VASA PREVIA QUESTIONS AND ANSWERS

Why do so many vasa previa babies seem to be breeched or traverse?

Most likely the transverse lie is related to the low-lying placenta. When the placenta occupies the lower portion of the uterus, it prevents the head from engaging (going into the lower segment of the uterus, and the pelvis). Therefore, the baby may not be head first. The position of the VP Baby may also reflect an attempt by the baby to avoid compression of the velamentous vessels. 

What kind of success does the new 3D ultrasound have with diagnosing VP? How does it compare to the Color Doppler ultrasound?

The constant improvement in ultrasound will allow more accurate diagnosis of VP.

Why is it that so many OB/GYN’s don't seem to know up-to-date information on vasa previa?  And why do most of them seem to take a very "can't do anything about it anyway" attitude towards vasa previa?

Vasa previa can be diagnosed prenatally. The time has come when physicians should look actively for it. The tragedy of fetal death from a ruptured vasa previa is preventable in the majority of cases. There is little education opportunity for the OB provider to study Umbilical Cord Accidents.

What is the likelihood of having a repeat "low-lying" placenta? 

There are no studies looking at this issue.

Can bi-lobed placenta lobes grow together and become one huge massive placenta?  In my case, I had a bi-lobed placenta with vasa previa and it seems that the lobes grew together into a complete placenta previa.  It seems the placenta was just one huge, thin mass.

The placenta can change during pregnancy but little is documented as to how.

How often do bi-lobed placentas recur? 

The answer to this is not known.

Is there any risk with a bi-lobed placenta if the connecting vessels aren't crossing the cervix?

A bilobed placenta carries some risk even when the connecting vessels do not overlie the cervix.  The connecting vessels may rupture. Velamentous insertion, even when not vasa previa (not overlying the cervix) is more frequently associated with fetal abnormalities and poor obstetric outcome. The risk is lower than with vasa previa, but still these patients may require more intensive monitoring.

Once vasa previa is diagnosed prenatally, what should the course of action be...

...complete bed rest or just activity restrictions?

...when should you be admitted to the hospital?

...should you be monitored constantly while there?

...what course of action should be taken for preterm contractions?

...at what point should the baby be delivered early even if the lungs may not be mature rather than risk rupturing?

I ask these because my doctors kept telling me there's no "cookie cutter recipe" for treating it and getting me to the point when they want to do the C-section

When vasa previa is diagnosed prenatally, it makes sense to hospitalize the mother in the third trimester (after 27-28 weeks), and deliver her by cesarean section at about 36 weeks. She may require delivery earlier should bleeding occur. Why hospitalize the mother? In the event that the membranes should rupture and bleeding ensues, rapid delivery is possible in hospital, whereas in the time it takes the mother to arrive in hospital from home, the fetus will most likely be dead. Doctors regularly admit women with preterm labor, pre eclampsia, placenta previa and other conditions which are not associated with perinatal mortality anywhere near as high as vasa previa.

Thirty-six weeks appears a reasonable gestational age to schedule delivery. Most fetuses will have mature lungs at this gestational age. Certainly, death of lung immaturity at 36 weeks is virtually unheard of, provided the mother is not diabetic and the dates are accurate. Compare this with the risk of death or poor outcome should the membranes rupture.

Monitoring in hospital does not necessarily need to be excessive. A fetal heart tracing each day should be adequate (this is done in most hospitals for all obstetric in patients). The reason for admission is to be able to act in the event of rupture of the membranes and bleeding, not primarily for monitoring.

Preterm contractions should be treated with drugs to stop them (tocolytics). Persistent preterm contractions leading to labor are an indication to consider Cesarean delivery, especially if the fetus is mature and steroids have been given.

Bed rest is not essential. However, a reduction in activity is desirable as is avoidance of sexual intercourse, and the mother should be admitted in the third trimester as previously discussed.

Education of the patient and expectant delivery at the least evidence of labor is essential!

After having vasa previa once, should I be insistent with my doctor to have a color Doppler ultra sound with any future pregnancies?

There is no evidence of VP repeating in subsequent pregnancy. An ultrasound review of the placenta and cord would be important anyway. 

What would be my percentages of this happening again after having a bi-lobed placenta?  Some of what I have read said it would happen again.

The answer to this is unknown.

Is velamentous cord insertion dangerous by itself, without having vasa previa?

Yes.

How common is velamentous cord insertion?

Published sources suggest that velamentous insertion occurs about 1-2 times per 100 pregnancies. Figures vary depending on whose study you read. Vasa previa is generally said to occur about 1:2-3000 pregnancies.

Is there any way to detect velamentous cord insertion before birth?  I had a color ultrasound, and they said they were unable to tell.

