Doppler 'a great addition' in risky pregnancies. (Fewer Inductions, Better Outcomes).

BIG SKY, MONT. -- Just how useful is Doppler ultrasound surveillance of highrisk pregnancies?

It's useful enough that ob.gyns. at Geisinger Health System, the nation's largest rural HMO, routinely ask women with high-risk pregnancies to drive up to 2 hours one way to undergo Doppler assessment daily or weekly "It's been a great addition to our armamentarium," Dr. Jodi Schucker said at an ob.gyn. update sponsored by Geisinger Health System.

She cited a systematic metaanalysis of all published data on Doppler surveillance conducted by the Cochrane Collaboration, a group of evidence-based-medicine advocates. The metaanalysis concluded that Doppler assessment of high-risk pregnancies improves obstetric outcomes. There are fewer prenatal hospitalizations, fewer labor inductions, no significant impact on cesarean section rates, and a possible reduction in perinatal deaths.

"This is a very positive recommendation to use Doppler," said Dr. Schucker, a perinatologist at Geisinger Medical Center in Danville, Pa.

The two most widely used Doppler measurements are of the umbilical vessels and the middle cerebral artery. Uterine artery Doppler hasn't proved very helpful. An abnormal uterine artery Doppler result has been shown to carry a mere 18% positive predictive value for development of compromise in the setting of fetal growth restriction (FGR).

Middle cerebral artery Doppler assessment is based upon the physiologic phenomenon whereby a stressed fetus will preferentially shunt blood to the brain and heart, Increased middle cerebral artery perfusion is an early compensatory reaction to FGR. When serial Doppler assessments subsequently demonstrate loss of this cephalization of blood flow, they provide a guide as to when to deliver the baby to maximize neonatal outcome. Often the loss of this brain-sparing effect ...