Women and girls with haemophilia: Lessons learned.

Severe and moderate factor VIII (FVIII) or IX (FIX) deficiencies in female carriers of haemophilia are rarely observed, but mild deficiency is quite frequent, although insufficiently recognized and registered. The confusion between the genetic diagnosis of the carriership, mainly assessed at adult age and the diagnosis of the bleeding disorder for those who have low factor levels often prevents early diagnosis of a potential bleeding risk. The factor levels in obligate or potential carriers of haemophilia can be assessed during childhood, possibly apart from genetic assays. The absence of early recognition of the bleeding disorder precludes the anticipation of menarche and the prevention of potential heavy menstrual bleeding to heavy menstrual bleeding. Standardized bleeding assessment tools (BAT) have demonstrated that women and girls with haemophilia (WGWH) have increased bleeding scores as compared to the general female population, however weakly correlating with factor levels. More recent evidence has highlighted that hemarthroses affect 4% to 19% of carriers and that some of them could experience sub-clinical joint bleeding. Desmopressin for women with FVIII deficiency and abnormal ISTH-BAT scores had a significantly lower FVIII response to DDAVP compared to those with normal bleeding scores, which could at least partially explain more postsurgical bleeding. Management of delivery of haemophilia carriers requires attention to the risks of maternal bleeding, the risks of foetal bleeding, preconception and prenatal care, strategies to reduce maternal bleeding, choice of mode of delivery to reduce foetal/neonatal bleeding, and postpartum care. Either prior to pregnancy, or during early pregnancy, a plan should be developed that addresses the needs of both the mother and her unborn baby. If the unborn baby is a male proven to be or potentially affected by moderate or severe form of haemophilia, there is a risk of severe foetal bleeding, so a planned caesarean delivery may be preferred. If the unborn baby is a carrier, or potentially affected carrier, there is still the risk of non-severe bleeding so invasive foetal procedures and operative vaginal delivery (forceps or vacuum) should be avoided. Further studies based on large cohorts will help the community to favour earlier diagnosis, increase knowledge on WGWH and promote better care.