At The Bump’s anatomy ultrasound we found out that she has SUA (Single Umbilical Artery), meaning that her umbilical cord only has one artery, rather than the two that normal babies have. And at her follow up we found out that The Bump has IUGR associated with the SUA
So if you are reading this you may have received the same news, or are interested in learning more…like I was. BUT I will warn parents-to-be against turning to the vast interwebs of information on the subject. Because there are so very many horror stories out there about SUA. I learned the hard way and freaked myself out. I did find a few other bloggers that wrote about their experience with SUA, and they also warned about researching too much. But I just wanted to know what we were dealing with, as I got conflicting information from the OB performing the ultrasound and my midwife. Not what you want when you hear “bad” news about your unborn child.
Here’s what you need to know about SUA:
- SUA affects 1 out of every 100 pregnancies (~1%). Most pregnancies with a SUA have a normal prenatal course and a healthy baby at delivery, especially if there are no other findings on the ultrasound.
- No one knows for sure why this happens in some babies. It is believed that one artery may simply stop growing as it develops or perhaps the very early umbilical artery does not divide properly. The following features in a pregnancy make it more likely that a SUA will be seen:
- Multiple gestation (twins, triplets, etc)
- Caucasian ancestry
- Female fetal sex
- Mothers over 40
However, SUA can be seen in any pregnancy, even if none of these features are present.
- Although one artery can certainly perform the job of two and sustain a perfectly healthy pregnancy, there are some concerns for the pregnancy when SUA is seen on ultrasound. Another concern raised about SUA is the possible increased risk for slow fetal growth, preterm delivery, or stillbirth. However, not all studies agree that there is a greater risk for pregnancy complications. Your OB provider routinely monitors the growth of the baby. If there are concerns that the baby seems smaller than expected, another ultrasound in the last few months of pregnancy may be done to check the baby’s growth.
IUGR (Intrauterine Growth Restriction) simply means that Baby is not growing as they should be. The most common definition of intrauterine growth restriction (IUGR) is a fetal weight that is below the 10th percentile for gestational age as determined through an ultrasound. This can also be called small-for gestational age (SGA) or fetal growth restriction.
There are basically two different types of IUGR:
- Symmetric or primary IUGR is characterized by all internal organs being reduced in size. Symmetric IUGR accounts for 20% to 25% of all cases of IUGR.
- Asymmetric or secondary IUGR is characterized by the head and brain being normal in size, but the abdomen is smaller. Typically this is not evident until the third trimester.
One of the most important things when diagnosing IUGR is to ensure accurate dating of the pregnancy. Gestational age can be calculated by using the first day of your last menstrual period (LMP) and also by early ultrasound calculations. We had a hard time dating conception due to my Endometriosis, but once we had the first ultrasound our gestational age was confirmed and the due date. But I feel pretty confident that I know when we conceived.
Once gestational age has been established, the following methods can be used to diagnose IUGR:
- Fundal height that does not coincide with gestational age
- Measurements calculated in an ultrasound are smaller than would be expected for the gestational age
- Abnormal findings discovered by a Doppler ultrasound
Despite new research the optimal treatment for IUGR remains problematic. Most likely the treatment will depend on how far along you are in your pregnancy.
- If gestational age is 34 weeks or greater, health care providers may recommend being induced for an early delivery.
- If gestational age is less than 34 weeks, healthcare providers will continue monitoring until 34 weeks or beyond. Fetal well-being and the amount of amniotic fluid will be monitored during this time. If either of these becomes a concern, then immediate delivery may be recommended.
Depending on your healthcare provider, you will likely have appointments every 2 to 6 weeks until you deliver. If delivery is suggested prior to 34 weeks, your healthcare provider may perform an amniocentesis to help evaluate fetal lung maturity.
So I know that this all sounds sort of scary…because I am a bit freaked out by it all. But before you freak out, talk to your OB, Midwife or care provider to get the specifics of your baby.