Background:  Women seeking abortion care may be referred to another abortion provider for a higher level of care (i.e. to a tertiary care center).  Reasons for referral include history of prior cesarean delivery, concern for abnormal placentation, and obesity.  It is unknown how many women are referred to other providers for the above reasons, and there are no defined criteria for such referrals, only post-abortion hemorrhage risk categories from the Society of Family Planning).  Unfortunately, referral for a higher level of care requires delaying abortion care, potentially increasing the risk of complications associated with increasing gestational age.  
Objectives: This study had two overall goals.  First: to quantify and describe the patients seeking abortion who referred by community abortion providers to a single tertiary care center for a higher level of care, and to compare their complication rates with non-referred patients receiving abortion care at the same institution.  Second: to gain a better understanding of criteria used by abortion providers in the region when referring patients for a higher level of care for their abortion.   We were specifically interested in referrals due to patient obesity, history of prior cesarean delivery, or concern for abnormal placenta), and whether providers pre-screen patients over the phone to identify those in need of referral before coming for an appointment.  After collecting all of this patient and provider information, we hope to suggest practical measures to optimize the referral process.
Methods: This study was conducted in two parts.  First, data from patients that received abortion care at a single tertiary care center between July 2016 and March 2019 was reviewed.  Information collected included referral status, specific reason for any referral, and any adverse events the patient experienced when obtaining their abortion.  Descriptive statistics and chi-square test were used to compare the referred and non-referred patients and their outcomes.  The second part of the study was an anonymous online survey (from March – May 2019) of regional abortion providers regarding their practice setting and criteria for referring patients for a higher level of care, specifically related to obesity, prior cesarean delivery, and concern for abnormal placenta.  Descriptive statistics were utilized.
Results: Women who were referred to the tertiary care center for history of prior cesarean delivery, concern for abnormal placentation, or obesity, and received surgical abortion care at ≥14 weeks gestation, did not have statistically significant differences in complications compared with non-referred patients.  Provider survey results show that most regional providers report referring 1-5% of patients for a higher level of care.  Responding providers refer patients for concern for abnormal placenta based on specific suspicious ultrasound findings (68%), do not refer for obesity (65%) or history of cesarean delivery (74%).  However, free-text responses indicate that providers consider multiple factors when deciding to refer patients for a higher level of care.  Nearly all providers that use patient pre-screening feel that it is helpful.  
Conclusions: Referred patients and non-referred patients do not experience a significant difference in complication rates, however this does not necessarily indicate that the referrals were unnecessary, given that the care was provided in a tertiary care setting.  Regional abortion providers must consider multiple factors when referring patients for a higher level of care.  Pre-screening appears to be helpful to providers and those not currently pre-screening patients should consider implementing the practice.  A more comprehensive and objective tool for evaluating wither patients seeking abortion require referral for a higher level of care is an area for further study.  This study is specific to the Southern California region and may not be generalizable in other regions or practice settings.