Health Promotion and Lifestyle Change During Pregnancy -Healthy policy on maternal nutrition, smoking, alcohol consumption and pregnancy outcome
Many expectant parents are at one extreme or another when it comes to their lifestyle during pregnancy. They break habits and take up new habits, all in an attempt to bring a healthy baby into the world. In reality, most have an unclear idea of the role various lifestyle choices play during pregnancy. Will the cheeseburger I ate make my baby have health issues? If I drink alcohol, will my baby have development issues? It is a web of questions that seem to have a whole host of opinionated answers. But what does research say? For the best result possible, it is vital to understand the studied outcome of the choices we make while pregnant.
A growing body of evidence indicates that the pre-natal period is a sensitive period for later health outcomes and prenatal priming is a term increasingly used to describe the long-term effects on health outcomes programmed by pre-natal and early post-natal factors. Lifestyle changes are important to the health of the fetus during pregnancy, and in early parenthood to create a health-promoting environment for the child.
Healthy policy on maternal nutrition
How important is maternal nutrition in determining the outcome of pregnancy? “Very important,” most people, prenatal care providers and public health policy-makers would reply. But a careful examination of the available evidence does not strongly support such an answer.
What evidence is available from studies of actual nutritional intake among pregnant women? The extreme reduction in energy intake imposed by the Germans on the Dutch during the so-called “hunger winter” of 1944/45 led to large reductions in birth weight among the babies of women affected during the third trimester of pregnancy, but there was no perceptible impact on gestation duration or other pregnancy outcomes. Controlled clinical trials of balanced energy–protein supplementation during pregnancy have shown only modest effects on gestational weight gain and fetal growth and few, if any, benefits for other pregnancy outcomes. A recent trial from Gambia indicated that the effect on fetal growth may be greater in extremely malnourished mothers, but maternal malnutrition to this extent probably does not exist in developed countries.
Many nutritionists, prenatal care providers and public policy-makers would counter that it is the quality of the diet, not its quantity, that is most important. Thus, it is argued, pregnant women who eat calorically dense “junk food” may gain adequate (or even excessive) amounts of weight during pregnancy but are nevertheless at nutritional risk for adverse pregnancy outcomes.
Secular (temporal) increases in pre-pregnancy body mass index and gestational weight gain (along with a reduction in maternal smoking) are probably responsible for the increase in mean birth weight and the modest decline in low birth-weight rates observed over the last quarter century.
On another side, pre-pregnancy obesity is strongly associated with late fetal death (stillbirth) and excessive weight gain increases the risk of fetal macrosomia (also known as big baby syndrome), cesarean section and maternal weight retention (difficulty losing pregnancy weight).
A recent UK prospective study analyzed the relationship between gestational weight gain (GWG) and pre-pregnancy weight with the delivery of overweight babies and resulting cardiovascular risk factors.
Data was collected from 5,154 (for adiposity and blood pressure) and 3,457 (for blood assays) mother-offspring pairs. The study showed that women who exceeded the 2009 Institute of Medicine–recommended GWG were more likely to deliver babies with greater body mass index, waist, fat mass, leptin, systolic blood pressure, C-reactive protein, and interleukin-6 levels and lower high-density lipoprotein cholesterol and apolipoprotein A1 levels.
When examined in more detail, there was a definite link between pre-pregnancy weight and offspring adiposity (increased birth weight). It also showed that by the age of 9, these children are at greater cardiovascular risk. Although GWG in early pregnancy (0 to 14 weeks) was positively associated with offspring adiposity across the entire distribution, it was reinforced when looking at women gaining more than 500 g per week. Interestingly, GWG between 14 and 36 weeks was positively and linearly associated with adverse lipid and inflammatory profiles. The conclusion of the study was that the greater maternal pre-pregnancy weight and GWG up to 36 weeks of gestation can result in greater offspring adiposity and adverse cardiovascular risk factors.
Maternal pre-pregnancy weight was more consistently associated with higher birth weight and a wider range of cardiovascular risk factors in offspring than were any measurement of GWG. This finding supports the emphasis placed on women (of reproductive age) maintaining a healthy weight.
Alcohol consumption in pregnancy as a risk factor for later mental health problems
Many expectant parents are increasingly interested in the possible mental health risks for their children as a result of drinking alcohol while pregnant. A controversial question has been asked about whether there is a safe amount of alcohol that can be consumed during pregnancy and whether international policy recommendations are based on evidence.
