There is strong evidence for the use of routine antibiotic prophylaxis in people undergoing uterine aspiration for abortion. People who received antibiotics were 0.59 times as likely to experience post-abortion infection compared to those who received placebo in a Cochrane review of 15 randomized controlled trials (Low 2012). This protective effect was evident in people with and without risk factors (history of PID, positive CT, or pre-procedural BV). Limited evidence suggests that routine antibiotics are optional for asymptomatic people undergoing uterine aspiration for early pregnancy loss (Goranitis 2019).

Evidence supports pre-procedure dosing of prophylactic antibiotics for maximal effect, and the shortest possible course to give the lowest risk of adverse reactions and antibiotic resistance (Achilles 2011). Effective regimens include metronidazole, tetracyclines (e.g. doxycycline) or azithromycin. There is little data to support post-procedure antibiotics (Achilles 2011).


Misoprostol and other methods of cervical ripening for uterine aspiration have been well researched. While cervical preparation with misoprostol is generally safe and may decrease procedure time, it is not routinely recommended for uterine aspiration under 12 weeks gestation. This is due to increased waiting time, bleeding, cramping, other side effects, and minimal demonstrated benefit for ease of dilation or pain (Ipas 2021, Kapp 2010, Allen 2007). It is recommended to consider cervical preparation in adolescents (especially > 12 weeks), when an initial dilatation attempt has been challenging (SFP 2016). Misoprostol can be administered vaginally, sublingually, and buccally. Evidence-based recommendations when using misoprostol include 400 mcg sublingually 1-2 hours prior to the procedure, or 400mcg buccally or vaginally 2-3 hours prior to the anticipated procedure (NAF 2022, Meirik 2012, Saav 2015). An alternative regimen using 600 mcg misoprostol 1.5 hours prior to the procedure was found to be non-inferior with improved patient acceptability in the late first trimester (Dean 2017). One non-misoprostol regimen to consider is mifepristone 200 mg orally 24-48 hours prior to the anticipated procedure (NAF 2022).


Rh alloimmunization may jeopardize the health of a subsequent pregnancy. While past guidelines recommended all Rh-negative abortion patients be tested and receive anti-D immunoglobulin, new evidence has called this practice into question. Flow cytometry studies show first trimester fetal red blood cell exposure remains below the calculated threshold for maternal Rh sensitization until after 12 weeks of pregnancy (Chan 2021, Horvath 2020, Hollenbach 2019, Weibe 2019).

  • Rh testing must be offered to people with unknown Rh status > 12 weeks LMP and anti-D IG offered to patients > 12 weeks who are Rh negative.
  • For patients < 12 weeks by LMP, may forego Rh testing and Rh-D IG for aspiration or medication abortion (NAF Update 5-2022; WHO 2022).


  • A person > 12 weeks LMP declining Rh testing or anti-D IG should sign an informed waiver, including a patient who desires no future children.
  • Documentation may be by onsite testing, outside source, or self-report.
  • Document discussion and waiver for Rh testing as appropriate.
  • When Anti-D IG indicated, use 50 mcg at < 13 wks, or 300 mcg at > 13 wks.
  • Second injection indicated only if last > than 3 weeks earlier (Bichler 2003).
  • Anti-D antibodies may be present if a patient had anti-D IG injection within the last 3 months or was sensitized from a prior pregnancy.
  • For sensitized individuals, an additional anti-D IG injection is not indicated.


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