May 11 is Mother's Day!  And while many women spend a good part of their adult life (read college years) trying to avoid getting pregnant, infertility is on the rise as many women wait to start a family while pursuing their careers.But what many women don't realize is that what you eat prior to pregnancy is just as (if not more) important than what you eat once you're expecting.  Below are some guidelines of what to eat and what to avoid to improve your chance of conceiving.Bite this:Whole grains.  Researchers reviewing diets from the Nurses Health Study have found that choosing higher fiber carbohydrates (whole wheat bread, brown rice, oatmeal) improve the chance of ovulation as they have a more positive effect on insulin levels, which affect fertility.Not that. Women attempting to get pregnant should avoid/limit easily-digested carbohydrates (read cake, pie, doughnuts, candy, regular soda), as they interrupt the balance of hormones needed for pregnancy.  They may also lead to excess weight gain, which impacts chance of pregnancy.Bite this:Healthy fats.  While foods containing fat tend to be higher in calories, it is the type of fat that matters when it comes to fertility.  Studies show that women consuming mono and poly unsaturated fats from nuts, seeds, olive and canola oil have better chances at pregnancy than those consuming unhealthy fats (see below).Not that:Trans fat. There are many reasons to avoid trans fat- mainly to do with your arteries and risk for heart disease.  Trans fat is the type found in highly processed foods (like stick margarine and commercial cookies) as well as fast food.  Research indicates that even 4 grams of trans fat per day can impact ovulation.Bite this:Beans.  While beans may not be popular due to their "gassy affect", scientists believe protein from plant sources improve chance of ovulation over animal sources.  Dried beans, tofu, nuts & seeds, whole grains and vegetables all provide protein.  Beans are also a source of folic acid- a B vitamin needed to prevent spina bifida.Not that:Animal protein.  Research suggests too much animal protein (beef, chicken, pork) may affect chance of ovulation.  Consume animal protein in moderation (3-4 x/week) as it is a good source of iron, which is needed in higher amounts during pregnancy.Bite this:Full fat dairy products.  Yup- you read that correctly.  Scientists evaluating the Nurse's Health Study diet database found that those consuming more full fat (read ice cream, whole and 2% milk) had higher rates of fertility than those consuming lower fat dairy products.  Researchers believe the fatty acid conjugated linoleic acid may be protective.  Aim for 3 servings/day, 2 being full fat.Not that:Low fat dairy products.  Consuming low fat dairy products (skim, 1% milk) have been linked with higher rates of infertility according to the Nurse's Health Study.Bite this:Prenatal vitamin.  Even if you're not planning on becoming pregnant, up to 50% of pregnancies are unplanned and all women of childbearing age are advised to take a multi-vitamin (or prenatal) containing the RDA for folic acid to prevent birth defects such as spinal bifida.Not that.  Caffeine and alcohol.  Not surprising, risk for miscarriage increases with excessive caffeine consumption- especially when combined with smoking.  And while the jury is still out regarding alcohol (some doctors say "ok" in small amounts, others advise against it), I'd advise avoiding booze when trying to conceive and especially during pregnancy.