There are currently considerable international differences in policy recommendations about alcohol use in pregnancy. Some countries such as the USA, Canada and France recommend complete abstinence. This recommendation appears to be based on a precautionary approach, given that no clear research suggesting otherwise has been established. In contrast, until May 2007, guidelines in the UK were that pregnant women could safely drink one or two drinks per occasion up to 1–2 times per week (that is, up to a total of four alcoholic drinks per week). This approach seems to be based on the lack of available evidence about the relationship of alcohol consumption and adverse outcomes. However, these recommendations were recently revised to advocate refraining from drinking during pregnancy.
The National Perinatal Epidemiology Unit focused a recent review on literature concerning risks associated with low to moderate levels of alcohol consumption during pregnancy. More conclusive evidence suggests that a higher level of drinking, manifesting at the extreme end as fetal alcohol syndrome. In the USA, the occurrence of fetal alcohol spectrum disorder (FASD) has been estimated at around 1% of live births. In Europe, rates of FASD have been estimated at 2–4%. The majority of these children are described as having an alcohol-related neuro-developmental disorder, with visible problems with over activity, inattention, and behavior or learning difficulties. Outcomes such as these are associated with moderate alcohol consumption (for example, an average of one drink per day). These findings have been replicated in animal studies, suggesting there are critical vulnerable periods for neurodevelopment.
Other studies have shown that even low levels of drinking during pregnancy may affect a child’s mental health. A study in the USA indicated that up to 3–4 drinks per week was directly linked to behavioral problems in children between 6 to 7 years old. Recently, the UK extended the findings. It was found that less than one drink per week in the first trimester could result in higher levels of mental health problems when the child is between 4–8 years.
In summary, when debating whether or not to have a drink, remember that even moderate drinking (1–2 drinks per day) of alcohol during pregnancy could result in childhood attention and behavioral problems. Evidence has shown that the risks from alcohol consumption in pregnancy may persist over time. Cohort studies also suggest ongoing learning problems, behavioral difficulties, and adult psychiatric disorders such as personality and substance use disorders in adolescence and early adulthood.
Smoking during pregnancy: maternal characteristics, and pregnancy outcomes
Have you debated quitting smoking? This decision is one of the most important actions an expectant mother can take to improve the outcome of her pregnancy. Women know how smoking can affect their health and that of their unborn children. Because of this, pregnancy may be the perfect time to successfully quit smoking. Nevertheless, most smokers do not stop smoking during pregnancy. Two-thirds of women who smoke during their first pregnancy also smoke during their second, exposing their infant to tobacco smoke both in utero and after delivery.
Many countries consider smoking during pregnancy as the most important preventable risk factor for an unsuccessful pregnancy outcome. Smoking is causally associated with fetal growth restriction, and increasing evidence also suggests that smoking may cause stillbirth, preterm birth, placental abruption, and possibly sudden infant death syndrome. Smoking during pregnancy is generally associated with increased risk of spontaneous abortion, ectopic pregnancies, and placenta previa. It may also increase risks of behavioral disorders in childhood.
There is a direct link between the exposure to smoke and the diagnosis of childhood attention deficit hyperactivity disorder (ADHD). Although findings are not clear, the association between the two has been demonstrated across various samples controlling for potentially confounding effects. They analyzed a dose-dependent relation, and results indicated that risk increases with the quantity of cigarettes smoked. It has also been proposed that the fetus could be affected by smoking through biologically plausible pathways. Is it possible that smoking during pregnancy could play a role in infant/childhood obesity? A recent systematic review and meta-analysis showed that if a mother smokes during pregnancy there are increased odds that her child will be overweight.
Publications from the Avon Longitudinal Study of Parents and Children (ALSPAC) have
demonstrated that if an expectant mom smokes, there is an increased likelihood that her child will be shorter than average at 7 ½ years old and have issues with weight to height proportions (from 7 to 10 years old). According to the study, children who have been exposed to smoking had more severe behavioral problems with greater externalizing symptoms and more conduct and oppositional defiant disorder items, lower verbal IQ, and a sluggish cognitive profile on the Continuous Performance Test (CPT). Linear regression analysis revealed a relationship between the average number of cigarettes smoked per day during pregnancy and verbal IQ, CPT omission errors T score and several other clinical variables. Animal models demonstrate alterations in brain structure and function following prenatal nicotine exposure.
So, when contemplating whether or not to quit smoking, studies have shown that maternal smoking before or in pregnancy could result in risk of obesity in 5- or 6-year old children. In addition, maternal smoking during pregnancy is associated with long-term neurobehavioral and cognitive deficits in children.
Educating yourselves on the outcomes of your choices is the most important step expectant parents can make. By understanding the research behind your doctor’s suggestions, you become better equipped to handle the ups and downs of pregnancy. Research suggests that expectant parents should refrain from alcohol and smoking and take advantage of proper nutrition. These small steps can help produce a healthy child and will decrease your child’s risk of cardiovascular disease, obesity, as well as various other behavioral and neurological issues.