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Healthy lifestyle behaviours in pregnancy: A prospective cohort study in Ireland

02 December 2015
Volume 23 · Issue 12

Abstract

Background:

Women attempting to conceive and those in early pregnancy are advised to alter their lifestyles to achieve and maintain a healthy pregnancy. This study aimed to determine women's reported health behaviours during pregnancy to identify ‘at risk’ groups of women and their pregnancy outcomes.

Method:

A cohort study of 907 women who booked for antenatal care and birth in a large maternity hospital in Dublin, was undertaken from 2010–2011. Eligible women completed an interview at the first visit, a postal questionnaire during the third trimester, and were followed-up until birth and hospital discharge.

Results:

Over 80% of women were found to have factors contributing to an unhealthy lifestyle during the first and third trimester of pregnancy. Clustering of unfavourable factors was evident, with 47% of women engaging in two or more unhealthy lifestyle behaviours during pregnancy. Women of Irish nationality, aged 35–39 years, or who had private health care, were identified as being more likely to have favourable factors for a healthy pregnancy. Women were more likely to engage in healthy lifestyle behaviours during the third trimester if they were having their first baby. Women with healthy lifestyles in pregnancy had better perinatal outcomes than unhealthy women.

Conclusion:

Many women continue to make unhealthy lifestyle choices during pregnancy despite guidelines that recommend healthy behaviours in pregnancy. The ongoing challenge for health professionals is to encourage healthy behaviour modification in women who are planning to conceive or who are already pregnant, particularly young women and those with an unplanned pregnancy.

Women's lifestyle choices before and during pregnancy can have significant links to the health of both the mother and her unborn child (O'Keeffe et al, 2013). Women attempting to conceive and those in early pregnancy are encouraged to alter their lifestyles to achieve and maintain a healthy pregnancy (McKnight, 2013). Optimum pregnancy and infant health outcomes are associated with non-smoking, avoidance of alcohol consumption before and during pregnancy, a healthy balanced diet, regular exercise and compliance with periconceptional folic acid supplementation (Mullally et al, 2011; Health Service Executive (HSE), 2013; Murphy et al, 2013a; 2013b). Advice on lifestyle behavioural change in preparation for and during pregnancy is widely available from health professionals, magazines, television and the internet.

Pregnancy is an important time in a woman's life and maternal health is paramount. Maternal cigarette smoking is one of the most important modifiable lifestyle choices women can make during pregnancy. Smoking during pregnancy is associated with poor pregnancy outcomes including low birth weight and intrauterine growth restriction (IUGR), preterm birth and placental abruption (Pollack et al, 2000; McCowan et al, 2009; Murphy et al, 2013b). Consuming alcohol during pregnancy, even in small amounts, is also known to have both immediate and long-term adverse health outcomes for the developing baby. Prenatal alcohol exposure has been associated with preventable adverse outcomes including miscarriage, premature birth, stillbirth, IUGR, behavioural problems and cognitive deficits (Albertsen et al, 2004; Henderson et al, 2007; O'Leary et al, 2009; Mullally et al, 2011; Patra et al, 2011; Murphy et al, 2014; Nykjaer et al, 2014). In Ireland, to limit the risk of such adverse health outcomes to the baby, pregnant women or those planning a pregnancy are advised not to smoke and to avoid consuming alcohol (HSE, 2013).

A healthy diet is another important part of a healthy lifestyle for pregnant women and the developing fetus (National Institute of Health and Care Excellence (NICE), 2010). Maternal nutrition at conception and during pregnancy influences the growth and development of the fetus. Women with poor nutrition are at an increased risk of cardiovascular disease, high blood pressure and obesity (HSE, 2013). Obese pregnant women are at an increased risk of developing gestational diabetes mellitus (GDM), which further increases complications in pregnancy (Dennedy and Dunne, 2010; NICE 2010). These risks include birth weight above the 90th centile for gestational age, increased need for caesarean birth, clinical neonatal hypoglycaemia, premature delivery, shoulder dystocia, hyperbilirubinemia and pre-eclampsia. Improved diet and lifestyle regimens can potentially decrease these risks.

