Hemodynamic adaptations taking place during pregnancy increases the risk of cardiovascular complications including acute aortic dissection (AoD) and may lead to increased maternal and foetal morbidity and mortality. Marfan Syndrome (MFS) is a pleiotropic disorder affecting multiple organ systems, including skeletal and cardiovascular systems. Cardiovascular manifestations are more common which include aortic root dilatation, aortic aneurysm, and AoD. In pregnant women, MFS is associated with perinatal loss, preterm labour and potentially a rupture of the maternal aortic arch. Early diagnosis, preventive measures, appropriate therapeutic or surgical management are crucial in reducing the morbidity and mortality burden among these patients.
A systematic review of published articles based on original studies among women with MFS who experienced AoDs during pregnancy or labour was conducted to identify the up-to-date management and outcomes. Twelve studies were selected for the review which included a total of 631 MFS patients (790 pregnancies) and 42 AoD events occurred during or after pregnancy. Prevalence of AoDs in pregnant women with MFS was estimated as 5.3 percent. The majority (93%) of patients were < 35 years of age. Rapid increase in the aortic size, age, family history of AoD, prior history of aortic root replacement or cardiovascular surgery and third trimester of pregnancy are important risk factors.
Conservative management with beta-blockers (BB) is recommended in type B dissection in the absence of complications requiring surgery. Late referrals of patients, patient decline or poor tolerance or compliance are the major challenges in BB therapy. In addition, increased risk of foetal growth restriction require close monitoring by additional ultrasonography examinations at 28 and 35 gestational weeks along with the 3 standard scans at 12, 22, and 32 weeks. Emergency surgical intervention was indicated in patients with type A (DeBakey type I and II) and complicated type B (DeBakey type III) AoDs. BB therapy required during and after surgery to prevent progression or recurrence of AoD.
The Bentall procedure is a gold standard option in type A dissection. In this procedure, aortic root replacement is performed with a valve-graft composite of either mechanical or bioprosthetic valve and the choice of valve depends on several factors. Mechanical valves require lifelong warfarin therapy which increases the bleeding risk. Biological valves address this issue as no blood thinners are required; however, they do not last long and may require additional surgery after 15-20 years. The diseased segment of the aorta and the aortic valve are removed first. Coronary arteries are then disconnected and a graft with a valve inside is sewn to the heart and to the other side of the aorta. Coronary arteries are then reconnected through two holes made in the graft. The recovery period of patients is about 2 months. Short-term complications associated with surgery include bleeding, wound infection, renal injury, myocardial infarction, arrhythmias, complete heart block, stroke and mortality. The long-term outcomes include risk of bleeding secondary to anticoagulation for the mechanical valve, thromboembolisation, infection, valve malfunction and recurrent dissection or aneurysmal formation requiring further surgical intervention. In the David procedure, the aortic valve of the patient may be repaired and re-implanted, but the valve is preserved and reconnected to a new section of aortic tissue. In such patients, lifelong anticoagulation therapy is not required. However, the risks associated with this intervention include bleeding, renal injury, myocardial infarction, stroke, and possibly death.
Surgery is usually performed after caesarean section in case of a mature foetus. Foetal outcomes were favourable in the majority of cases; however, in some cases, during early stages of pregnancy, the outcome ended with stillbirth. Maternal death is very rare.
The authors conclude that women with MFS are at high risk of AoD during pregnancy and even women with an aortic root measuring 41-45 mm should consider avoiding pregnancy. Guideline-specific management of aortic aneurysms in pregnancy will reduce the risk of dissection. The diagnosis and management of MFS both need a multidisciplinary approach and a medical team that should start working early in pregnancy or even earlier. Further studies are needed to optimize medical and surgical approaches in addition to preconception counselling in high risk patients.