3. QUESTIONNAIRE DATA: ANALYSIS OF DATA OF THE STUDY
3.3. Discussion
In this study we have used an extensive range of questions to obtain as much information as possible about the cohort of the patients we dealt with. In this chapter main emphasis was on exercise and nutrition of these pregnant women before and during pregnancy. It should be noted that maternal attitudes and foetal outcome is discussed in length in Chapter 6 of the thesis. A key finding of our study is that there was a significant reduction in the intake of alcohol, caffeine-containing and sugary drinks as well as sugary refreshments during pregnancy. Moreover, in our cohort 14% of women smoked during pregnancy. This is comparable to a recent study of Australian women that showed 14.8% of nonindegenous women smoking during pregnancy (Mendelsohn, 2010). Maternal smoking during pregnancy is a well established risk factor for perinatal mortality, miscarriage, and premature births (Hackshaw et al., 2011). Nicotine and carbon monoxide can cross the foeto-placental barrier and reach high concentrations in the foetus, reducing placental blood flow leading to foetal hypoxia and subsequently growth restriction (Einarson, 2009). Nicotine is a neurotoxin to the developing brain and causes cognitive, emotional and behavioural problems. Children born to mothers who smoke in pregnancy also have reduced lung function and an increased risk of respiratory illness. Exposure to heavy smoking in utero also increases the risk of nicotine dependence in adulthood (Mendelsohn, 2010). In this study another interesting finding was unearthed, since parental/passive smoking was not reduced in the household during pregnancy, staying at a high rate of 59%. This could be detrimental, as all types of passive smoking have been associated with a significant increase in the risk of infants developing lower respiratory infections in the first two years of life (Jones et al., 2011).
In this questionnaire also incorporated seven questions relating to the immune profile of this cohort. We have done so, as acute infections in pregnant women are often associated with adverse effects such as miscarriage, pre-term labour or even stillbirth (Goldenberg et al.,
2010; 2000). There is also evidence from epidemiological data that infections during pregnancy might precipitate other pathologies like preeclampsia (Conde-Agudelo et al., 2008). Data from this self-reported questionnaire indicated that the vast majority of participants do not suffer from allergies, do not have an inflammatory disease or are prone to cystitis. The most common infection reported was a cold and 36.5% of pregnant women found it hard to shift the upper respiratory infection. Interestingly, a significant inverse correlation has been noted between difficulty to shed an infection and number of colds and number of infections during pregnancy. Similar data has been obtained by a very recent study of Australian women, where cold was the commonest infection reported using a similar self-reported method (Lain et al., 2011). Our study has a number of limitations, with reliance being one. In the study by Lain et al., only 21% of the women that reported an infection sought medical attention. We do not have such records for our cohort. Moreover, given that we have asked the patients to self-report at the end of the third trimester there might be issues with recall bias. We would like to acknowledge powerful conclusion from an earlier study using an analogous type of reporting. The authors concluded that “future studies should emphasise the importance of interviewing women as early as possible, as mothers tend to under-report infection” (Collier et al., 2009). However our data related to the immune profile also has certain strengths as it includes the investigation of numerous rather a single infection and incorporated both chronic and acute infections. These data can be of clinical importance as gynaecologists can use a self-reported method for infections to classify patients in a high or low group for predisposition towards pregnancy complications such as preeclampsia. With regards to caffeine effects during pregnancy, there is still some controversy in the field.
Caffeine is readily absorbed from the mucosa of the gastrointestinal tract. It crosses the human placenta rapidly reaching concentration in the foetus similar to maternal plasma levels. Caffeine has been implicated as a cause of spontaneous abortion, intrauterine growth
restriction (IUGR), low birth weight (LBW) and pre-term delivery (Kuczkowski, 2009).