Recommendations for nutritional intake during pregnancy remain largely the same as those outside of pregnancy, with specific precautions in relation to raw eggs and unpasteurised dairy produce (Bord Bia Irish Food Board, 2015). Pregnant women are advised to follow the food pyramid (HSE, 2012), however there are some additional considerations where intake of certain nutrients should be increased, including iron, calcium, vitamin D and folic acid (HSE, 2013). Taking folic acid is an important lifestyle change that women who are trying to conceive or who are already pregnant can make (McGuire et al, 2010). Neural tube defects (NTDs) are severe abnormalities of the central nervous system that occur as a result of abnormal development in the 3rd and 4th weeks of gestation. Studies have shown that periconceptional folic acid can reduce both the incidence and recurrence of NTDs (Wilcox et al, 2007; Beaudin and Stover, 2009). In Ireland, all women who are pregnant or planning a pregnancy are advised to take 400 mcg of folic acid daily (HSE, 2013).

Along with dietary changes that are encouraged during pregnancy, exercise is also crucial (NICE, 2010). Regular physical activity provides an abundance of health benefits to women including both physical and mental wellbeing (Cioffi et al, 2010). Exercising while pregnant can help women to cope better during their pregnancy and the birth, as well as being a stress-reliever. Pregnant women should be encouraged to begin or continue moderate exercise before and after conception (NICE, 2008).

Although there is some information about the prevalence and predictive factors of health behaviours among women in Ireland, the aim of this study was to further investigate women's reported health behaviours (diet, exercise, alcohol, smoking and folic acid use) during pregnancy and to identify ‘at risk’ groups of women and their pregnancy outcomes.

Methods

This prospective cohort study took place in a large Dublin maternity hospital between November 2010 and December 2011. The hospital booked more than 9500 women for maternity care in 2010. Women were eligible to participate if they had a singleton pregnancy, were aged 18 years or over and understood English. Women were excluded from recruitment into the study for the following reasons: multiple pregnancy, language barrier, illiteracy, late booking, or if they knew they would not give birth in the study site.

The aim of recruitment was to invite every eligible woman to participate in the study; however, due to resource limitations and the range of settings for booking visits, a pragmatic approach was used by the research staff to recruit from settings that had the greatest numbers of women booking on a given day. An initial sample size of 1000 participants was planned, based on analyses from a previous study of alcohol exposure during pregnancy (Murphy et al, 2013a).

Data were collected in three phases; firstly at the booking visit by a structured interview, and secondly, during the third trimester of pregnancy by a self-administered postal questionnaire. The sample size was inflated to 1300 when a lower response rate to the third trimester questionnaire became apparent. Finally, data were collected on the birth and postnatal period up until first hospital discharge.

Ethical approval

The study received research ethics and data protection approval from the Coombe Women and Infants University Hospital's research ethics committee: Study No. 22-2009.

Recruitment

A list of women booking each day was obtained by the members of the research team. Eligible women were given an information leaflet about the study as they waited for their booking appointment in the antenatal clinic. If interested in participating in the study, women made contact with a member of the study team. Consent to participate was discussed and written consent was obtained. To facilitate completion of the recruitment interview, women were taken to a quiet area. This was to encourage the women to be honest when answering questions of a sensitive nature. The structured interview took between 5–10 minutes on average to complete. When the interview was complete, women were thanked for their participation and reminded that they would be receiving a third trimester postal questionnaire when they reached 28–32 weeks pregnant. The postal address of participants was confirmed at this point. To protect confidentiality, questionnaires were anonymised by allocating each participant a unique study number. To facilitate follow-up, corresponding names were stored separately in a locked office with access only by members of the research team. Recruitment continued until the sample size of 1300 was achieved.

Data collection

Information was gathered on lifestyle behaviours during pregnancy including diet, exercise, folic acid use, alcohol intake, smoking and infant feeding intention. The current study focused on determining women's reported lifestyle behaviours during the first trimester and third trimester of pregnancy.

The interview schedule was developed by the multidisciplinary team. A comprehensive set of questions was devised by the multidisciplinary team, consisting of questions about diet, exercise, folic acid use, alcohol intake, smoking and infant feeding intention.

The third trimester postal questionnaire was sent to participants when they reached 28–32 weeks of pregnancy. The pregnancy status of all recruited women was checked prior to sending the questionnaire. At this stage, 71 women were removed from the cohort due to miscarriage, molar pregnancy, previously unknown multiple pregnancy, intrauterine death or a preference not to participate further. The remaining 1220 eligible women were sent a third trimester questionnaire. To encourage women to return the questionnaire, a prepaid return address envelope was also sent.

