Pierre Robin sequence is named after the French doctor, Pierre Robin, who first described it in 1923. Pierre Robin Sequence is a sequence of events that leads to airway problems. Babies are born with a small lower jaw, which causes the tongue to roll back and cause an obstruction or “airway blockage”. This may develop early after birth. Most babies with Pierre Robin sequence also have cleft palate. This is because the palate is composed of 2 vertical shelves that become horizontal and fuse during the fetus maturation. With a smaller lower jaw, the tongue rolls back and migrates also up and prevents from those 2 palatal shelves to fuse. The Cleft Palate Foundation says about one out of every 2,000 to 30,000 babies has Pierre Robin sequence.
The single initiating cause is the hypoplastic development of the lower jaw with consequential posterior positioning of the tongue base that occurs between the seventh and eleventh weeks of gestation. The posterior position of the tongue impairs the retroglossal airway space and closure of the posterior palatal shelves that may result in a cleft of the secondary palate. Since these things happen one after another (in sequence), this problem was named Pierre Robin sequence. Beyond the isolated sequence, PRS may occur in approximately 25% to 35% within the context of a formal syndromic condition such as Stickler, Treacher-Collins, Nager Syndrome, and a multitude of others. One-half of babies with Pierre Robin sequence also experience additional issues. One chromosomal problem commonly seen in babies with cleft palate is velocardiofacial syndrome. This is caused when a piece of chromosome 22 is missing. A chromosome test may be done to see if your baby has this syndrome.
Another problem seen in babies with Pierre Robin sequence is Stickler syndrome. These babies have a group of findings that occur together including small bones of the face, eye abnormalities, joint problems and hearing loss. Stickler syndrome is usually caused by mutations in the collagen gene and is inherited directly from parent to child. It may also occur as a result of new changes in collagen and appear in babies with no other affected person in the family. Children with Pierre Robin sequence are carefully examined for signs of Stickler syndrome and other genetic conditions. A geneticist is a type of doctor who can help find out if your baby has such a syndrome. The geneticist may also be able to answer questions about your pregnancy and whether there were other things that could have affected your baby.
In the neonate with Pierre Robin Sequence, respiratory compromise the primary concern. The posterior position of the tongue obstructs the airway and causes respiratory distress. With microretrognathia there is lack of structural support of the tongue and the tongue falls downward and backward (glossoptosis) into the posterior pharyngeal space, obstructing the epiglottis. In this position, the tongue acts as a “ball valve” allowing egress of air, but hampering inspiration. Thus, energy expenditure is diverted from normal growth and development (weight gain) to the work of inspiratory effort (sternal retractions). Labored breathing becomes more apparent with supine position. Chronic airway obstruction may lead to hypoxia, failure to thrive, and cor pulmonale. Mortality rates as high as 30% have been reported.
Babies without breathing problems should sleep on their backs to reduce the risk of sudden infant death syndrome (SIDS). Babies with Pierre Robin sequence, however, should not sleep on their backs, because of their airway problems. Most babies with Pierre Robin sequence should sleep on their stomachs or their sides. If your baby has obstructive sleep apnea, your doctor may recommend use of a apnea monitor.
You may also hear your baby having trouble breathing when he is in his car seat. Your doctor should order a breathing study to be done while your baby is in his car seat, to be sure he will be able to breathe well sitting up in the seat. Your doctor may say you should use a special care bed instead of a car seat. Car beds let your baby travel lying on his stomach, so the tongue can fall forward and help the airway stay open. If your baby has a home cardiac apnea monitor, it should also be used during travel. You should use a card bed that meets federal motor vehicle safety standards, just like regular baby care safety seats.
In the first weeks and months of life your baby may need special help with his breathing and eating. A team of doctors, nurses and other health care specialists can provide the care needed to help your baby do well. If your baby shows any signs of airway problems or has a very small chin, your doctor should do tests to find out if your baby is having breathing problems.
Feeding problems in the infant with PRS are thought to be due to the abnormal anatomic position and the inadequate neuromuscular control of the tongue. Furthermore, a cleft of the palate when present with PRS further compounds the ability of the child to feed with the inability to generate adequate suction. In such situations, feeding should be upright with a specialized cleft palate nipple/bottle that does not require suction. The patient’s weight should be followed closely to insure that they are gaining weight appropriately. If the infant is unable to gain appropriate weight in spite of these interventions, a feeding tube should be considered. Moreover, when severe airway obstruction is present energy expenditure is diverted from normal growth reflected by a lack in weight gain, surgical intervention should be considered.
A number of noninvasive diagnostic studies are important in the diagnosis and eventual management of these patients.
The sleep study may show that your baby just needs to sleep on his stomach to help him breathe. At home, most babies will need a machine called an apnea monitor. This will check your baby’s heart rate and breathing constantly. The machine will alert you if the baby’s heart rate is too fast or too slow, or if he stops breathing. If the doctor says your baby needs the monitor, you will be taught how to use it and what to do to help your baby if there is a problem.
If the sleep study shows your baby does not have enough oxygen in his blood, the doctor may decide to treat him with oxygen at home for a while.
If the airway obstruction is very serious, some babies while in the hospital may need extra treatment for the obstruction. Sometimes a tube is temporarily put into your baby’s nose (nasophayngeal intubation) or through his mouth (endotracheal intubation).
Some babies need an operation to help them breathe better. If needed, Dr. Tahiri will decide which operation is best for your baby. The current gold standard is called mandibular distraction osteogenesis. In surgery, distraction devises are attached to the lower jawbone on each side of the face. A screw is turned daily to increase the distance. This makes the jawbone grow longer. Moving the lower jaw gradually forward will help move the tongue forward also making the baby’s airway larger. Sleep studies will help the surgeon know when the screws no longer need to be turned and the devices can be surgically removed. It usually takes the jaw around three to four weeks to reach the desired length and then another six to eight weeks for the jaw to heal completely.
D. Tahiri has an extensive experience in treating babies with Pierre Robin Sequence and performs routinely mandibular distraction.