that you had an alcoholic drink, how many drinks did you usually have?" One standard alcoholic drink was defined as one 341 ml (12 oz) bottle of beer, one 341 ml (12 oz) cooler or cider, one 142 ml (5 oz) glass of table wine (12% alcohol), or one 43 ml (1.5 oz) serving of spirits. Measures of quantity and frequency of alcohol consumption were obtained for three separate time periods: 1) 6 months prior to pregnancy, 2) the pre-pregnancy recognition period, and 3) the post-pregnancy recognition period. Questions regarding binge drinking were also asked for these three time periods. Binge drinking was defined as the consumption of 5 or more drinks during a 24-hour period. Additional questions pertaining to participants discussions with their physicians concerning alcohol consumption and pregnancy were also asked.
Statistical analysis
For alcohol consumption patterns within each period of interest, women were categorized as either low or high-risk drinkers. High-risk drinkers were defined as women consuming, on average, nine or more drinks per week and/or participating in binge drinking.21 High or low-risk drinking habits, as well as the proportion of women participating in binge drinking were compared between preconception, pre-pregnancy recognition and post-pregnancy recognition periods using a Chi-square test. Additionally, the mean number of drinks per drinking day (i.e., the quantity of alcohol consumed), the mean number of drinks per week (i.e., the frequency of alcohol consumption) and the mean number of binge drinking episodes were compared between the three time periods using a one-way analysis of variance followed by a multiple comparisons procedure using the Scheffe method. Additionally, the mean number of drinks consumed per drinking day was compared between those who planned a pregnancy and those who did not plan a pregnancy using an independent t-test. Results were considered statistically significant if p
0.05.
Maternal characteristics of non-drinkers (i.e., women completely abstaining from alcohol) and drinkers (i.e., those consuming any alcohol) were compared for pre- and post-pregnancy recognition time periods using Chi-square tests. Data were also analyzed comparing non-binge drinkers (i.e., those without binge episodes) and binge drinkers. A difference was considered statistically significant if p
0.05. Subsequently, three logistic regression models were created using a forward method to describe the independent characteristics of women who were drinkers compared to those who were not drinkers. One model was created for drinkers compared to non-drinkers during the pre-pregnancy recognition period, another model for drinkers compared to non-drinkers during the post-pregnancy recognition period, and another for binge drinkers compared to non-binge drinkers during the pre-pregnancy recognition period. Confounding and interaction of variables were evaluated. Variables were entered into the model building process in the following order: planning of pregnancy, social/environmental factors, prenatal history, and lastly, demographic predictors. Adjusted odds ratios and 95% confidence intervals were calculated.
| Results |
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Alcohol consumption patterns
Ninety-nine percent of the participants knew alcohol was not recommended during pregnancy. Eighty percent reported consuming some alcohol 6 months prior to the pregnancy, with approximately 60% of these women reporting patterns of low-risk drinking and 40% reporting binge drinking. Fifty percent reported drinking some alcohol during the pre-pregnancy recognition period, with 73% of these women reporting low-risk consumption patterns and 22% reporting at least one occasion of binge drinking. Eighteen percent of the participants reported drinking some alcohol after recognition of the pregnancy (all low-risk patterns), with none of these women reporting binge drinking (table 2
).
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Forty-seven percent of participants who were planning for pregnancy consumed some alcohol during the period of pre-pregnancy recognition compared to 53% of those not planning for pregnancy. Table 3
compares the mean number of drinks per drinking day between those who planned for pregnancy and those who did not plan. Among those consuming any alcohol in the 6 months prior to pregnancy, women who were planning a pregnancy drank significantly less than those not planning (1.98 vs. 2.74 drinks per occasion). Among those who consumed alcohol during the period of pre-pregnancy recognition, those who planned a pregnancy drank significantly less than those who did not plan (2.21 vs. 2.65 drinks per occasion). There were no differences noted in the amount of alcohol consumed once the pregnancy was confirmed between those who did or did not plan a pregnancy.
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When a multivariate model was developed to assess the independent effect of predictor variables, it was found that participants who did not plan the pregnancy were 2.3 times more likely than those who did plan the pregnancy to consume alcohol during the period of conception (table 4
). Annual income of more than $100,000, non-use of assisted reproductive technology, no previous miscarriages, tobacco use and being Caucasian all predicted an increased likelihood of alcohol consumption during the period of conception (table 4
). There were no interaction effects.
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When a multivariate model was developed to assess the independent effect of predictor variables, it was found that participants who did not plan the pregnancy were two times more likely to binge drink during the period of pre-pregnancy recognition than those who did plan the pregnancy (table 5
). Tobacco use and having low self-esteem also predicted binge drinking before pregnancy recognition (table 5
). No interaction effects were found.