One week after sending out the questionnaires, a reminder telephone call was made to women, and sometimes women arranged to meet a member of the research team to return the questionnaire while attending antenatal visits in the hospital. Follow-up telephone calls were made to approximately 300 women. In total, 907 questionnaires were returned. Women who booked for antenatal care but birthed elsewhere were not included in the final cohort. Finally, data in relation to perinatal outcomes were extracted from routinely collected hospital records on the birth and postnatal period up until first hospital discharge.

The data from the first trimester interview and the third trimester questionnaire were linked to routinely collected hospital records which included: maternal age, marital status, socioeconomic group, nationality, public or privately funded antenatal care, parity, planned pregnancy, gestation at booking, BMI at booking, alcohol use, referral to a social worker. Maternal age was divided into the following bands: <20 years, 20–24 years, 25–29 years, 30–34 years, 35–39 years and ≥40 years. Socioeconomic groups were classified as professional, manager, employer, home duties, non-manual, manual, unemployed and non-classifiable. Two subgroups were formed for further analysis: higher socioeconomic group, including professionals and non-manual workers, and lower socioeconomic group, which comprised all other occupations. Nationality was initially recorded by region. This was further classified as Irish or non-Irish before analysis. Gestation at booking was banded as <12 weeks, 12–20 weeks and >20 weeks. Smokers were defined as women who were current smokers at the time of attendance at their first antenatal visit.

Women were asked about their folic acid use, if any. Recommended folic acid uptake for the prevention of first occurrence of NTD-affected births is defined as taking folic acid 400 mg each day, starting preconceptionally and continuing until the end of the first trimester (NICE, 2008). For the purpose of this study, folic acid use was defined as any, optimal (preconception and post-conception) and none.

Body mass index (BMI) was divided into four categories: <18 kg/m2, 18–24.9 kg/m2, 25–29.9 kg/m2 and ≥30 kg/m2. The information gathered on alcohol consumption during both phases was recorded in terms of units consumed. Participants were divided into three groups: never drinkers, ex-drinkers and current drinkers. Never drinkers included women who abstain from alcohol all of the time, ex-drinkers women who drink alcohol but abstain during pregnancy, and current drinkers women who were drinking at the time of completion of the recruitment and/or third trimester questionnaire. Information collected on smoking during both phases was divided into three groups: non-smokers, smoking abstention and current smokers. During the first interview, women were also asked whether they thought they had a healthy diet and whether they consumed five portions of fruit and vegetables per day. Exercise during pregnancy was categorised as never, once per week, <3 times per week and >3 times per week.

In addition, women were categorised as having a healthy or unhealthy lifestyle during the first trimester and third trimester of pregnancy. The healthy lifestyle group at both stages during pregnancy consisted of women who were non-smokers, non-drinkers, had a good diet and ate 5/day fruit and vegetables, took regular exercise such as walking, swimming, cycling, gym or running (>3 times/week) and had a BMI <30 kg/m2. The unhealthy group consisted of women who had any previously mentioned unhealthy characteristic.

Perinatal outcomes included gestational age at delivery, birth weight, infant's condition at birth including Apgar scores, admission to the neonatal unit, any suspected congenital abnormalities, and perinatal death. Preterm birth was defined as the birth of a live baby at less than 37 weeks' gestation and low birth weight was defined as weighing less than 2500 g.

Analysis

A total of 1915 women were invited to participate in the study, of whom 1300 completed the interview at the first hospital visit. Of these, 1216 women gave birth in the hospital and 907 (75%) completed the third trimester postal questionnaire. Birth and discharge data were available for 1216 women.

The analyses for this study were limited to the 907 mother–infant pairs on whom data were available from pregnancy through to birth. Data analysis was performed using the Statistical Package for Social Sciences (SPSS) version 21. Descriptive statistics were used to describe the study cohort at recruitment, in the third trimester and at birth (Dunney et al, 2015). Descriptive statistics were used to describe the cohort in relation to healthy or unhealthy lifestyle choices. Univariable logistic regression analyses were performed to report associations between healthy/unhealthy lifestyle choices and the sociodemographic characteristics of participants. Univariable logistic regression analyses were also performed to report the perinatal outcomes of infants born to healthy or unhealthy women. Findings are reported using proportions, odds ratios (OR) and 95% confidence intervals (CI).

Results

The characteristics of the cohort are presented in Table 1. The study cohort is mainly comparable to the general hospital population as found in a previous study on alcohol consumption during pregnancy (Mullally et al, 2011; Dunney et al, 2015). Exceptions were a higher proportion of non-Irish participants and a lower proportion of private patients. This reflects higher rates of recruitment in the public clinics. The loss of participants at follow-up was representative for each category.


