French-Brazilian Survey On Pregnancy in Sickle Cell Disease A Study of the International Sickle Cell Disease Observatory

The International Sickle Cell Disease Observatory (ISCDO) is an international group, established in 2011, including representatives from countries where sickle cell disease (SCD) is highly prevalent, in order to collect and share information of SCD patient's to improve patients care and quality of life, to define common guidelines, to develop advanced targeted approaches and transfer innovative practices worldwide.

One of the first ISCDO study is a survey of pregnancy in SCD in France and Brazil.

Pregnancy in SCD has been associated with complications and adverse outcomes with an increased incidence of vaso-occlusive, infectious, obstetrical and neonatal complications.

Recently, in Paris (France) and Belo Horizonte (BH) (Brazil), integrated care sickle-obstetric units were created, associating sickle cell haematologist, obstetrician and infectious disease specialists, experienced in the care of these high risk pregnancies. Our aim is to compare in two different geographic institutions the prognostic and evolution of SCD in pregnant women with the prospective goal to build up a clinical score in order to better determine appropriate treatment.

We conducted a retrospective study on 253 pregnancies (120 Paris, 133 BH) characterized by 147 Hb SS, 91 Hb SC, 14 Hb SBeta, 2 Hb SD hemoglobinopathy. An e-crf was developed, to screen: the pre-pregnancy, the ante-partum rates of SCD-specific and infectious complications. We compared the obstetrical and the newborns health parameters and complications, the rate of Caesarean section, the perinatal and the maternal mortality in both countries.

In both populations, 60% of women had a maternal age between 21–30 years old (yo). However, in Brazil there was a higher rate of young pregnant women (14–20 yo) (4% Paris; 20% BH) while in France, patients were older (>31 yo) (36% Paris; 18% BH).

In the history of SCD women followed in Paris we noticed that:

-Most of these patients had a severe form of SCD with 53% who had experienced an acute chest syndrome and 9% with a symptomatic cerebral vasculopathy, several infectious complications with 26% of pyelonephritis,

-A high level of obstetrical complications with 35% of miscarriage and 10% of intrauterine foetal death.

The patients followed in Paris during their pregnancy, were treated according to the French guidelines published in 2009. According to these guidelines 67% of patients were transfused and 17% patients were not transfused because of a post-transfusion reaction history.

Caesarean section was performed in most cases in both populations (79% in Paris with 23% performed in emergency; 66% in BH).

In both populations, there was 1 materno-foetal death.

Furthermore, in BH, 15 perinatal deaths and 7 patient deaths were observed. In the Paris' group, there was no other perinatal death and 1 maternal death following a post-transfusional reaction after delivery.

The key difference between the 2 study groups concerns the foetal/neonatal morbidity and mortality. These results lead us to compare the 2 health care structures to try to find out the medical guidelines to significantly reduce the frequency of these severe clinical events. In Paris, we introduce oxygenotherapy at home during pregnancy (2l/min) in patients who were transfused because of severe SCD symptomatology (33 patients) and who could not anymore be transfused because of a severe post-transfusion reaction history (11 patients). For these subgroups of patients, we found that 40% of them didn't experience any VOC complications, or preeclampsia. The introduction of oxygenotherapy at home during pregnancy might have a positive impact in reducing the occurrence of a number life threatening complications in these high risk pregnant woman especially when they cannot be appropriately transfused.

This study is the first initial step of an international effort by the ISCDO to optimise the treatment of SCD pregnant women, to harmonize the guidelines in different countries and develop new methods of diagnosis and treatment. By improving care and the sharing knowledge of these pregnancies, we would like to increase worldwide access to the development of directed family cord blood banks in families with SCD and the access to hematopoietic stem cell transplant and other innovative therapies in developing and emerging countries where SCD is highly prevalent.

No relevant conflicts of interest to declare.