As strong as those coffee cravings are, many women who are pregnant or trying to become pregnant already know the advice to seriously limit their Starbucks runs. Now researchers are reporting that it's not just your caffeine intake, but also your partner's caffeine-related habits that may affect your chances for an early miscarriage.In a new study , published online last week in the journal Fertility and Sterility, researchers followed 344 heterosexual couples for several weeks before and after they became pregnant. Each partner in each couple recorded how much caffeine, alcohol, and vitamins they had every day throughout the study.Unfortunately, 98 of the couples — a little over a quarter of them — had miscarriages. Among those, women who were older than 35, didn't always take their vitamins, or drank more than two caffeinated drinks per day before becoming pregnant were more likely to lose their pregnancies during the study.But perhaps the most interesting finding here was that women whose partners drank at least three caffeinated drinks every day were also more likely to have miscarriages. Both pregnant women and those women hoping to become pregnant are already advised to limit their caffeine intake. However, as the researchers here also measured caffeine intake before the couples became pregnant, these results suggest that the stimulant's effects on men (and potentially their sperm ) may also have consequences.Although this study shows that there's an association between caffeine intake and miscarriages, it can't conclusively prove that one leads to the other. Plus, for the most part, a daily coffee habit is totally safe and may even have health benefits . However, as this research suggests, there may be valid reasons for limiting the good stuff — especially if pregnancy is on your horizon.