Women who are diagnosed with thrombotic micro angiopathy during pregnancy are at risk for serious long-term complications (Egerman, 1996). he Parkland experiences included a mean 9-year surveillance period (Dashe, 1998). hese women had multiple recurrences; renal disease requiring dialysis, transplantation, or both; severe chronic hypertension; and transfusion-acquired infectious diseases. Two women died remote from pregnancy-one from dialysis complications and one from transfusion-acquired HIV infection.
In nonpregnant women who have recovered from thrombotic microangiopathies, persistent cognitive defects and physical disabilities have been reported (Kennedy, 2009; Lewis, 2009). Interestingly, as discussed in Chapter 40 (p. 745), these cognitive defects are very similar to those found in long-term surveillance studies of women who had eclampsia (Aukes, 2009,r2012; Wiegman, 2012).
Obstetrical hemorrhage may infrequently be the consequence of an inherited defect in a protein that controls coagulation.
Both types of hemophilia are examples. Severity reflects plasma factor levels and is categorized as mild-levels of 6 to 30 per cent; moderate-2 to 5 percent; or severe-less than 1 percent (Arruda, 2015).
Hemophilia A is an X-linked recessively transmitted disorder characterized by a marked deiciency of factor VIII. It is rare among women compared with men, in whom the heterozygous state is responsible for the disease. Heterozygous women have diminished factor VIII levels, but almost invariably, the homozygous state is requisite for hemophilia A. In a few instances, it appears in women spontaneously from a newly mutated gene. Pregnancy-associated acquired hemophilia A from antibodies may result in severe bleeding-related morbidity (Tengborn, 2012). Christmas disease or hemophilia B is caused by severe deiciency of factor IX and has similar genetic and clinical features.
he risk of obstetrical bleeding with these is directly related to factor VIII or IX levels. Afected women have a range of activity that is determined by random X-chromosome inactivation-Iyonization-although activity is expected to average 50 percent (Letsky, 2000). Levels below 10 to 20 percent pose hemorrhage risks. If levels fall to near zero, this risk is substantial. Pregnancy does aford some protection, however, because concentrations of both these clotting factors rise appreciably during normal pregnancy (Appendix, p. 1256). Treatment with desmopressin may also stimulate factor VIII release. Risks are further reduced by avoiding lacerations, minimizing episiotomy use, and maximizing postpartum uterine contractions. Operative vaginal deliveries should be avoided.
here are few published experiences during pregnancy.
Kadir and coworkers (1997) reported that 20 percent of carriers had postpartum hemorrhage. Guy and associates (I992) reviewed five pregnancies in women with hemophilia B, and in all, outcomes were favorable. They recommended factor IX administration if levels are below 10 percent. Desmopressin has been shown in selected cases to reduce obstetrical bleeding complications (Trigg, 2012).
If a male fetus has hemophilia, the risk of hemorrhage increases after delivery in the neonate. his is especially true if circumcision is attempted.
If a mother has hemophilia A or B, all of her sons will have the disease, and all of her daughters will be carriers. If she is a carrier, half of her sons will inherit the disease, and half of her daughters will be carriers. Prenatal diagnosis of hemophilia is possible in some families using chorionic villus biopsy (Chap. 14, p. 293).
Preimplantation genetic diagnosis for hemophilia was reviewed by Lavery (2009).