Thanks to the development of specialized surgical techniques, it’s now possible to correct some defects when a baby is still in the womb. Some procedures are still experimental, but they may be the baby’s only chance, and many parents see this as a risk worth taking.
There is only a small number of pioneering surgeons involved in the highly specialized field of fetal surgery, and the number of defects they can help is limited, but research is continuing. New methods are constantly being tried and evaluated, and as the diagnosis of fetal defects improves, it’s getting easier for doctors to decide if surgery is appropriate.
ULTRASOUND-GUIDED SURGERY
In the more straightforward types of fetal surgery, thin needles are inserted through a mother’s abdomen and womb and into the amniotic sac. Ultrasound allows the surgeon to see the baby and manipulate the needles (only one at a time is used) to take blood or tissue samples or give the baby any drugs or blood transfusions that are necessary.
Using ultrasound-guided techniques, surgeons are able to treat a growing number of life-threatening conditions. Rhesus and other incompatibilities between the immune systems of mother and baby may be corrected through intrauterine blood transfusions. Drugs to correct fetal heartbeat irregularities and destroy tumors may be injected into the baby; minute drainage tubes (shunts) that prevent further buildup of fluids may be inserted to drain excess fluids from the baby-for instance, from the brain in cases of hydrocephalus-and to clear urinary tract blockages. Ultrasound is also used to guide the tiny forceps and scalpels with which surgery can be carried out
Intrauterine blood transfusions In some cases of Rhesus incompatibility, in which a mother’s blood is Rhesus- (Rh-) negative and her baby’s Rh-positive, the baby may become dangerously anemic. If this happens, he’ll be given one or more blood transfusions into one of the blood vessels in the umbilical cord to keep him going until he can be delivered safely. Fresh Rhesus-negative blood will be injected slowly, in amounts related to the baby’s estimated weight and the seriousness of the anemia.
Blood transfusions made to a baby in the womb have a good success rate, but in some severe cases, Rh incompatibility causes miscarriage or stillbirth, despite numerous transfusions. Until recently, if transfusions were unsuccessful, there was nothing more that could be done. Research is underway, though, to find out whether injecting the baby with donated Rh-negative bone marrow will stimulate him to become Rh-negative and so remove the incompatibility.
A more uncommon type of incompatibility between a mother and her baby results in the mother’s producing antibodies that destroy the baby’s blood platelets. These platelets help blood to clot, and without them the baby could be in danger of suffering a hemorrhage and dying. This situation can now be prevented by giving the baby transfusions of platelets and, in severe cases, donor antibodies that counteract those of his mother.
Shunts for urinary tract problems Some unborn babies suffer a condition called hydronephrosis. In this, one of the baby’s kidneys becomes swollen with urine because the ureter that drains it is narrow or blocked. If left untreated, this can lead to severe kidney damage; if it affects both kidneys, it can cause kidney failure. Hydronephrosis can sometimes be corrected by the insertion of shunts by means of fetal surgery.
OPEN FETAL SURGERY
This is an even more extraordinary technique, used to correct some fetal defects that cannot be treated by ultrasound-guided surgery. It involves opening up a woman’s womb and partially removing her baby so he can be operated on. Open fetal surgery has been used to repair diaphragmatic hernias-when a baby has a hole in his diaphragm that allows his intestines to protrude into his chest cavity and damage his lungs-and to remove certain types of tumors.
The operation Ultrasound-guided techniques are always carried out under local anesthetic, but for open fetal surgery, both mother and baby need a general anesthetic. When the anesthetic has taken effect, the surgeon makes an incision in the mother’s abdomen to expose her womb, and uses an ultrasound scan to find the exact position of the placenta. The amniotic fluid is then drawn off and kept warm. Next, an incision about five inches (12 cm) long is made in the womb and amniotic membranes, taking care to keep well away from the placenta to avoid damaging it. The baby is eased gently out through this opening, just far enough for the surgeon to be able to repair the defect.
After the operation Once the surgeon is finished, the baby is carefully replaced in his mother’s womb, along with the amniotic fluid. A small amount of antibiotic is added to the fluid to prevent Infection. The incisions in the amniotic membranes and the womb are closed with absorbable stitches and surgical glue, and the incision in the abdomen is stitched together.
The mother rests in bed after the operation, and she and her baby are intensively monitored. Although generally healthy, most babies who undergo open fetal surgery are born before term, usually by cesarean section.
Tagged under:blood transfusions drainage tubes fetal surgery forceps immune systems mother and baby Pregnancy Care