Study population at recruitmentin=1300 (%) Study population at 3rd trimesteriin=907 (%) Study population at deliveryn=1216 (%) General hospital population¥n=6720 (%)
Maternal age at booking
<20 years 34 (2.6) 19 (2.1) 31 (2.5) 200 (3.0)
20–24 years 161 (12.4) 102 (11.2) 152 (12.5) 776 (11.6)
25–29 years 362 (27.8) 235 (25.9) 336 (27.6) 1527 (22.7)
30–34 years 453 (34.8) 334 (36.8) 427 (35.1) 2322 (34.6)
35–39 years 247 (19.0) 188 (20.7) 232 (19.1) 1592 (23.7)
≥40 years 43 (3.3) 29 (3.2) 38 (3.1) 301 (4.5)
Marital status
Married 679 (52.2) 505 (55.7) 635 (52.2) 3952 (58.5)
Single 621 (47.8) 402 (44.3) 581 (47.8) 2685 (40.0)
Socioeconomic group
Professional 341 (26.2) 258 (28.4) 317 (26.1) 2077 (30.9)
Home duties 222 (17.1) 135 (14.9) 206 (16.9) 961 (14.3)
Non-manual 491 (37.8) 369 (40.7) 481 (39.6) 2622 (39.0)
Manual 65 (5.0) 44 (4.9) 46 (3.8) 267 (4.0)
Unemployed 117 (9.0) 50 (5.5) 103 (8.5) 501 (7.5)
Non-classifiable 64 (4.9) 51 (5.6) 63 (5.2) 289 (4.3)
Nationality
Irish 888 (68.3) 618 (68.1) 839 (69.0) 5510 (82.0)
Non-Irish 412 (31.7) 289 (31.9) 377 (31.0) 1189 (17.7)
Gestation at booking*
<12 weeks 528 (40.8) 369 (40.7) 493 (40.5) 2666 (39.8)
12–20 weeks 729 (56.3) 523 (57.7) 687 (56.5) 3683 (55.0)
>20 weeks 37 (2.9) 15 (1.7) 36 (3.0) 349 (5.2)
Private health careŦ
Yes 145 (11.2) 122 (13.5) 142 (11.7) 1219 (18.1)
No 1155 (88.8) 785 (86.5) 1074 (88.3) 5499 (81.9)

Recruitment took place at participants' first antenatal visit to the hospital, which usually took place around 12 weeks' gestation

The third trimester questionnaire was completed by participants from 28 weeks of pregnancy

Study population at delivery includes intrauterine death (n=7) and neonatal death after delivery (n=1)

General hospital population February 2010–July 2011 with some missing data (Murphy et al, 2013a; 2013b; Dunney et al, 2015)

Missing data for gestation at booking n=6

Private health care includes semi-private and private care

The characteristics of the study cohort in relation to lifestyle behaviours during the first and third trimester of pregnancy are presented in Table 2. During the first trimester of pregnancy, 31.8% (n=288) of participants reported having an unplanned pregnancy. Only 28.1% (n=255) of women were taking the recommended amount of folic acid during that period, however a further 67.3% (n=610) of women reported taking some folic acid. During pregnancy, 44.1% (n=400) of women were considered overweight with a BMI ≥25 kg/m2. Despite the high proportion of women who were overweight, 85.7% (n=777) of women felt they had a healthy diet during the first trimester of pregnancy, with 65.7% (n=596) eating the recommended five portions of fruit and vegetables per day. During the third trimester, women became even more conscious of having a healthy diet, with 91.7% (n=830) of participants eating healthily. A high proportion of women did not exercise during pregnancy. However, the majority of women who did exercise did so more than three times a week: 35.7% (n=324) during the first trimester and 46.0% (n=417) during the third trimester. During the first trimester, 12.1% (n=110) of women consumed alcohol, and this increased to 29.2% (n=265) during the third trimester. Five women stopped smoking as their pregnancy continued to the third trimester.


