This rare and often treatable pregnancy condition was brought to my attention by Carol Prentice, on behalf of the Int’l Vasa Previa Foundation. Some of the information is fairly “technical” but generally clear and informative.
Vasa previa occurs when fetal blood vessel(s) from the placenta or umbilical cord cross the entrance to the birth canal, beneath the baby. Vasa previa can result resulting in rapid fetal hemorrhage. This occurs from the vessels tearing when the cervix dilates, or membranes rupture or lack of oxygenor (if the vessels become pinched off as they are compressed between the baby and the walls of the birth canal). The aberrant vessels result from velamentous insertion of the cord, bilobed or succenturiate lobed placenta.
Vasa previa can be asymptomatic but can also present with sudden onset of abnormally heavy or small amounts of painless vaginal bleeding in the second or third trimester of pregnancy. Source of blood should always be investigated to determine whether the blood is maternal or fetal.
Rarely reported, occurs in 1:2500 to 3000 births with a fetal mortality rate estimated to be as high as 95 percent if not diagnosed antepartum. (1-2)
When properly diagnosed antepartum, prognosis of survival is very good. The fetal mortality rate is very low when an elective C-section is performed after fetal lung maturity is adequate.
Ante partum Diagnosis
Changing current routine obstetrical ultrasound protocols to include checking the placental cord connection for velamentous cord insertion during all routine obstetrical ultrasounds is recommended (preferably with color Doppler). All suspected cases of velamentous cord insertion, placenta previa, low-lying placenta, multi-gestational pregnancies, and multi-lobed placentas need to be checked for vasa previa with advanced ultrasound techniques, specifically level 2 ultrasound of the lower uterine segments and/or transvaginal color Doppler ultrasound. (3) Vasa previa can be detected during pregnancy as early as the 16th week with use of transvaginal sonography in combination with color Doppler. (4) Infant death from vasa previa is preventable if diagnosed antenatally.
Vasa previa might be present if any (or none) of the following conditions exist: low-lying placenta (may be caused by previous miscarriages followed byand/or curreting of the uterus (D&C;), or uterine operations, which causes scarring in the uterus), bilobed or succenturiate-lobed placentas, pregnancies resulting from in-vitro fertilization or multiple pregnancies.(5-6) .Vasa previa bleeding is painless. Other OB or birthing bleeding complications are not necessarily painless.
When diagnosed antepartum, treatment plans could include the following: use of tocolytes to stop all uterine activity; bedrest; no sexual intercourse, vaginal exams, lifting, heavy straining during bowel movements (use of stool softeners); hospitalization; fetal monitoring; steroid treatment; regular ultrasounds to monitor progression of vasa previa; determination of source of bleeding (either fetal or maternal); amniocentesis to access fetal lung maturity; steroid treatment to develop fetal lung maturity; and most importantly, elective cesarean delivery early enough to avoid an emergency but late enough to avoid complications of prematurity. When not diagnosed antepartum, aggressive resuscitation complete with blood transfusion for the infant if necessary must be planned for and/or expected. (7)
For More Information: http://www.vasaprevia.com
REFERENCES (1) Vago T. Caspi E. Antepartum bleeding due to injury of velamentous placental vessels. Obstet Gynecol 1962;20:671-5
(2) Quek, SP, Tan KL. Vasa praevia. Aust NZ J Obstet Gynaecol 1972;12:206
(3) Gianopoulos J, Carver T, Tomich P et al. Diagnosis of vasa previa with ultrasonography. Obstet Gynecol 1987;69(3 Pt 2):488-491
(4) Meyer WJ Blumenthal L, Cadkin A et al. Vasa previa: Prenatal diagnosis with transvaginal color Doppler flow imaging. Am J Obstet Gynecol 1993; 169:1627-1629
(5) Evans GM. Vasa praevia. Br Med J 1952;2:1243
(6) McAfee CHG. Placenta praevia-A study of 174 cases. J Obstet Gynaecol Br Emp 1945;52:313
(7) K.O Oyelese, M. Turner, C. Lees and S. Campbell. Vasa Previa: An Avoidable Obstetric Tragedy. Obstet and Gynec Survey 1999; Volume 54, Number 2:138-144
The International Vasa Previa Foundation Information Sheet
The International Vasa Previa Foundation (IVPF) was established in January 2001. It is a result of the vasa previa e-mail group (http://groups.yahoo.com/group/vasa_previa), founded on June 25th, 2000, for those who have experienced vasa previa in one way or another. Marlou van Dijck founded this group after the loss of her daughter, Julia, who died due to complications caused by vasa previa on May 26, 2000.
Creating a world without vasa previa deaths while supporting those whose lives have been impacted by it.
To educate the public and medical community worldwide about vasa previa and to modify medical standards and practices .To adjust the medical rules and protocols worldwide in such a way that prevents fatal outcomes.
An Avoidable Tragedy
The International Vasa Previa Foundation agrees that vasa previa is an avoidable tragedy can,and but should not be, a devastating complication of pregnancy because it can be detected during pregnancy as early as the 16th week with use of transvaginal sonography in combination with color Doppler. Despite its severity, it is commonly unknown by women, midwives, and many even obstetricians andit is rarely detected during pregnancy. And often, inadequate decisions made during labor and delivery result in fetal mortality rates estimated to be as high as 95 percent.
International Vasa Previa Foundation
2691 LA “s-Gravenzande The Netherlands
Tel. +31 174-270029
Bank account: Rabobank the Netherlands 1353.74.014
Number Dutch Chamber of Commerce (Kamer van Koophandel): 27198872
International Vasa Previa Foundation 2109 5th Street,
Moline, IL 61265 USA