The fetus's blood supply normally travels from the placenta through the umbilical cord and into the fetus's belly button. Vasa previa is an abnormal condition in which one or more of the fetus's blood vessels travels independent of the umbilical cord and the placenta and crosses the entrance to the birth canal beneath the fetus. There are two variants of vasa previa. Type 1 results from fetal blood vessels leaving the protection of the umbilical cord prior to the cord's insertion in the placenta and running independently before being inserted into the placenta; Type 2 results from fetal blood vessels running between lobes of a multi-lobed placenta.
What is the danger of vasa previa?
The danger of vasa previa is that when the cervix dilates or the membranes rupture (i.e., when your water breaks), the fetus's unprotected blood vessels can tear, causing rapid fetal bleeding that can quickly lead to fetal death or serious fetal injury such as cerebral palsy. Even if these unprotected fetal blood vessels do not tear, they can become compressed when the fetus drops in the pelvis. The compression of these vessels can compromise the fetus's blood supply and cause oxygen deprivation, which in turn can lead to fetal death or serious injury such as cerebral palsy.
What are the risk factors for vasa previa?
There are several conditions that significantly increase the risk of vasa previa. One such condition is a low-lying placenta or placenta previa. Another condition that significantly increases the risk of vasa previa is a bilobed or succenturiate-lobed placenta. (Normally, the placenta is a single organ. A bilobed placenta is an abnormality in which the placenta is divided into two parts, each with its own attachment to the uterine wall. The two parts are connected by thin segments of placenta or by blood vessels. When the extra lobe of placenta is much smaller than the main placenta, it is called a succenturiate placenta or lobe.)
Yet another condition that significantly increases the risk of vasa previa is called velamentous insertion of the cord. Normally, blood vessels run from the placenta to the baby via the umbilical cord. Velamentous insertion of the cord means that these blood vessels travel fully exposed across the amniotic membranes before they come together in the protective umbilical cord.
Marginal insertion of the cord also greatly increases the risk of vasa previa. Normally, the umbilical cord inserts near the center of the placenta. Marginal insertion of the cord exists when the umbilical cord inserts at the outer edge of the placenta.
Other risk factors for vasa previa include in-vitro fertilization; carrying twins, triplets, or other multiple pregnancies; and a history of uterine surgery, such as C-sections or D&Cs.
What are the signs and symptoms of vasa previa?
Vaginal bleeding, particularly at the time of spontaneous or artificial rupture of membranes, is the primary sign of vasa previa. However, there are often no signs or symptoms of vasa previa.
How is vasa previa diagnosed?
Antenatal diagnosis of vasa previa can be accomplished through any of the following means:
- By using an amnioscope. An amnioscope is a tube-shaped device that is used for direct visualization of the amniotic membranes;
- By vaginal exam;
- By blood tests to detect the presence of fetal blood in patients who present with vaginal bleeding;
- By ultrasound and transvaginal color Doppler studies.
How is vasa previa treated?
Women who are diagnosed with vasa previa prenatally are often hospitalized during some or all of their third trimester (beginning at about 30-32 weeks of gestation) and then undergo scheduled C-section at 35 weeks of gestation. The objective of this treatment is to closely monitor the situation and then deliver the baby before any effacement and dilation of the cervix begins, as these processes greatly increase the risk of membrane rupture and consequent fetal hemorrhage from vasa previa.
If vasa previa is not diagnosed prenatally and is only diagnosed when vaginal bleeding accompanies membranes rupture, treatment involves emergency delivery of the baby coupled with immediate blood transfusion and aggressive resuscitation.
How does vasa previa lead to cerebral palsy and other serious injuries?
If not diagnosed and treated, vasa previa can lead to fetal hemorrhage (severe blood loss). If this blood loss is not immediately reversed, through emergency delivery, blood transfusion, and aggressive resuscitation, the baby can suffer serious brain damage from lack of oxygenated blood to the brain. This brain damage can result in cerebral palsy.
Medical malpractice and vasa previa
The medical literature demonstrates that infant mortality from vasa previa can be all but eliminated through timely prenatal detection of the condition, followed by C-section delivery before the rupture of membranes. For this reason, careful doctors screen their prenatal patients for vasa previa. This screening includes attempting to identify placental umbilical cord insertion during the routine second trimester obstetric ultrasound exam, and transvaginal color Doppler sonography of the region over the cervix in all women at increased risk of vasa previa (i.e., those with second trimester low-lying placentas, IVF pregnancies, those with accessory placental lobes, and those with abnormal umbilical cord insertion) in whom vasa previa cannot be excluded by transabdominal sonography.
If your baby was seriously injured, suffered cerebral palsy, or died due to undiagnosed vasa previa, medical malpractice may have been the cause. To find out, you should call a law firm such as Pittsburgh-based Berger & Lagnese with experience handling birth injury medical malpractice cases involving vasa previa and cerebral palsy. The lawyers at Berger & Lagnese will evaluate your vasa previa case for free and help you find out whether your baby's cerebral palsy resulted from medical malpractice.