Mosaic Trisomy 16
When the result of my triple test indicated a high risk of downs syndrome (1/14), I opted for the new non-invasive blood test (NIPS) available at a University hospital as an alternative to amniocentesis. After a few weeks the results came back with the rare Mosaic Trisomy 16. Unfortunately the news arrived via the Dr performing amniocentesis at a local hospital rather than the University hospital. He told us that T16 was a rare condition which could result in multiple disorders and mental handicap. He arranged for an "emergency" amniocentesis the next day. Fortunately we received more reliable information rather quickly from a Professor in genetics at the University hospital, where the amniotic fluid was tested. We were devastated when the amniocentesis showed T16 cells in the amniotic fluid but were reassured that the level was low (14/200 or 7%)… The Professor explained that with a clear scan and low percentage, we could hope for a good outcome, but he also advised that current knowledge is lacking due to lack of data etc...in summary his opinion gave us optimism. He recommended specialised antenatal follow up as the next step. We decided to go ahead with the pregnancy, despite all the uncertainties.
To help us get though the remaining months, we started to implement a de-stress plan. This included some antenatal massage and relaxation sessions with my midwives, acupuncture and a healthy diet recommended by an antenatal dietician. My husband and I planned a few relaxing weekends away, leaving our eldest daughter at the grandparents place. A few months after the amniocentesis we got some encouraging news from the geneticist - after culture, the T16 cells had disappeared which could mean that the bad cells did not develop well compared to the healthy cells. Although we did not fully understand the meaning of this, the news helped us to feel more optimistic and relaxed about the pregnancy. However we also started to get some worrying results from the ultra sounds. The Drs had detected strong prenatal indicators (80% chance) for coarctation of the aorta - a serious congenital heart disorder which requires operation in the first few weeks following birth. The operation is most successful from 3kg, and our baby would not be bigger than 2.5 kg.
Having read the academic articles on T16, and studied data sent to us by Rosalyn at DOC 16, we expected our baby to come early. After counting down the pregnancy weeks one by one, we were astonished when she arrived at term (39 weeks +2)! I went into hospital because my waters broke and a few contractions started. However on arrival at the hospital my contractions went away. Even a long walk in the morning did not start labour. After about 11 hours they decided to give me a gentle induction. The baby was not reacting well to the nonstress test monitor so they hooked me up to another machine which connected to the baby's head. After the first contraction they saw baby was definitely suffering so they rushed me off for an emergency c-section. As the baby was just 2.02 kg at birth, and all babies lose weight after birth, she needed to go to intensive care (NICU). During her two weeks in NICU she was also monitored for the suspected heart condition. The first post-natal ecocardiogram showed that she had an unusual heart structure but probably no coarctation. The second eco confirmed that her aterial duct had closed without danger. A later check up with the paediatric cardiologist confirmed that there was no coarctation and no other heart condition either! Our daughter also underwent various ultrasounds, bloodtests and check-ups but no anomalies were found. More importantly, she displayed no clinical problems at all.
For me there are two miracles to our daughter's birth. Having spent most of the pregnancy worrying about pre-mature birth and heart anomalies she was born full term with a perfect heart.
When our daughter turned 6 months ( a year after the first T16 diagnosis), the geneticist contacted us again to inform us that they had found a mosaicism for trisomy 16 in an estimated 75% of the placental cells. A malfunctioning placenta probably explains why our daughter was born so small (IUGR).
At 6 months our baby is still small for her age but she has displayed impressive catch up growth. She is a very beautiful, normal looking blue-eyed baby. She is meeting her developmental milestones and is especially communicative and smiley.
I would like to express heartfelt gratitude to Rosalyn, Samantha and the mums on the DOC 16 network. Thanks to DOC 16, families with this rare diagnosis can be brought together via the internet. You provided us with the invaluable moral support we needed to get through this stressful pregnancy.
*Zoe is not our daughter's real name.