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When a multivariate model was developed to assess the independent effect of predictor variables, it was found that being between the ages of 30 and 39 years, using tobacco and being Caucasian all predicted an increased likelihood of alcohol consumption post-pregnancy recognition (table 6
). No interaction effects were found.
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| Discussion |
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The early stages of embryonic development are important periods for healthy development of the infant. Animal studies have highlighted the vulnerability of the central nervous system to ethanol-induced cytotoxicity at different embryonic stages.25 Mouse embryos exposed to ethanol in utero on gestational day 7, which is equivalent to the third week of human gestation, exhibited craniofacial and midline forebrain deficiencies associated with FAS.26,27 In our study, the average length of time between conception and pregnancy recognition was 5 weeks. During this pre-pregnancy recognition period, there is sufficient opportunity for alcohol to potentially impact fetal development.
Although the majority of women in the current study planned for pregnancy, other studies have found that unplanned pregnancies represent 49% to 55% of all pregnancies.28,29 It should be noted that for the current study, the planning status of pregnancy was defined separately from the intended status of pregnancy. Intendedness reflects attitudes toward a pregnancy such as desire and timing, while planning reflects behavior, such as using birth control at the time of conception.30 The current study found that the majority of the women were not only planning for pregnancy (80.3%) but also desired having the child (90.3%) and felt the timing for having a child was convenient (90.8%). When pregnancies are unplanned, mothers are less likely to receive preconception and prenatal care.31,32 Additionally, babies born to mothers who did not intend to become pregnant are at an increased risk for exposure to harmful substances including tobacco and alcohol.33 Therefore, it would seem that the planning status of pregnancy is an important construct for "well women" and preconception program planners and researchers.34
In this study, unplanned pregnancy was found to be associated with both binge drinking and higher average alcohol consumption (p<0.05). Likewise, other studies have shown that binge drinking is associated with an increase in the risk of unplanned and unprotected sexual activity.35,36 Thus, for women who are high-risk drinkers, including binge drinkers, counseling should address contraception, as well as a reduction in alcohol consumption.37
Almost half of all women in this study who were planning for pregnancy consumed some alcohol during the period of pre-pregnancy recognition. Furthermore, those who continued to drink during this period of pre-pregnancy recognition did not change the amount of alcohol consumed per drinking day from the amounts consumed 6 months prior to pregnancy. The finding that most women were planning a pregnancy but many did not abstain from alcohol nor reduce consumption patterns while trying to conceive lends support to the need for improvements in preconception and "well women" counseling strategies.
Despite the fact that most women recognize that alcohol use during pregnancy is not advised, women appear to be uninformed of the potential consequences of alcohol exposure prior to pregnancy recognition. With increased emphasis on the risks of alcohol use when planning a pregnancy, preconception and "well women" counseling strategies may reduce the risk of unintended prenatal alcohol exposure.
Although it has been noted by medical professionals that preconception care can be beneficial to women of childbearing age and may have a positive effect on pregnancy outcome,38 barriers to the implementation of this care exist. Such barriers include a lack of time and financial resources to provide preconception counseling, a perceived lack of patient interest, a shortage of providers and limitations in provider training in the areas of addictions and substance abuse.38,39 Furthermore, the mechanism by which preconception counseling can influence alcohol use during the preconception period and the early stages of pregnancy has yet to be identified. In a recent Danish study,40 it was noted that womens attitudes and actions concerning alcohol consumption during pregnancy were independent of their knowledge about the subject, a finding also confirmed in the present study. The Danish authors question whether pregnant women, and possibly healthcare professionals, are completely convinced that total abstinence is necessary during pregnancy. Indeed, a recent Canadian study found that those physicians recommending abstinence from alcohol versus moderate alcohol consumption during pregnancy were more likely than those not recommending abstinence (p<0.05) to state that there is enough solid information about alcohol use and that clients are interested in the discussion of alcohol use.39
Several limitations exist within this study. In particular, ascertainment of alcohol consumption is very difficult as it is subject to over- and underestimation. As such, there are conflicting views on how and when it is best to interview a woman regarding alcohol exposure in pregnancy. Pregnant women are usually counseled not to use tobacco, alcohol or other drugs, and therefore may be more liable to misreport exposures.41 As this was a self-report survey, response bias may have influenced the reported data. However, the data were collected by non-clinical interviewers, were not linked to clinical care, and were not shared with health care providers or family members which improves the chance of unbiased reporting.17
In addition, this was a retrospective study, so results should be interpreted in light of evidence that suggests that women who are interviewed retrospectively report higher levels of drinking during pregnancy than those who are interviewed antenatally.41,42 Finally, these data represent a sample of urban, mainly Caucasian women, and findings may not be generalizable to all populations. Repetition of this study in geographically and economically diverse areas with inclusion of a qualitative component to better understand the factors influencing alcohol use prior to pregnancy recognition may be helpful in the development of intervention programs or public health initiatives.
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| Acknowledgments |
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