Intra-Uterine Diagnosis

Intra-uterine approaches are therapeutic procedures aimed at correcting, even if only temporarily, some situation involving the fetus, which has compromised its intra-uterine well-being, until the birth, when a more effective intervention can be performed.

- Intra-uterine Transfusion
- Intra-uterine Surgery

Intra-uterine Transfusion

In special circumstances, intra-uterine transfusion can become necessary, especially for treating effects caused by RH or Kell alloimmunizations, as well as by Thalassemia major, to give a few examples. In cases in which the Rh negative mother is alloimmunizated, antibodies are produced, destroying Rh positive fetus’ blood cells. The fetal organism tends to compensate this destruction producing more mature cells.

Intra-uterine transfusion, in these cases, uses type “O” negative irradiated blood, stopping the action of maternal antibodies. Our current protocol procedure verifies the paternal genotype in order to investigate if the couple would be likely to have a RH negative fetus. We request a indirect Coombs examination to guide the pregnant woman regarding the level of alloimmunization.

Serial Ultrasonometries are requested starting from 18 weeks of pregnancy, with the purpose to seek for signs of fetal hydropsy, such as: increased placenta thickness, ascites and pleural-pericardic effusion.

In 1998, we started to follow a routine that includes amniocentesis, not only for spectrophotometry of amniotic fluid, but also for fetal blood typing through PCR. Amniocentesis is a valid resource because it is less invasive and because it allows fetal monitoring, associating the results obtained with the ultrasonometric data.

We avoid the use of cordocentesis for propaedeutic purposes, using it only in the imminence of intra-vascular transfusion. The main parameters that lead to this procedure are the hematocrits and fetal hemoglobin. The volume of transfused blood in calculated from 30 to 50 ml per kilogram of the fetal weight, estimated based on ultrasonometry. After each transfusion, the goal is to keep the hemoglobin concentration in normal levels (12,0 to 13,0 g/dL).

Recent studies have shown that IF there is any difficulty in performing intra-vascular transfusion, intra-peritoneal transfusion may be used with equivalent effectiveness.

Intra-uterine Surgery

Although experimental, such as the use of laser to treat the posterior urethral valve or fetal-fetus transfusion syndrome, this is an interesting surgical approach method, which can provide numerous benefits.

We currently use derivations for the amniotic cavity, using the catheter known as "pig tail". In recommendations due to urinary tract obstruction, we evaluate kidney functions through biochemical dosages of the fetus’ urine ( beta2microglobulin), sodium and osmolarity, ultrasonometric parameters of functionality or anatomic preservation of kidney parenchyma and, more recently, through organ biopsy.

Vesico-amniotic derivation is performed in surgical environment and the mother receives anesthesia. In well selected cases, both pulmonary and pleural derivations tend to provide good results.

There is, today, a trend to moratorium for central nervous system derivations, especially in cases of hydrocephaly. Those derivations are not considered concretely benefic to the newborn’s evolution.

Another alternative for fetal treatment is the puncture of single or multiple pulmonary cysts such as those who occur in cystic adenomatoid lung disease.