Guest Post: pregnancy with PKU, a dream come true


By | Amanda Cosburn

Becoming a mother has been a lifelong dream for me, and one that for a time I never thought would have been possible due to my health. In March 2016, my beautiful and healthy baby Girl, Madelyn came into our world, it was and is a dream come true.

Motherhood was something that would have been considered impossible because of my genetic condition. Thanks to advancements and years of research, we learned that it was possible.

I was born with a genetic metabolic disease called Phenylketonuria (PKU). PKU is when someone like me, is born without the enzyme that converts one of the amino acids in protein called phenylalanine into tyrosine. Because I don’t have this enzyme, phenylalanine accumulates in my blood and is toxic to my body and brain. When the level of PHE (phenylalanine) is too high in my blood, it causes serious side effects and a risk of brain damage or mental disabilities and handicaps.

PKU is diagnosed through newborn screening at birth. It is a simple heel-poke blood test that all babies in North America are screened for at 24 hours old. Up until the 1960s there was no screening for PKU and most children born with PKU were severely handicap and ended up living in group homes as they are completely dependent on 24 hour full care.  Since screening began in the 1960s babies with PKU are caught before damage is done and can live a long happy healthy life when treatment is followed.

A positive result for PKU means you need to start a life-long treatment program immediately to protect your brain and body. Early diagnosis is key because if not detected most babies by six months will experience brain damage. Fortunately, because of the early diagnosis through newborn screening, babies can grow up to be happy and healthy adults, like me.

However, the treatment program takes discipline and commitment. Pregnancy with PKU can cause concerns for the baby if an even more strict diet is not followed, more on that in a bit.

PHE Free Diet

Those living with PKU have to follow a restricted, low protein diet. My diet consists mainly of fruits and vegetables as well as medical foods that don’t contain protein or PHE. I also drink a PKU specific formula that is full of amino acids, vitamins, minerals and protein without PHE. The formula is essentially a crucial medication and my life support system.

This diet is very strict. Food needs to be weighed to the gram and then I count how many milligrams of PHE is in the food. If not followed to meet a daily tolerance, those with PKU can experience impairments – neurological and behavioral, and sometimes physical side effects, if the levels are too high.

It can cause mood swings, depression, anxiety, trouble focusing, retaining information, concentrating, and can cause you to lose IQ points. You can also experience tremors and headaches, to name a few. Too low, and you can become catabolic and your body starts to break down its own protein, which also can release PHE into the blood and affect your brain. 

Pregnancy and PKU

Until I was 18, I was told I would never have a baby because my PKU would make my uterus toxic and cause serious side effects to my unborn baby and myself. I was told that if I became pregnant my baby could be born deformed, handicapped or die. 

However, medical advice began to change and thankfully, we now knew that it was possible for women with PKU to have a normal, happy, and healthy baby. A healthy pregnancy would be possible if a woman with PKU worked very hard and followed a even more restricted diet and was closely monitored. This is called the maternal PKU diet. It was recommended that if a woman with PKU wanted to have a baby, she had to follow a preconception diet and treatment plan for three months before getting pregnant. This plan was recommended to lower the risk and toxicity to the fetus. 


This was the news I had always secretly hoped to hear as my deepest and most secret dream was one day to be a mother myself. Every time one of my friends got pregnant or someone close to me, I ached inside, longing to carry my own child. My arms ached to hold my child. I dreamed and wished and prayed with all of my soul to one day be able to be a mother. It took me a long time to accept that it could happen one day.

Even with the new advancements and advice, I still didn’t fully believe I would be a mother I didn’t have all the tools I needed to be successful at the maternal PKU lifestyle available to me. I also didn’t have the confidence in my ability to comply to this restrictive diet plan.

In 2014, thanks to Health Minister Terry Lake, myself, and a team of PKU advocates, we were able to secure funding for our medical foods. This helped me to be more compliant with my special diet to help me one day realize my dreams of motherhood.  

A dream come true

In May 2015 I went off birth control to ready my body to one day have a baby! Over 10 years on birth control, I expected it would take my husband and I a while to conceive…not the case. I found out on June 17th, 2015 that we were expecting!! I was nearly three weeks along already. It was a surprise as we were  not officially trying.

I was filled with so many mixed emotions, from disbelief, then to relief that it was finally my turn. I began to fear the hard work needed so that I could give this baby a good healthy start but my emotions quickly turned to pure joy. Many tears were shed in those early days. I don’t think it fully sunk in for a few weeks. I barely remember breathing. I was not on the preconception diet yet so I was terrified.  My PHE levels in my blood were not in the safe range.