However, other investigators failed to find any association between caffeine intake and poor pregnancy outcomes (Wen et al., 2001), whereas some studies have shown positive outcomes. Adeney et al., have shown that moderate caffeine consumption during pregnancy exerts a protective effect towards gestational diabetes mellitus (GDM) (Adeney et al., 2007).
These mixed results may arise due to the problem of accurately assessing the caffeine intake.
Moreover the amount of caffeine varies tremendously in different coffee chains. In a very recent study, analysis of 20 commercial espresso coffees using high performance liquid chromatography (HPLC) technology revealed differences in caffeine levels up to 6-fold (Crozier et al., 2011). The authors of this study concluded that single serving of high caffeine espresso could well place at risk individuals who are more susceptible to the effects of caffeine toxicity, including women who are pregnant. In our cohort, a significant reduction in caffeine intake has been noted however we were not able to quantify the precise amount ingested. Nawrot and colleagues have suggested that women of reproductive-aged should consume less than 300 mg of caffeine/ day (equivalent to 4.6 mg/kg body weight per day for a 65-kg person; Nawrot et al., 2003). Another key finding was the significant decrease of sugar-containing drinks during pregnancy. In USA for example, sugar-sweetened soft drinks are the principal energy contributor in the diet (Block, 2004) and they appear to play a role in the obesity epidemic due to their high content of readily absorbed sugars (Schulze et al., 2004). In a recent study involving 59.334 Danish pregnant women it has been shown that daily intake of artificially sweetened soft drinks may increase the risk of pre-term delivery (Halldorson et al., 2010). It appears therefore that the decreased noted in this study might indeed protect from preterm labour. Clearly further epidemiological studies are needed to confirm these effects.
Of interest, a wide range of responses related to the consumption of fried/fast-food during pregnancy were given. As mentioned previously, poor nutrition can lead to a range of health problems for mothers, including metabolic syndrome and cancer. Pregnancy results in a state of increased energy demands of ~300 kcals/day. Moreover maternal energy metabolism is altered during pregnancy and varies greatly among women. The same women that had increased consumption of fast food had also increased intake of iron-rich and dairy products.
However, there is no evidence to suggest that these beneficial intakes of calcium and iron counteract poor eating habits. Our findings are comparable to an Australian study of 409 women where a substantial proportion of pregnant women consumed 2 meals of snacks (fast food/take away) per week (Wen et al., 2010). This finding might also reflect that young generations seem to deviate from the traditional Mediterranean dietary pattern, adopting new dietary trends (Baldini et al., 2009). Moreover, dietary patterns can be influenced by various socio-demographic characteristics. Taking these into consideration it is imperative to develop dietary interventions to prevent undesirable health consequences during pregnancy. Another factor that can affect pregnancy is exercise. Regular physical activity is associated with improved physiological, metabolic and psychological parameters, and with reduced risk of morbidity and mortality (Melzer et al., 2010). In our study (based on the Paffenbarger et al.
1978) there was a clear shift towards a sedentary lifestyle during pregnancy. For example, there was an increase in overall inactivity of approximately 15% and an equal decrease of moderate exercise. Regular physical activity during pregnancy has been proven to be beneficial for the mother as well as the foetus. Maternal benefits include: better cardiovascular function, small weight gain during pregnancy, decreased musculoskeletal discomfort, and mood stability, reduction of GDM and gestational hypertension that can lead to preeclampsia (PE). Benefits for the foetus include: reduction of fat mass, coping better with stress, and advanced neurobehavioural maturation (Melzer et al., 2010). The adoption or
continuation of a sedentary lifestyle during pregnancy may contribute to the development of certain disorders such as hypertension, maternal and childhood obesity, GDM, dyspnoea, and PE (Melzer et al., 2010). In view of the global epidemic of sedentary life-style and obesity, we propose that pregnant women should increase their physical activity as prevention of adverse pathologies for the mother as well as the foetus. Further studies with larger sample sizes are needed to provide solid evidence of associations between increased physical activity and positive outcomes of labour and delivery.