1st trimester n=907 3rd trimester n=907
Unplanned pregnancy 288 (31.8)
Folic acid use
Any 610 (67.3)
Optimal 255 (28.1)
None 42 (4.6)
BMI at booking
<18 5 (0.6)
18–24.9 502 (55.3)
25–29.9 254 (28.0)
≥30 146 (16.1)
Alcohol
Never drinks 177 (19.5) 179 (19.7)
Previous drinker, now stopped 620 (68.4) 463 (51.0)
Current drinker (at booking and ongoing) 110 (12.1) 265 (29.2)
Smoking
Quit smoking 160 (17.6) 165 (18.2)
Current smoker (at booking and ongoing) 110 (12.1) 105 (11.7)
Diet
Healthy diet 777 (85.7) 830 (91.7)
5/day fruit and vegetables 596 (65.7) 649 (71.8)
Exercise*
Never 411 (45.3) 351 (38.7)
Once a week 39 (4.3) 66 (7.3)
<3 times a week 133 (14.7) 71 (7.8)
>3 times a week 324 (35.7) 417 (46.0)
* Missing data for exercise at 3rd trimester, hence figures do not total 907

When the study participants were classified as engaging in healthy or unhealthy lifestyle choices during pregnancy, over 80% of women were identified as having at least one unhealthy lifestyle behaviour throughout pregnancy. The characteristics of women who had a healthy lifestyle compared to an unhealthy lifestyle during the first trimester and the third trimester of pregnancy are presented in Table 3. Factors associated with a healthy lifestyle during the first trimester of pregnancy included women of Irish nationality, aged 35–39 years, and having private health care. Women having their first baby were more likely to engage in healthy behaviours during the third trimester. More than two thirds of women from the higher socioeconomic group were found to have factors contributing to an unhealthy lifestyle during the third trimester of pregnancy, while one third of unhealthy women had an unplanned pregnancy.


Study cohort total 1st trimester: Healthy lifestyle n=144 (15.9%) 1st trimester: Unhealthy lifestyle n=763 (84.1%) Odds ratio 95% Confidence interval 3rd trimester: Healthy lifestyle n=163 (18.0%) 3rd trimester: Unhealthy lifestyle n=744 (82.0%) Odds ratio 95% Confidence interval
Maternal age at booking
<20 years 2 (1.4) 17 (2.2) 0.83 (0.18–3.80) 2 (1.2) 17 (2.3) 0.55 (0.12–2.50)
20–24 years 14 (9.7) 88 (11.5) 1.13 (0.57–2.42) 20 (12.3) 82 (11.0) 1.15 (0.63–2.09)
25–29 years 29 (20.1) 206 (27.0) 1.00 41 (25.2) 194 (26.1) 1.00
30–34 years 59 (41.0) 275 (36.0) 1.52 (0.94–2.46) 70 (42.9) 264 (35.5) 1.25 (0.81–1.92)
35–39 years 37 (25.7) 151 (19.8) 1.74 (1.02–2.95)* 27 (16.6) 161 (21.6) 0.79 (0.46–1.34)
≥40 years 3 (2.1) 26 (3.4) 0.82 (0.23–2.88) 3 (1.8) 26 (3.5) 0.56 (0.15–1.89)
Gestation at booking
<12 weeks 64 (44.4) 305 (40.0) 1.36 (0.30–6.19) 63 (38.7) 306 (41.1) 2.88 (0.37–22.21)
12–20 weeks 78 (54.2) 445 (58.3) 1.13 (0.25–5.14) 99 (60.7) 424 (57.0) 3.26 (0.42–25.25)
>20 weeks 2 (1.4) 13 (1.7) 1.00 1 (0.6) 14 (1.9) 1.00
Nulliparous
73 (50.7) 346 (45.3) 1.23 (0.86–1.77) 93 (57.1) 326 (43.8) 1.70 (1.21–2.39)*
Married
84 (58.3) 421 (55.2) 1.13 (0.79–1.63) 97 (59.5) 408 (54.8) 1.21 (0.85–1.70)
Higher socioeconomic groupi
105 (72.9) 522 (68.4) 1.24 (0.83–1.85) 117 (71.8) 510 (68.5) 1.16 (0.80–1.69)
Irish nationality
111 (77.1) 507 (66.4) 1.69 (1.12–2.57)* 103 (63.2) 515 (69.2) 0.76 (0.53–1.08)
Private health care
29 (20.1) 93 (12.2) 1.81 (1.41–2.88)* 26 (16.0) 96 (12.9) 1.28 (0.80–2.05)
Unplanned pregnancy
43 (29.9) 245 (32.1) 0.90 (0.61–1.32) 44 (27.0) 244 (32.8) 0.75 (0.51–1.10)

Healthy categorised by: non-smoker, non-drinker, 5/day fruit and veg, exercises >3 times/week, BMI <30 kg/m2. Unhealthy categorised by: any of the previous lifestyle habits mentioned

Reference category

P<0.05

Higher socioeconomic group–professional and non-manual, versus all others

Of the 763 women who were found to have unfavourable lifestyle choices during the first trimester, 31% engaged in two and 15% in three or more unhealthy lifestyle behaviours. During the third trimester, 47% of women were found to have two or more factors contributing to an unhealthy pregnancy.