I immediately called the PKU clinic in Vancouver for help, which is where my medical team who monitors and treats my PKU is located. It is the only clinic to treat PKU in adults that is located in BC. The clinic consists of two dietitians who support me and guide my diet and treatment plan and they also monitor my blood levels. The clinic also has a nurse and a specialist doctor. The first thing I needed to do was get my blood levels down to safe range. I did a home blood test immediately. I take my blood from my finger and place it on a card and courier it to the newborn screening laboratory in Vancouver where they read the results. Because PKU is so rare, we don’t have a home testing device like diabetics do. 

The best way to get levels under control is to get my diet under control. I need to be very careful about what I was putting in my body now. I started getting back on track and doing regular blood tests. While pregnant I did blood tests three times a week and drove them to our local hospital so they could send them to Vancouver.  Thankfully got the results back quickly enough that if there was a issue or to high we could correct it before damage was done to my baby. 

I had to weigh and track every bit of food I put in my mouth down to the gram. I had to count how many milligrams of PHE I was putting into my body to keep it safe and not cause any side effects to my baby. I had to meet the required amount every day and not be under or over, as both would affect my baby. The first few weeks through the morning sickness it was tough, especially keeping my medical formula down. But I knew subconsciously I had to keep every mouth full down for the health of my unborn baby. I struggled everyday not to throw it up.

Throughout my pregnancy an OBGYN and a midwife cared for me and I had specialized ultrasounds to check for deformities and issues with baby’s heart and brain. Because I did stick to my diet and controlled my levels, my baby never had any side effects from bad PKU levels.  

Had I not gotten my levels down before organogenesis started in the fetus they baby would have been deformed, had a very small head, been mentally handicapped or stillborn. I had always been told most of my life it this happened that the clinic would strongly recommend abortion, and that was also drilled into my head from an early age by  my mother. This would not be an option for me. I wanted this baby for so long, I worked so hard every day. I never wanted anything more.

I was able to get my levels down three days after the first positive pregnancy test. I got my levels into range and kept them in a stable range before the end of my fourth week of pregnancy.


In addition to my midwife and OBGYN I was also under the care of a maternal fetal specialist in Vancouver at the high-risk pregnancy clinic. This clinic is where I had most of my ultrasounds and fetal echo cardiogram done. We even saw our baby in 3D though we asked not to know the gender.  I will always remember this ultrasound the most. It was the first real look at our baby. Our first dating scan was done at six weeks but we hadn’t had another scan between then and this special anatomy scan at 21 weeks. We were looking at a real baby! We could see the little nose and cute little ears and eyes, even tufts of curly hair. We watched our baby move and roll and suck its hands. It was a powerful moment and I still remember the way the tears felt on my face and how full my heart felt. It was love at first sight. I could finally see myself counting and kissing all those fingers and toes!

Pregnancy helping PHE levels

A very interesting phenomenon occurs in maternal PKU in the second trimester. Once the baby is able to eat and break down protein in its liver, if it has the enzyme I am missing it takes my protein and breaks down the PHE and takes it out of my blood.

So my levels got even lower. Being too low can cause side effects and affect the growth of the baby, I had to start eating more protein. As my baby grew and developed and needed protein, my own tolerance to protein would increase. Because of this, while I was pregnant, for the first time in my life, I got to try new foods that I have never eaten before. My regular daily tolerance is seven grams of protein from food, and 90 grams from my medical formula that does not have PHE.  By the end of my pregnancy, I was able to eat 40 grams of protein just from food! 

However, as soon as my baby was born, I would have to give up all these new foods. I was very careful about what I introduced so I wouldn’t miss anything or struggle after my baby was born. I did enjoy being able to eat oatmeal and chow mein noodles.  I also developed a love for oreo ice cream. I never added any meat or dairy to my diet while pregnant. Instead we increased my protein with foods such as grains like rice, more of foods I could already eat, and by adding protein powder to my formula.

My pregnancy progressed well and myself and my baby were both very healthy.  I will never forget hearing my baby’s heartbeat for the very first time, or the first few flutters of movement.  I had dreamed of these moments, they beat all my expectations. I enjoyed every appointment and ultrasound.  Feeling my own baby grow and move and roll inside me gave me the strength I needed to persevere with my diet and blood tests.

With all the extra screening and appointments with my family doctor, OBGYN, midwife, fetal medicine specialist, my PKU clinic and dietician I felt so very well cared for and it continued to grow my confidence. I read all the baby books back to front. I went to meet ups and prenatal classes and prenatal fitness classes. I loved my pregnancy and my experiences. I kept a journal and recorded everything on my PKU blog and Facebook for all our friends and family. I also shared my story publicly with the PKU community so other women like me would know it’s possible for them too!

