Single Umbilical Artery

LovesProphecy · #1 June 7th, 2012, 05:49 PM

I had never heard of this until yesterday when I went to ther perinatologist (sp) I was really hoping nothing would go wrong this go around as I haven't really even felt pregnant. Boy was I in for a shock. My midwife sent me to see the specialist because my 4 previous births have all been born around 34-35 weeks no real explanation as to why, she wanted to be sure it was safe for me to have a VBAC again even though I have had 3 previous to this and to make sure my cervix wasn't to thin. Because of all of this and the fact that she is 100% likly to arrive early I am now going on the once a week progesterone shots to try and lower her risk to 50%. I had the blood test to detect downes and it was negative but the risk of other issues from this have me terrified the risk of losing her is weighing me down for personal reasons that i will just say is because of a great loss.. I find myself feeling angry and scared and confused

i am only 18wks and 4day.. any advice/suggestions?

The umbilical cord normally contains 2 arteries and a single vein. Occasionally, one umbilical artery is absent, with the left artery absent more commonly than the right. Single umbilical arteries are associated more commonly with fetal anomalies than normal cords.

Single umbilical artery occurs in fewer than 1% of cords in singletons and 5% of cords in at least one twin. Single umbilical artery also occurs more often in fetal demise than in live births.[5] The incidence can be overestimated with gross examination of the cord, especially if the portion close to the placenta is examined, because the arteries may fuse close to the placenta.[6]

Single umbilical arteries are found twice as often in white women than in African American and Japanese women. Diabetes increases the risk significantly. The male-to-female ratio is 0.85:1.

Single umbilical artery is believed to be caused by atrophy of a previously normal artery, presence of the original artery of the body stalk, or agenesis of one of the umbilical arteries.

The vessels in the cord are clearly identifiable with ultrasonography. The vein is usually larger than the arteries. Single umbilical artery may be diagnosed prenatally with the finding of only 2 vessels on a cross section of the cord, or a vessel seen on only 1 side of the fetal bladder.

Of infants with a single umbilical artery, 20% or more are reported to have associated fetal anomalies[5] , including cardiovascular abnormalities, GI defects, esophageal atresia, a variety of renal defects, and multiple anomaly syndromes.[7, 8] The association with fetal defects is more striking in series reported from prenatal diagnosis than in newborn studies; this difference may be due to prenatal diagnosis occurring in a selected, high-risk population. In addition, almost 20% of cases of single umbilical artery diagnosed prenatally in a high-risk population were associated with chromosomal anomalies.[9] Trisomy 18 is the chromosomal anomaly most highly associated with single umbilical artery.

With single umbilical arteries, a 5-20% perinatal mortality rate has been reported,[10, 11, 12] although this includes fetuses with severe congenital anomalies and chromosomal defects. Two thirds of deaths occur before birth. Of the one third of neonates who die postnatally, most have associated congenital abnormalities. In pregnancies in which no fetal abnormality is found, the incidence of fetal growth restriction and small placental size is increased.[13, 12]

Prenatal diagnosis of a single umbilical artery should prompt examination for other anomalies. Because associated anomalies can occur in any organ system, consider a detailed anatomy survey whenever a 2-vessel cord is discovered. Fetal echocardiogram may also be helpful. Consider fetal karyotyping, especially if anomalies are found. Because some studies have reported an association with fetal growth retardation, consider third trimester ultrasonography for fetal growth.[11] Consider neonatal ultrasonography to examine for renal anomalies.

Dee Darling 3 · #2 June 8th, 2012, 01:18 PM

I have no experience with this. Have you talked to your peri about your concerns? What are his/her thoughts on this? How about your midwife?

I know several women have had success w/ the P17 shots (the progesterone ones), allowing them to go to 37 weeks or longer.

Please keep us posted. You and your LO are in my thoughts and prayers.

Special_K · #3 June 8th, 2012, 07:13 PM

I am 32 weeks pregnant and was told we are also missing an umbilical artery, but I was told it is fairly common and not to worry about it. I also thought I'd mention that I am on weekly progesterone shots as well since I had my daughter 9 weeks early at 31 weeks and we are still baking this time around.....yaay!

The Kimber · #4 June 14th, 2012, 01:50 PM

My daughter had this when she was pregnant with her first and everything turned out just fine.

AmyLM · #5 June 14th, 2012, 07:11 PM

My niece had just one umbilical artery. I think the only issue she has had is kidney reflux. She was on antibiotics for a year after she was born. No problems, though. ((hugs)) hang in there and try not to worry yourself too much. Make sure you ask your doctor about everything you're concerned about!