Introduction:
Some maternal genetic disorders increase the risk for hypertensive disorders of pregnancy (HDP) due to cardiovascular effects inherent to the disorder. While guidelines suggest thresholds for starting aspirin (ASA) prophylaxis in patients with certain risk factors, there is no clear guidance for patients with genetic conditions. This study aims to evaluate the use of aspirin prophylaxis and the development of HDP in patients with genetic disorders.

Methods:
A retrospective analysis of maternal and fetal outcomes for pregnancies of patients with genetic disorders (determined by a molecular diagnosis or clinical criteria) who delivered at a single institution with two delivery sites between 2013 and 2024. Only the first delivery was included in the analysis if a patient delivered more than once. The primary outcome measures were the use of aspirin prophylaxis during pregnancy and the development of HDP. Non-parametric statistical methods were employed.

Results:
We analyzed the records of 106 patients with genetic disorders. There was a wide range of genetic disorders represented including chromosomal (18, most commonly mosaic Turner syndrome), renal (18), inborn errors of metabolism (16), connective tissue (10) , skeletal (9), multi-system disorders (8), neurocutaneous (6), endocrine (6), RASopathies (4), neuromuscular (3), albinism (3), vascular (3), hematologic (1), and oncologic (1). Based on guidelines for classifying patients by risk of developing HDP, the patients were split into low risk (12), moderate risk with < 2 moderate-level risk factors (41), moderate risk with >= 2 moderate-level risk factors (29), and high risk (24). Twenty-three patients received ASA prophylaxis, including 8/41 patients in the moderate risk with < 2 risk factors, 4/29 in the moderate risk with >=2 risk factors, and 11/24 in the high-risk group. We found no documentation of ASA prophylaxis counseling during prenatal care for 57/83 (69%) who did not receive it. For some patients, reasons for not initiating ASA prophylaxis when indicated by risk status included late entry to prenatal care, medical contraindication, patient declined, patient already on therapeutic anticoagulation, and incorrect risk classification. Most patients were classified as moderate risk, however, 33/83 (40%) who did not receive ASA were incorrectly classified as low or moderate risk, but were high risk based on their maternal genetic condition and other risk factors for HDP. 9/23 (39%) of the patients on ASA prophylaxis and 18/83 (22%) of those not on ASA prophylaxis developed HDP.

Conclusion:
For patients with genetic disorders, it is important to consider the patient’s risk for HDP and initiate ASA prophylaxis when indicated. Many genetic disorders place patients at a higher risk for HDP and implementing ASA therapy may prevent this complication. However, we found that the genetic disorder was often not incorporated into the patient’s risk determination and aspirin was not started. For the best possible outcomes, clinicians should consider the risk of HDP inherent to the patient’s genetic disorder.