Maternal PKU: The Journey

Once I found out I was pregnant, I told my PKU team right away, and they let me know to start weekly blood work to monitor my phenylalanine levels throughout my pregnancy.

When I first got pregnant, I was eating 25g of natural protein a day, and getting 40g from my formula for a total of 65g a day. I was also taking kuvan and palynziq to try to get my levels down.

I started diligently tracking my protein intake. I found it helpful to use ChatGPT, and I would enter something like this:

Today I've had 1 sugar free vanilla latte from starbucks, 1 grilled cheese sandwich from starbucks, a stirfry with jasmine rice, carrots, broccoli, bok choy, and soy sauce, and a caesar salad with a tablespoon of parmesan cheese. How many grams of protein have I had today?

And it would reply:

Here's your updated protein breakdown for today, without the grilled cheese sandwich.

Food	Protein
Starbucks grande sugar-free vanilla latte (2% milk)	13 g
Jasmine rice (1 cup cooked)	4 g
Carrots, broccoli, and bok choy (1–1.5 cups)	3–4 g
Soy sauce	1 g
Caesar salad (romaine and dressing)	1–2 g
Parmesan cheese (1 tablespoon)	2 g
Total	24–26 g

Estimated protein today

25 g

I found this to be so helpful tracking my protein throughout my pregnancy, and helped me keep my levels in perfect range the whole time.

After I met with my OB, I told her I had PKU and she referred me to a Maternal Fetal Medicine (MFM) clinic. Because PKU can slow growth and development in the baby, they wanted to check in and do frequent ultrasounds to make sure she was measuring on track. These ultrasounds started as every other month, then gradually became once a month, until my last appointment at 35 weeks where I "graduated" from MFM because my baby was "giving PKU the middle finger" given that she was measuring 8lbs 8oz at that appointment.

I didn't mind having extra ultrasounds at the MFM, because I got to see my baby more often.

Because she was growing so well, it was clear that she needed more protein, as I was getting blood levels like 1, 0.8, 0.6. My PKU team started with taking away my kuvan, so I was just on Palynziq. Then she needed even more so I added 20 more grams of protein. I was at 45g of natural protein and 40g of formula equaling 85g of protein a day! Then she STILL needed more so I dropped from two injections of palynziq a day to one. Because she doesn't have PKU, her enzyme was breaking down all the protein my body couldn't, making it so that I could take in more.

Throughout my pregnancy, my PKU doctors kept an eye on my OB chart, and my OB kept an eye on my MFM chart, and my MFM kept an eye on my PKU chart. I'm so grateful for teams that collaborated on my care and made me feel covered. One MFM doctor I talked to told me that he sees one PKU patient every 2-3 years and so he was excited to meet me.

If you're feeling nervous about having a baby when you have PKU, I hope my experience of close care, healthy growth, and in range levels will make you feel more at peace. Doctors in the past have tried to scare us out of having children, I know a girl with PKU who was told she'll never have kids, but it's just ignorance. We know now people with PKU can deliver beautiful and healthy babies. Take my Gianna for example :).