Perinatal outcomes associated with healthy lifestyle choices during pregnancy are presented in Table 4. In general, babies born to healthy mothers had better outcomes compared to those born to unhealthy mothers. A higher number of babies born to women with unhealthy lifestyle behaviours during pregnancy were preterm, weighing <2500 g and were admitted to the neonatal unit. Although not statistically significant, the incidence of adverse perinatal outcomes was almost doubled in women with unhealthy lifestyle behaviours.


1st trimester: Healthy lifestyle n=144 1st trimester: Unhealthy lifestyle n=763 Odds ratio 95% Confidence interval 3rd trimester: Healthy lifestyle n=163 3rd trimester: Unhealthy lifestyle n=744 Odds ratio 95% Confidence interval
Preterm birth < 37 weeks 3 (2.1) 40 (5.3) 0.38 (0.17–1.25) 5 (3.1) 38 (5.2) 0.58 (0.22–1.52)
Low birth weight < 2500 g 3 (2.1) 30 (4.0) 0.51 (0.15–1.71) 4 (2.5) 29 (3.9) 0.62 (0.21–1.79)
Apgar score < 7 at 5 minutes 1 (1.7) 12 (1.6) 0.44 (0.05–3.41) 4 (2.5) 9 (1.2) 2.06 (0.62–6.79)
Admitted to neonatal unit 18 (12.6) 114 (15.1) 0.80 (0.47–1.37) 25 (15.5) 107 (14.6) 1.07 (0.67–1.73)
Congenital abnormality (any) 2 (1.4) 19 (2.5) 0.54 (0.12–2.38) 3 (1.9) 18 (2.4) 0.75 (0.22–2.60)
Perinatal death 0 3 (0.4) 1 (0.6) 2 (0.3) 2.29 (0.20–25.4)

Discussion

Pregnancy is a time in a woman's life when she may develop a greater appreciation of her own health along with the health of her developing baby. Current advice to women in Ireland who are planning a pregnancy or who are already pregnant is to avoid consuming alcohol and not to smoke. Women are encouraged to eat a healthy balanced diet, which incorporates a periconceptional daily supplement of folic acid. All women are also encouraged to begin or continue light to moderate exercise. This study was designed to investigate women's reported health behaviours during pregnancy. Sociodemographic characteristics of women who were deemed ‘healthy’ or ‘unhealthy’ during pregnancy were identified, which established ‘at risk’ groups of women. Adverse perinatal outcomes were identified and compared for the ‘healthy’ and ‘unhealthy’ women during pregnancy.

The study cohort was representative of women attending a large maternity hospital between 2010 and 2011 (Mullally et al, 2011; Dunney et al, 2015). Unfortunately, we found that few women overall comply with all lifestyle recommendations for pregnancy. This study reports that during the first and third trimester of pregnancy, more than 80% of women were classified as having an unhealthy pregnancy based on at least one unfavourable factor.

Maternal smoking during pregnancy is a worldwide issue with varying rates. This study found that 16% of women smoked during the first trimester of pregnancy; however, this decreased to 12% as pregnancy continued. Previous Irish studies have reported maternal smoking rates during pregnancy between 20% to 29%, so this indicates some improvement from previous reports (Donnelly at al, 2008; Tarrant et al, 2011).

Advice on alcohol consumption during pregnancy varies in different countries. However, current advice to women in Ireland is that when planning a pregnancy or during pregnancy, alcohol should be avoided at all times. This study found that 12% of women reported consuming alcohol during the first trimester but this increased to 29% during the third trimester of pregnancy. This increase in the proportion of women resuming alcohol consumption later in their pregnancy may be a result of women considering the first trimester to be the most important time for fetal development. However, compared to a previous Irish study that reported alcohol consumption during the third trimester at a rate of 35.3% (Tarrant et al, 2011), the rate in this study was slightly lower. This decrease may be a result of recent media campaigns in Ireland to increase awareness of the harmful side effects of consuming alcohol during pregnancy (Dunney et al, 2015).

