Study under review: Omega‐3 fatty acid addition during pregnancy
Pregnancies are difficult and risky in general, but complications can be devastating and fatal. For example, preterm birth, which is defined as an infant born before 37 weeks of gestation, accounts for more than 85% of perinatal complications and deaths in newborns. It is also the leading cause of death in children under the age of five, accounting for nearly 17% of all child deaths.
Although advances in neonatal care have reduced mortality rates, children who are born preterm also experience developmental issues and are also at higher risk for several conditions such as respiratory distress syndrome, necrotising enterocolitis, blindness, and cerebral palsy.
Adding to the possibility of such complications during pregnancy is the risk of depression, the most common mood disorder correlated with childbirth. A 2005 systematic review suggests that nearly 20% of women experience depression within three months of giving birth. Postnatal depression is also associated with poor childhood development outcomes.
Interventions that can reduce such complications are highly sought after. Prior research has shown that omega-3 fatty acids hold much promise. In the late 1980s and into the 1990s, health researchers noticed that certain populations who consumed diets high in fish had better pregnancy outcomes. However, many of these studies were observational and may have suffered from selection bias and confounding. While there are complex statistical and graphical methods to help address these problems, it is still difficult to conclude a causal relationship from such data, so randomized controlled trials (RCTs) were necessary to investigate the link.
As you can see in Figure 1’s timeline, a Cochrane review of six RCTs from 2006 concluded that there still was not enough evidence to recommend omega-3 fatty acid supplementation for pregnancy outcomes. Six years later, a systematic review of 15 RCTs found a small benefit on preterm birth. However, a 2015 systematic review of nine RCTs failed to find a significant difference, along with a 2016 systematic review of 95 RCTs and 48 observational studies by the U.S. Agency for Healthcare Research and Quality.
The study under review sought to review all of the current published and unpublished clinical trials, update the 2006 Cochrane analysis, and determine the effects of omega-3 interventions on preterm birth and several other pregnancy outcomes.
Preterm birth along with other pregnancy complications are responsible for a notable proportion of child deaths. Early observational research showed that populations that consumed fish also had better pregnancy outcomes. However, systematic reviews of randomized trials in the past decade failed to show any statistically significant effects on outcomes like preterm birth. The study under review looked at all the published and unpublished studies to date to assess the overall effect of fish oil on various pregnancy outcomes including preterm birth.
Other Articles in Issue #51 (January 2019)
Vitamin K for vascular health
How does vitamin K supplementation impact vascular calcification and stiffness? And does observational evidence suggest an association between vitamin K status and cardiovascular disease and death?
Mini: Do longer term, large doses of vitamin D have any adverse effects?
As more people take vitamin D, doses can creep up, whether from daily supplementation or large, periodic bolus doses. This meta-analysis examined whether larger doses of vitamin D over longer periods of time have any adverse effects.
Investigating intermittent fasting for body composition and overall health
Intermittent fasting seems like a solid way to improve metabolic health outcomes like insulin sensitivity. But are these improvements accounted for by just the weight loss and caloric restriction alone?
Mini: Personalized weight loss diets for people with prediabetes
This secondary analysis of a clinical trial suggests that macros may matter when it comes to shedding pounds for people with prediabetes.
Investigating curcumin for weight loss
This meta-analysis found that curcumin supplementation can lead to small amounts of weight loss.
Magnesium intake modulates vitamin D status
Nutrients can often interact in our bodies in complex ways. This study found that magnesium intake influences vitamin D levels in complex ways that depend on baseline vitamin D status.
Is it all just fishful thinking?
We give the lowdown on the important VITAL trial, a large, long-term clinical study that examined vitamin D's and fish oil's effects on cancer and cardiovascular disease.