Yes.  Velamentous insertion can be detected prior to birth using ultrasound, certainly with color Doppler ultrasound.

Do you know of any cases where a woman has had vasa previa and/or velamentous cord insertion in more than one pregnancy?

The VPF has learned of one woman who had vasa previa during two subsequent pregnancies; however this information has not been documented.  Her first VP pregnancy ended in fetal demise and the second in fetal survival. None of the doctors we’ve spoken with have ever known of any woman who had vasa previa or velamentous cord insertion in more than one pregnancy.

What are the causes of velamentous cord insertion?

Placental remodeling.

Has vasa previa or velamentous cord insertion been related to a higher incidence of birth defects than those born without vp or vci?

No, most of these babies are totally normal.  VCI and vasa previa are associated with a higher incidence of poor outcome.

If a woman has velamentous cord insertion, but not vasa previa, is it safe to deliver vaginally?  The doctors believe I had vci, not vp, with my last pregnancy, and we still hemorrhaged.

Though it is common to deliver with a VCI without detriment to the baby, VCI carries risk even when not a vasa previa. VCI may be allowed a trial of labor if the vessels are away from the cervix. However, close continuous monitoring is mandatory. The vessels could rupture, and also pressure on the vessels could lead to fetal compromise. This can be detected early by monitoring.

What are common factors in each of the women who have had vasa previa?

Vasa previa does have an association with a low-lying placenta, which may be associated with previous uterine surgery including prior cesarean, maternal smoking, multiple pregnancy (twins, triplets, etc), and also with assisted conception (artificial insemination, in-vitro fertilization, etc).

What lifestyle factors or medical conditions increase the likelihood of vasa previa?

The answer to this is unknown.  There are no lifestyle changes that affect the incidence of vasa previa. However, vasa previa does have an association with a low-lying placenta, which may be associated with prior cesarean, maternal smoking, multiple pregnancy, and also with assisted conception.
 

What can I do to reduce my chances of a second occurrence in a subsequent pregnancy?

The answer to this is unknown.  Again, recurrence risk is low...

What is the likeliness of a reoccurrence of vasa previa or velamentous insertion in a subsequent pregnancy?

This is unknown.  No one has data on recurrence risk for vasa previa; nevertheless it is extremely low....You cannot reduce your risk of a recurrence. Don't worry, the risk is low. See a perinatologist to do a thorough sonogram. There are several other complications of pregnancy that can be dangerous. The risks of any of these are much higher than the risk of recurrent vasa previa. See a good OB/GYN and one that you trust and have good rapport with.

How many babies still die due to vasa previa even with a diagnosis during the pregnancy?

Published data on vasa previa mortality shows a rate of 30-100%.  Our data suggest that survival is practically 100% if the diagnosis of vasa previa is made prenatally, and the patient is delivered by elective cesarean section. We have 2 prenatally diagnosed babies on record that died.  However, they died of other complications of pregnancy such as prematurity and placenta previa.

How long is it advisable (medically) to wait before becoming pregnant again after a STAT C-section for vasa previa?  Am I more at risk for a low-lying placenta, etc if we conceive quickly?

There is recent evidence suggesting that it is ideal to wait about 4-6 months after a cesarean section before becoming pregnant again. This is because of a slight increase in risk of a uterine rupture. So, 4-6 months should be fine. This has no bearing on the risk of a low-lying placenta, even though a previous cesarean section is one of the most important risk factors for a low-lying placenta. That is a risk no-one can change (except for avoiding a cesarean section in the first place!)

If my doctor knew that I had a low-lying placenta AND a bilobed placenta, should he have also known that I was a VERY good candidate for vasa previa? I was monitored very closely having 4 sonograms (including one Color Doppler sonogram) and was still not informed that something could be very wrong.  How could he not have known?  

Unfortunately physicians are often poorly educated about vasa previa; furthermore they often consider the condition to be rare. Therefore, they are often caught totally unaware when vasa previa does occur. The key is in a high index of suspicion.  So the message we are trying to get out is that all physicians should be suspicious and look for vasa previa. Even the best sonographer will miss vasa previa if not on the lookout for it. There definitely needs to be more education about ultrasound of the placenta and umbilical cord.

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The issue of umbilical cord accidents (UCA) is that 25% of pregnancies have some involvement.  Looking at cause of death, 2-4 cord accidents per 1000 births occur without the awareness of the OB community. UCA-VCI/VP are part of an overall pregnancy process which goes unaddressed in OB Conferences. Education is needed to improve the awareness of UCA and its losses which exceeds the 1-2 per 1000 stillbirths due to pre eclampsia.