In this study, 66% of women reported taking some folic acid before and during pregnancy. Only 25% of women complied with optimal folic acid supplementation recommendations of 400 mcg daily. Generally, folic acid supplementation is reported as being low, and this study found similar rates as previous Irish studies (Ward et al, 2004; McGuire et al, 2010). The findings of this study suggest that three quarters of the population did not receive optimal protection and are at risk of having a baby born with an NTD. This is discouraging as it implies that messages about folic acid supplementation and prevention of NTDs are not reaching all women of childbearing age. Further public health campaigns are required to raise awareness of the optimal time frame and dosage of folic acid to prevent NTDs.

Maternal nutrition at conception and during pregnancy influences the development of the fetus. Previously, a commonly accepted thought was that the developing fetus was nourished adequately at the expense of maternal stores (HSE, 2013); however, it is becoming clear that development of the baby can be less than optimal if certain nutrients are not available during pregnancy (HSE, 2013). A pregnant woman's diet should be based on the national food pyramid, with added nutrient supplementation when advised. In this study, 83% of women reported that they had a healthy diet, with 63% of them consuming five portions of fruit and vegetables per day during the first trimester. These figures increased to 92% having a healthy diet and 72% eating the recommended daily serving of fruit and vegetables during the third trimester of pregnancy. These findings are encouraging as there appears to be an increase in healthy eating compared to a previous Irish report, which found that less than 50% of women during pregnancy met the recommendations for each group of the food pyramid (O'Neill et al, 2011). The findings of this study are evidence that public health education initiatives on healthy eating can have a positive impact; however, continuous reinforcement of health-enhancing awareness is required.

Although the majority of women thought that they had a healthy diet, over a third of women during both stages of pregnancy observed in this study were overweight as calculated by their BMI. Maternal obesity during pregnancy is linked to a number of adverse outcomes for both the mother and baby. Obesity in pregnancy has been identified as an increased risk of complications including gestational diabetes mellitus, pre-eclampsia and venous thromboembolism. Obesity can also result in higher incidence of obstetric interventions such as caesarean section births, as well as haemorrhage and infection (O'Dwyer and Turner, 2012). Weight can be a sensitive subject and it is important that information about obesity and its risks is communicated in an informative, understanding manner. Women who are underweight, overweight or obese should be seen for pre-pregnancy dietary counselling, ideally in the community, to optimise weight prior to conception and therefore reduce associated risks during pregnancy (HSE, 2013).

Another major lifestyle behaviour in pregnancy is exercise. The introduction of recommendations for physical activity during pregnancy is relatively new, and both the American College of Obstetricians and Gynecologists (ACOG) and the UK's Royal College of Obstetricians and Gynaecologists (RCOG) recommend 30 minutes of daily moderate-intensity physical activity for women who are pregnant (ACOG, 2002; RCOG, 2006). In Ireland, a previous study reported that the majority of women (76%) do not reach the recommended levels of exercise during pregnancy (Walsh et al, 2011). This study found that more women are now exercising during pregnancy, with 35% (in the first trimester) and 46% (in the third trimester) exercising more than three times a week. However, disappointingly, there are still a lot of women who do not carry out any exercise. Almost half of the women in this study never exercised during the first trimester of pregnancy. Regular exercise is promoted for its overall health benefits for mother and baby. Pregnant women should be informed that beginning or continuing a moderate course of exercise during pregnancy is not associated with adverse outcomes to the mother or the baby (NICE, 2008). All health professionals should be educated regarding the benefits of physical activity in pregnancy and should be encouraged to pass on these messages to women.

It is apparent from the findings of this study that women do not always follow healthy lifestyle behaviour recommendations before and during pregnancy. Clustering of factors contributing to an unhealthy lifestyle during pregnancy is also evident. Up to 47% of women who engaged in unhealthy lifestyle choices were found to be engaging in not only one, but two or more unhealthy behaviours during the first and third trimester of pregnancy. This study suggests that a large number of women do not comply with lifestyle behaviour recommendations during pregnancy and are, therefore, putting both themselves and their unborn babies at increased risk of preterm delivery, low birth weight and being admitted to the neonatal unit. Interestingly, there were three perinatal deaths recorded for women who were unhealthy in the first trimester, compared to none in the healthy group. Although no statistically significant findings were established, the incidence of adverse perinatal outcomes was almost doubled in women with unhealthy lifestyle behaviours.

