Fascinating Danish study: fake sugar is associated with permature births.  I’ve been an advocate for real sugar (in serious moderation) for years, but there has been a lack of damning evidence in humans.  Interestingly, there is a nice dose-response relationship (more fake sugar, higher the likelihood of an early birth).  Epidimiological studies like this one do merely set the stage for stronger double blinded randomized trials.  Unfortunately, randomizing pregnant women is generally considered to be unethical– because it IS when you know one choice is damaging– so this will have to be further explored through prospective and retrospective studies. 

Meanwhile, the study found that the risk is slight, but worth trying to avoid if you can.  Smaller doses (1-3 diet sodas/day) raise the risk by about one-third and high doses (greater than 4 diet sodas/day) raise the risk by about 75%.  Translation: if there are 40 preterm births in a group of 1000 women who drink no diet sodas, the same group of women who drank lots of diet soda would have about 70 pre-term births.  One caveat, though, the question of whether different sweeteners have different effects was not examined.

Add it to your list, ladies.  No pretty colored packets during pregnancy.  Instead, stick to the boring white and brown packets and small amounts of regular (non-diet) sodas or seltzer.

Citation: Am J Clin Nutr. 2010;92:626-633
Abstract: http://www.ncbi.nlm.nih.gov/pubmed/20592133?dopt=Abstract