‘Pre-Con’ is like PKU boot camp: painful, but necessary

The ‘Preconception diet’ is like boot camp for aspiring PKU moms. In theory, it doesn’t sound much different than our standard diet, but in practice, it requires a major lifestyle change.

I was clueless.  

When I started to think seriously about my future, I went back on diet. And though I struggled with consistency, my success (or lack thereof) was always a conscious decision. So when my husband and I started thinking about kids, I figured ‘Pre-Con’ would simply be a matter of diligence. I was wrong.

My approach to going back on-diet was extremely relaxed; I simply cut out the foods I wasn’t supposed to eat. The only thing I measured and counted were carbs; otherwise, I stuck to fruits and veggies and started taking formula again. After years off-diet, that was enough to miraculously get my blood levels back on track—and it felt like a huge feat! But over time, I watched my levels rise and fall with my will power. ...I knew I would have to get much more regimented to sustain a healthy pregnancy, but also figured it wouldn’t be any more difficult than initially re-committing to diet. Again, I was wrong.

Everything counts.

The first thing to know about the Pre-Con Diet is that it requires meticulous measuring. And while that’s true of PKU in general, by adulthood, most of us balance careful counting with studied approximation. Going out to dinner, for example, you may know the ingredients are all PKU-friendly, but the quantities have to be eyeballed. Or at work, you have a few uncounted cups of coffee to survive a crazy deadline. But if you’re counting milligrams of phenylalanine (as most on ‘Pre-Con’ do), everything counts! Gone are the days of convenient estimates and small allowances. Eating out becomes a rare phenomenon, and meals become much more daunting.

“Gone are the days of convenient estimates and small allowances. Eating out becomes a rare phenomenon, and meals become much more daunting.”

On top of that, your dietitians will likely alter your diet to ensure you’re able to control phe intake, while also increasing calories and formula. I was asked to eat the number of calories I would need during pregnancy and to take an additional serving of formula per day—while keeping my daily phe goal the same. This led to premature weight gain and often feeling gross, bloated and uncomfortable. I ate more medical foods than ever before (low protein pastas, breads, etc.) and got frequent stomach aches as my body adjusted.  ...But all in the name of a goal, right?

In order to track phe to this degree, you must keep detailed food logs. This is another common practice of PKU (especially during childhood), but one that tends to become more and more relaxed with age. But on ‘Pre-Con’ every ingredient—down to the spices you use—should be listed with precise quantities that contribute to your daily phe allowance. This same log will be analyzed by your dietitians, so even phe-free ingredients (like the oils used in cooking) are listed to account for how calories may be affecting blood results.

Most doctors recommend blood tests once or twice a week to adapt to the lab routine you’ll need to practice during pregnancy. For some, this can be done at home (and that was the case for me in the beginning, too). But I soon found the mail-in labs took over a week to get results, and began driving to my clinic—50 minutes each way!—to get them within 2-3 days. I had to get a new work schedule approved, and said goodbye to relaxing Saturday mornings at home. With that commitment, we were able to monitor my diet much more closely and make quicker adjustments to target blood levels within the 120 - 360 umol/l goal range.

It wasn’t the regiment that killed me.

All of the ‘Pre-Con’ requirements definitely contributed to a major lifestyle change. Previously, most of my social activities revolved around food. Whether eating out, traveling, or going to (and hosting) parties, everything became a much bigger challenge on ‘Pre-Con’. And the time it took to manage the diet took a big toll. Unfortunately, I watched a lot of my friends fall by the wayside. Invitations were often withheld and worse, many began to look at me like an alien creature they could no longer relate to; looks of horror and pity washed over their faces anytime I described the new regimen. It often felt like it was me and my husband against the world. And because I had been so socially active before, I felt cooped up, restless, and forgotten. ...To my husband and the  few friends and family members who were an active support through the hard days (and helped find new ways to have fun!), you’ll never know how much it meant.  

“I awaited each lab result with bated breath, and had to be picked up off the floor more times than I can count.”

But above all, what I truly wasn’t prepared to face were the factors that affected my blood results beyond my control. I thought being so committed to the diet would guarantee success. But with two blood tests every week, I soon learned how many things contribute to my shortcomings. Stress, illness, fluctuations in routine, and exercise were a new battle. I did everything I could to become a creature of habit and develop new practices that would help reduce stress and keep me healthy. But still, weeks of successful blood results were interrupted by sudden spikes and drops.

The one thing I struggled with the most was exercise. I’ve always been extremely active. Running, hiking, kickboxing, spin classes, yoga, weights...you name it. And on ‘Pre-Con’, exercise was the one thing that made me feel empowered; It was my outlet for all of the stress and emotion that came with the battle and it kept me going. But, it also became apparent that it was having a huge affect on my blood levels. We looked at increasing calories, taking additional formula, timing my food intake and blood labs to align with exercise science…everything! And still, we could not find a fix. I looked at my workouts as a lifeline and coping mechanism, so I refused to give them up and it was the one challenge no amount of discipline seemed to solve.

At one point, after almost a year of relentless troubleshooting, I felt so defeated I even started looking into adoption and surrogacy. I had truly lost faith that I could reach 8-12 weeks of consistent blood results—the benchmark for ‘Pre-Con’ success. I broke down with every bad result and at times, felt I had given up everything just to repeatedly fail. I didn’t know how much longer I could sustain the effort and awaited each lab result with bated breath,; I had to be picked up off the floor more times than I can count. But with every loss, my husband and mom stayed positive and encouraged me to keep going; they kept the faith strong when I couldn't find it for myself.  I couldn’t be more thankful to them for pushing me through. ...To those of you struggling now, if motherhood is your dream, don’t give up!

But in the end, it was a success.

By the standard rules of the Pre-con Diet, I didn’t truly succeed. I only made it to a 6-week winning streak before my blood levels dropped below goal range. And try as I might, I never got them back up to where they should be. I got pregnant unexpectedly and went into a panic as my already-low levels tanked even further.

But after the big-news, I began to recognize the many ways my grueling ‘Pre-Con’ journey actually was a success. I was able to control my phe intake with absolute precision, even as it was adjusted every few days to navigate a new metabolism. I stayed on top of it. I had learned resolve and routine, to accept new priorities, and found joy as a creative cook and virtual hermit, rather than a socialite. ...And now, I continue to ride the wave of challenges with PKU because of that training.

“I had learned resolve and routine, to accept new priorities, and found joy as a creative cook and virtual hermit, rather than a socialite.”

When i went into it, i thought ‘Pre-Con’ would simply be a lesson in how to eat low amounts of phe and never stray. But it’s really not about that at all. It’s about control—hypercontrol—and understanding how many things contribute to healthy blood levels and nutrition. With pregnancy, my protein tolerance is constantly in flux. As it changes, my levels may drop or spike out of goal range, but Pre-Con taught me how to respond, make adjustments quickly, and identify the factors (beyond baby) that may be contributing.

I absolutely encourage other PKUers to stay the course and successfully meet the specific ‘PreCon’ goals set by your clinical team. (I did fall a little short) But please go into it expecting a challenge and face it with more compassion than I gave myself. You will hit bumps in the road and be tested in new ways, but it will also serve you well and prepare you for the rollercoaster of pregnancy. Above all, know you’re not alone and that despite whatever struggles and failures you face along the way, you can do it. You’re stronger than you think.