Published May 16, 2000
Volume 8, Number 5

Mallinckrodt Offers Breakthrough Technology
New Fetal Oxygen Monitoring Device will Aid Obstetricians in Delivery

Debra Reisenthel of Mallinckrodt with the new OxiFirst product, the fetal oximetry unit developed by the company in Hacienda.

By Jay Hipps
Network Editor  

Mallinckrodt Inc. is only weeks away from FDA approval for OxiFirst, a new product which offers for the first time the ability to monitor the oxygen levels of a fetus during labor and delivery. 

"The results of the randomized clinical trial were presented in February at the biggest fetal/maternal medicine meeting in the U.S. and it was voted paper number one, as one of the most important breakthroughs in obstetrics today," says Debra Reisenthel, general manager of the Nellcor Perinatal Business Unit. 

The new product will fill an important gap in the menu of diagnostic tools available to obstetricians. 

"What normally happens during labor is that when the mother enters the hospital during labor, the nurses put a belt around her abdomen to monitor the baby's heart rate. If the baby's heart rate is normal, the mom goes on to deliver in the normal process," she explains. "But if the heart rate is 'non-reassuring,' (abnormal), the doctors are very concerned because they don't know if the baby has enough oxygen. This is because fetal heart rate monitoring is not very good at differentiating between a baby that's adequately oxygenated and one that is having trouble during these non-reassuring periods. Because the doctors and nurses don't know whether there is a dangerous change in the baby's oxygen level, there is much anxiety and stress when the baby's heart rate is abnormal." 

In the U.S., doctors typically respond to this condition, present in 30 to 40 percent of all labors, by intervening and delivering the baby via caesarian section or by using forceps in an assisted delivery, a cautious approach which, it turns out, is not always necessary. 

"The doctor puts the OxiFirst oxygen sensor and measures the oxygen of the baby when the heart rate pattern is abnormal, and then if oxygen saturation is normal everyone can be reassured that the baby's oxygenated and labor can continue," she says. "The system is designed to provide reassurance to doctors, nurses, and, most importantly, the family." 

The sensor is used by placing it in the womb until the end rests against the baby's cheek. Two specific wavelengths of red and infrared light illuminate into the skin and reflect off the blood back to the detector. Since blood changes color when it is carrying oxygen, these readings allow the monitor to determine the level of the baby's blood oxygen saturation level. 

The product and FDA approval have been ten years in the making, says Reisenthel, and has been in the FDA process for more than five years. 

"It took a long time to figure out the right way to get the sensor to rest on the baby's cheek, and then when we figured out how to attach it, we found out that the oxygen saturation of the fetus is very different from that of an adult," she says. 

While adult oxygen saturation is typically over 95 percent, normal fetal oxygen is in the range of 40 to 50 percent. Also, since this figure had never been known before, the company had to conduct studies which determined the critical threshold -- "the level of oxygen above which the baby will be well oxygenated. That had never been discovered before." 

While the product's ten-year development cycle offered plenty of opportunities for discouragement, the response from doctors and patients who participated in the clinical trials helped keep everyone going. 

"We have had patients tell us, 'I had a C-section the first time and now because I used your system I didn't need one the second time. I got to bond with the baby and had a much shorter recovery period.' We hear a lot of those stories.

"Of course we want the product to make money, but it's really about wanting to change the practice of obstetrics, and make a big difference for mothers and babies in the U.S. and reduce interventions and the anxiety around birth," she said. 


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