Foetal physicians - a new genre in medical speciality

REVATHI, WITH Rhesus (Rh) negative blood had lost six pregnancies in succession due to Rh incompatability. It would have been an encore with the seventh too. As she lived in a small town her doctors were at a loss to correctly diagnose the problem. But this time a correct diagnosis of her problem and treatment by a Chennai based doctor ensured the delivery of a healthy baby.

Sujatha was 25 weeks pregnant and to her dismay was informed that her foetus was suffering from hypothyroidism. Timely treatment ensured Sujatha also delivering a healthy baby.

Conceiving after a long time, Malathi was shocked to learn that her foetus had a large opening in the spinal cord and had slim chances of survival after delivery. With great reluctance she agreed to go in for an abortion.

Amravathi and her husband were very particular to have a baby boy. Using the facility that had mushroomed in her town she was able to know the sex of the foetus and readily underwent abortion.

News of Amravathi and her likes using ultrasonography to determine the sex of the foetus and aborting it when it is a female is an old story. But in stark contrast are pregnant women like Revathi, Sujatha and Malathi using the same tool to test the skills and expertise of the doctors and the limitation of the technology. The facility now ubiquitous in India is routinely used to screen the functional well being of the foetus and at its worst for sex determination. Most doctors have rarely harnessed its full potential. The situation is no different whether in small towns or in cities like Chennai.

At the most, the facility had been used to diagnose the chromosomal abnormality. Not any longer. Thanks to the expertise of two doctors in Chennai, ultrasonography is breaking free of its stigma and becoming a reliable and life saving therapeutic facility for the foetus. "We use this facility to study every organ of the foetus including the condition of the heart valves and treat the foetus in case of certain complications," said Dr. S. Suresh, Director of the Foetal Care Research Foundation, Chennai. In other words, a new speciality in the medical filed, foetal medicine, is emerging.

The most common therapeutic procedure is when the foetus is iso- immunised. In addition to blood groups, every individual may or may not have a Rh factor. A person is Rh positive when he has a Rh factor and Rh negative when he does not have one. A foetus with Rh positive blood is at risk when the mother has Rh negative blood. This is not a problem when both mother and foetus are Rh negative. Neither is it when the foetus is Rh negative and mother is Rh positive as Rh negative has no antigens for the mother to develop antibodies.

The problem typically crops up when the mother develops antibodies to Rh positive and some of these cross the placenta and enter the foetus's blood circulation. "Once this happens, the mother's antibodies destroy the haemoglobin of the foetus, rendering it extremely anemic which at times can lead to the death of the foetus," explained Dr. Gita Arjun, Director and Obstetrician and Gynaecologist, Dr. E.V. Kalyani Medical Centre, Chennai. Once formed, the antibodies cannot be removed from the mother's blood. Treating the foetus therefore becomes paramount to prevent its death.

The mother develops Rh positive antibody under two situations. Either the mother has been given a blood transfusion with a wrong Rh factor in the past or it can happen during delivery of the first baby when the placenta gets disrupted and the baby's blood cells enter the mother's blood circulation. Very rarely do the red blood cells of the foetus find their way into the mother's blood circulation during the pregnancy itself. The first baby is thus unaffected in most cases and is born healthy despite Rh factor incompatability.

When antibodies are already present in the mother after the first delivery, the danger of losing pregnancies depends on the amount of antibodies present. It generally increases with the mother's blood receiving more Rh positive antigens from the foetus in subsequent pregnancies at the time of delivery. This results in every incompatible Rh factor foetus becoming anemic earlier than the previous one. Medical intervention to prevent death of foetus is therefore imperative. The decision to start the treatment would depend on the anemic status of the foetus.

"We transfuse O negative blood to the foetus to treat its anemia. The treatment generally starts at the fifth or sixth month of pregnancy and is done three or four times at 2-3 weeks interval and the baby is delivered as soon as it is mature enough to survive outside the womb," Dr. Gita Arjun said. The amount of blood to be transfused each time is determined by testing the anemic status of the foetus. Generally 100-120 ml of blood is transfused through the umbilical vein or portal vein. Paralysing the foetus for 1-2 hours is imperative to prevent it from moving during transfusion. "Blood transfusion to the foetus after delivery will continue till such time the mother's antibodies become non-existent. The antibodies will be present in the baby for a maximum period of three months after delivery," said Dr. Suresh.

A pregnant woman with Rh negative factor is always tested for Rh positive antibodies initially. If tested negative for antibodies then the tests are repeated in the fifth and eighth month of pregnancy. The baby's blood is tested for antibodies immediately after birth. If absent Anti-D immunoglobulin injection is administered to the mother within 72 hours after delivery to mop up any Rh positive antigen that may have come from the baby during delivery. This injection thus prevents the formation of Rh positive antibodies in the mother.

"The basic problem arises because many pregnant women do not get their blood tested for Rh factor. The prevalence rate of Rh negative is around 10 per cent in India. Unfortunately, some of the pregnant women do not get their Rh factor tested especially in small towns," Dr. Gita Arjun says.

Foetal physicians treat a host of other ailments too. Hypothyroidism can be seen in some foetuses even when the mother has no thyroid problem. "This condition in babies can lead to mental retardation. And though it can be treated even immediately after delivery, intervention at the foetal stage can help the foetus have a better IQ," said Dr. Suresh. Hypothyroidism can be treated when detected at the foetal stage. The earliest it can be detected is 24 weeks after conception. Here unlike in the case of Rh factor immunisation, the medicine is injected into the amniotic fluid. "The foetus swallows the amniotic fluid immediately once the medicine is injected," he clarified. The injection is administered at weekly or biweekly intervals till delivery.

Similarly, in some cases, fluid accumulates in the chest cavity of the foetus. This prevents the lungs from developing normally. Babies born with such a problem have very slim chances of survival, as the lungs have not formed well. In such cases the fluid is drained using a stent.

Another area where foetal therapy comes into play is in reducing the number of foetus when it is more than two. This generally happens in the case of assisted pregnancies where more than one fertilized egg is placed in the uterus to increase the chance of pregnancy. "Foetal reduction is resorted to as there is a high risk of premature labour after the fifth month when there are many foetuses," Dr. Suresh said.

Ultrasonography has grown in sophistication since its introduction in the 1970s. "It can be used to detect simple abnormalities like an extra finger or correctable abnormalities like kidney and intestinal obstruction or lethal abnormalities such as absence of the skull or a large opening in the spinal cord," Dr. Gita Arjun said. "While detecting lethal abnormalities can help make a decision to terminate the pregnancy, the correctable ones can eliminate the need to start investigations from scratch after delivery. This saves precious time to save the life of the baby."

R. Prasad

In Chennai

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