At 33 weeks my OBGYN was so impressed with my progress that my midwife was given the go ahead to deliver my baby when he or she was ready to be born.  My baby was born 10 days overdue —  a happy, healthy baby girl Madelyn,who weighed 6 lbs 11 oz, the same as her mommy did!  My dreams had finally come true and she really is everything I hoped she would be.

In my heart, long before we were ever pregnant I saw a brunette baby girl with her mommy’s curly hair and her daddy’s smile. I saw this little girl bouncing on his shoulders while walking along the beach, our family dog trailing beside us. It always made me feel whole inside. Madelyn is exactly that and I could not have asked for more. I know the angels sent her to us! She is everything I had ever dreamed of. She has fulfilled me and I feel complete.

I am so happy and blessed to have experienced a healthy pregnancy and have such a beautiful intimate birth. Surrounded by an amazing team, the love of my life Cole, our truly amazing and wonderful midwife Joanna and the fantastic nurses at the Kamloops Royal Inland Hospital.

Madelyn developed normally and she is growing and thriving and now a year old. She started walking at nine months! She knows a few words already and is very social and talkative. She knows mama, dadda, copper (our dog), hi, and yum yum!

Actually, doctors say she is very advanced for her age and size. She still wears nine month clothing but, she is meeting all of her milestones ahead of time and following her growth curve. She is a very good eater. Teaching her about food and weaning her has been a learning curve for me, since I can’t eat most of what she does. I work hard to give her a variety so she has a better relationship with food and is not a picky eater. We do baby-lead weaning and she eats everything! Her favorite fruit is banana, she loves rice, pasta, sweet potatoes, cod fish, chicken, and pork. She eats toast and muffins, oatmeal, all fruits and vegetables (especially carrots and broccoli), and so much more. She has a cow’s milk protein allergy so like mommy, we use almond milk in her food, and while cooking and baking.

However, for my own diet since giving birth and coming back to my regular protein and PHE tolerance and back down to my normal intake, I have struggled. I am having post partum anxiety and I get panic attacks. I have not been eating well or weighing and tracking my intake anymore. Life has been so busy. I don’t always find time to manage my diet or weigh and measure and prepare my meals and I am so hungry and eating over my recommended tolerance. I have learned in this past year that the first year for a mom with PKU is very hard to adjust back after pregnancy. I thought it would be easy since I did well while pregnant but, my diet lacks in nutrition and whole protein and is high in carbs and starches and sugars. I struggle with my weight, eating healthy, and staying full.  I thought my daughter would give me the incentive to stick to my restricted diet so I can be my best for her but I have definitely had my ups and downs. My PHE levels after birth took a while to come down and were high for the first few weeks, then dropped, and then went back up again. They have been mostly around 11 or 12 since because I haven’t been strict with myself.

I try every day to do better. At least I enjoy my special medical formula and drink it every day but, I am finding it hard to do my meal prep when I usually am cooking for three different diets.  I am working with my clinic again to get back on track and maybe lose some weight so I can be active with my daughter and lead by example for her.

I don’t ever want her to struggle with food, weight or activity like I have. I don’t look forward to the day I must explain my PKU to her and why mommy can’t share her foods when she tries to share with me. I sometimes wish I could eat the same healthy foods as her. I am so happy she does not have PKU. Even though there are worse health issues someone can have, and PKU is manageable, I am still relived she did not get it.

I tell myself every day is a new day and another chance to do better and try harder and fix what I didn’t do yesterday. Today I have already had my formula and some low protein bread I baked from scratch while she had her toast and banana.  

Either way,  I look forward to watching my daughter grow, helping her thrive and finding new ways to teach her and challenge her. She has taught me so much already and filled my life with so much joy and happiness. I am so in awe of this little person and that I was able to grow her and nourish her and give her the best start to life!

I will be forever grateful for advances in treatment for PKU however, PKU is still not well known. It is my mission to share my story and to spread awareness about this genetic disease. The more we know, the more we can research and evolve PKU care to improve quality life for people living with PKU. Alone we are rare, together we stand strong.

Amanda Cosburn is a mother, PKU advocate, and entrepreneur who lives in Kamploops, BC with her husband Cole, Daughter Madelyn and dog, Copper!

To learn more about Amanda’s PKU journey please visit her website, here.

“People with PKU are missing an enzyme to break down protein in food, specifically one aminio acid. This amino acid is called phenylalanine, often called PHE (pronounced fee). Since this amino acid cannot be completely processed, it builds up in the blood and excess amounts cross the blood-brain barrier. When excess amounts build up, brain damage and other neurological problems result.

“PKU is a rare and inherited metabolic disease that affects approximately 1 in 12,000 newborns in North America. Both parents must be carriers of the gene for there to be a chance that their child will have PKU.”

– The Canadian PKU and Allied Disorders Inc.

Posted by blogger. mom. beautybounter. public relations.

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