Is there ever really a perfect time to start a family? If you're in the planning stage or wanting to grow your family you might want to rule out the month of May for conception.
Why May you ask? According to a recent study, children conceived in the month of May have a 10% higher risk of being born premature.
The study authors believe that may be a function of the expectant mother's increased exposure to the seasonal flu during January and February, exactly when a baby conceived in May is nearing term.
"We were surprised that the relationship between potential flu exposure and premature birth appears to be so evident in the data," said study author Janet Currie, director of the Center for Health and Wellbeing at the Woodrow Wilson School at Princeton University. "There has been some recent work suggesting that flu can induce premature labor in women late in pregnancy, and our results appear to corroborate this."
Currie also added that if mothers-to-be received a flu shot they might not be at risk for premature labor due to flu infection. While the study did provide an association between conception in the month of May and premature births, it did not prove a direct cause-and-effect.
To explore the potential impact of conception timing on infant health, the researchers analyzed data on roughly 647,000 mothers in the northeastern region of the United States. All the women had given birth to more than one child.
In addition to dates of birth and lengths of pregnancies, the data included information on maternal weight changes, race, education and smoking history.
The research team noted that by looking solely at the conception-to-birth experience of more than 1.4 million siblings (as opposed to non-related babies), they were able to compare apples to apples, and sidestep other complicating factors that might influence prematurity risk, such as a family's wealth or educational background.
The result: The authors identified a "sharp trough" in the length of pregnancies that began in May.
In addition to reviewing month-by-month conception records, researchers studied post-1997 influenza data from the U.S. Centers for Disease Control and Prevention and found a correlation between May conceptions and a significant increase in flu exposure during the third trimester of those pregnancies.
If you're thinking about conceiving in the summer months, the research team found that those babies tended to weigh little bit more at birth than babies conceived at other times of the year. In the world of newborn babies, even an ounce can make a positive difference in health.
"The birth weight results suggest that infants conceived during the summer have higher birth weight in part because mothers tend to gain more weight during pregnancy when they conceive in summer," Currie said. "It seems likely that this is because they have a better diet, though we cannot directly observe that in our data.
"We cannot rule out other factors that might also be important for pregnancy outcomes," she said. "But we think the message of our paper is that parents should take steps to guard against known problems," suggesting that the most practical thing pregnant women can do is simply eat well and get a seasonal flu shot. "That would probably be a more sensible approach then trying to time conception to avoid May."
Too many mothers-to-be avoid getting flu shots because they fear that the vaccine my cause their baby harm. Studies have shown that the vaccine is perfectly safe for pregnant women.
The take away from this study appears to be that if you're planning on getting pregnant make sure that you are protected from influenza infection by getting the flu vaccine. If possible, you might want to avoid conceiving in the month of May, and if you want a little bigger baby- try for the summer months.
Source: Alan Mozes, http://www.webmd.com/baby/news/20130708/month-of-conception-might-raise-odds-of-premature-birth-study?print=true