‘Encouraging women to engage in healthy lifestyle behaviours prior to and during pregnancy could reduce the risk to the developing baby and lessen the number of adverse perinatal outcomes’

Strengths and limitations

This study consisted of a representative cohort of women attending maternity care in a large urban hospital over a 2-year period. The data were collected prospectively by qualified health researchers during the first and third trimesters of pregnancy. A standardised interview schedule was used to collect data during the first trimester and a self-completed questionnaire was used for data collection during the third trimester. Data collection was supplemented by routinely collected hospital records. Therefore, the research team had detailed information on women's lifestyle behaviours during pregnancy and pregnancy outcomes.

As data were collected from participants at two separate time points, the potential for recall bias was limited. However, the data on the lifestyle behaviours that the researchers reviewed—smoking, alcohol consumption, diet, exercise and folic acid supplementation—relied on self-reporting by the pregnant women, and it is possible that under-reporting may have occurred. Despite written reminders and follow-up phone calls, there was a loss of responders in the third trimester; however, the profile of the cohort at the first trimester and during the third trimester suggests that the loss at follow-up was random rather than specific to a particular group of women. As it was not feasible to approach all women booking for antenatal care at the hospital during the period of the study, it is possible that the behaviours and outcomes of those who were not approached or declined to participate differed from those who did take part. Nonetheless, we are satisfied that a broad spectrum of women was sampled.

Implications for practice

This study found that few pregnant women follow all of the healthy lifestyle behaviour recommendations that we reviewed. Encouraging health behaviour changes were found in some areas of women's lifestyle habits compared to previous research; however, women are still not following all current health recommendations during pregnancy, with many choosing to continue several unhealthy behaviours. Overall, as pregnancy continued, women reduced their consumption of cigarettes, increased their time spent exercising and followed a healthier diet. However, despite current government recommendations in Ireland to abstain from alcohol when pregnant, more women resumed alcohol consumption as pregnancy progressed. Clearly, some women did not want to follow this health recommendation.

It is essential that health professionals gain knowledge into specific predicting factors associated with unhealthy lifestyle choices. With this information, health professionals can understand more about women who need to change their behaviours. The findings of this study suggest that there is an ongoing challenge for midwives and other health professionals to continue to address the issues of lifestyle behaviours, specifically diet, folic acid, exercise, smoking and alcohol, for women who are planning a pregnancy and/or throughout pregnancy. Encouraging women to engage in healthy lifestyle behaviours prior to and during pregnancy could reduce the risk to the developing baby and lessen the number of adverse perinatal outcomes. This, in turn, would have positive implications for affected families and the Irish health-care system. Public health campaigns need to continue to educate and change attitudes towards healthy lifestyle choice during pregnancy. Leaflets, poster campaigns, television adverts and the internet can be used for multi-component health education strategies. Midwives are often the first point of contact for newly pregnant women and are a key source of support and information. Education from midwives can take place at any maternity visit. Midwives need to continue to use these opportunities to encourage compliance with healthy lifestyle choices and reinforce these messages during the third trimester.

Conclusion

This study shows that few pregnant women followed all of the lifestyle recommendations that we reviewed. When women were classified as having healthy or unhealthy lifestyles during pregnancy, over 80% of women were considered to engage in unhealthy lifestyle behaviours with clustering of behaviours evident. This study emphasises the need for improved identification of women who are at risk and for early intervention. The ongoing challenge for health professionals is to provide effective strategies to support women to have a healthy lifestyle. Health professionals working with pregnant women have a unique opportunity to influence the lifelong health of the mother, infant and the family unit, by encouraging appropriate healthy lifestyle choices.

Key points

  • Women attempting to conceive and those in early pregnancy are advised to alter their lifestyles to achieve and maintain a healthy pregnancy
  • This study was designed to investigate women's reported health behaviours (diet, exercise, alcohol, smoking, and folic acid use) during pregnancy and to identify ‘at risk’ groups of women and their pregnancy outcomes
  • Over 80% of women were found to have factors contributing to an unhealthy lifestyle during the first and third trimesters of pregnancy, with clustering of unfavourable lifestyle choices evident
  • The findings of this study suggest that there is an ongoing challenge for midwives and other health professionals to continue to address the issue of lifestyle behaviours for women who are planning a pregnancy or are already pregnant
  • Encouraging women to engage in healthy lifestyle behaviours before and during pregnancy could reduce risk to the developing fetus and lessen the number of adverse perinatal outcomes which, in turn, may have positive implications for both affected families and the Irish health-care system