(247) Characterization of Pregnancy in Women of Childbearing Potential with ASCVD or Likely Familial Hypercholesterolemia: US Claims Analysis

Background:
Familial hypercholesterolemia (FH) is a genetic condition characterized by the presence of high serum total cholesterol and low-density lipoprotein cholesterol that may lead to premature atherosclerotic cardiovascular disease (ASCVD). Women with FH or ASCVD have a unique lifetime risk as current clinical guidelines advise against use of most lipid lowering therapies (LLTs) during pregnancy. In the US general population, the CDC reports a crude annual pregnancy rate of 85.6 per 1,000 women aged 15-44, however, pregnancy rates among women with FH or ASCVD are currently unknown.

Objectives:
Among women of childbearing potential (WOCBP) (12-51 years old) with evidence of ASCVD or likely FH, estimate the overall and annual incidence of pregnancy and explore the demographic characteristics and use of LLTs after ASCVD/FH diagnosis among study population.

Methods:
We utilized Optum Clinformatics, a large, geographically representative US claims database, to identify WOCBP with a diagnosis of either likely FH or ASCVD to calculate the overall and annual incidence of pregnancy. WOCBP with an initial diagnosis of ASCVD or FH (index date) were identified during the study period (1/1/2016-12/31/2022). We assembled a cohort of WOCBP who were continuously enrolled and had claims for either ASCVD or likely FH. We calculated standardized overall and annual pregnancy incidence based on the age distribution of the 2020 US Census population. We described demographic characteristics and estimated use of LLTs after ASCVD/likely FH diagnosis among the pregnant and non-pregnant cohorts.

Results:
Within the study period, the crude overall incidence rate of pregnancy among WOCBP with ASCVD/likely FH was 24.87 (age-adjusted rate: 57.4) per 1,000 person-years (PYs). The annual age-adjusted rates steadily decreased during the study period. The most recent (2022) annual crude rate was 21.6 (age-adjusted rate: 47.0) per 1,000 PYs. Among females with and without evidence of pregnancy, the mean age at index date was 33.0 years (standard deviation (SD): 6.6) and 42.9 years (SD: 8.2), respectively. The mean age of pregnancy was 33.6 years (SD: 6.6). Compared to women without evidence of pregnancy, there were slight but statistically significant (P <0.01) ethnoracial differences and they were significantly less likely to use statins (40% vs. 15%) or ezetimibe (2% vs. 1%). In both cohorts, <1% used PCSK9 inhibitors and 0% used other LLT classes after ASCVD/FH diagnosis.

Conclusions:
Our results indicate that the annual pregnancy rates in 2019 in WOCBP with ASCVD/likely FH are approximately four times lower than the general population. This may be due to adherence to the current clinical guidelines, but research is needed to further explore the observed differences in this population.