Select the risk factors and anesthesia details for a cesarean birth. The tool returns mechanical and LMWH prophylaxis, the dose and duration, and the earliest safe time for the first LMWH dose, following the SMFM checklist line by line.
Primary source: Society for Maternal-Fetal Medicine; Patient Safety and Quality Committee; Combs CA. SMFM Special Statement: Checklist for thromboembolism prophylaxis after cesarean delivery. Am J Obstet Gynecol. 2020 Oct:B22-B23. Checklist version August 6, 2020; reaffirmed 2025. SMFM describes it as a sample that does not dictate an exclusive course of action.
Thrombosis history
Thrombophilia
Choose the highest-risk diagnosis. Definitions are those printed in the SMFM checklist.
Body mass index and weight
BMI 40 kg/m² or more changes the dose only when prior VTE or a thrombophilia is present. Weight is used for the adjusted-dose (therapeutic) calculation.
Anesthesia
Times (optional, for the first-dose calculation)
Used after general anesthesia
Leave blank if not yet removed
Special situations
How the checklist works
Every woman having a cesarean receives pneumatic sequential compression devices, placed before surgery starts and continued until she is fully ambulatory. LMWH is added only for a personal history of DVT or PE, or an inherited or acquired thrombophilia, and is continued for 6 weeks after surgery. The dose rises to intermediate when BMI is 40 kg/m² or more alongside either risk factor, and is individualized when risk factors combine. The interval before the first dose depends on the type of anesthesia and the dose level. In Consult Series #51, these recommendations are graded weak, based on low-quality evidence; the universal compression device recommendation is graded strong.
Notes on the source document
The checklist does not define "combinations of the above risk factors". The tool treats prior VTE together with a thrombophilia as a combination. BMI 40 or more with one risk factor has its own row in the checklist, so the tool does not count it as a combination.
The checklist lists protein C and protein S deficiency as low-risk inherited thrombophilias. Every listed thrombophilia, high or low risk, leads to the same 6 weeks of prophylactic LMWH.
Severe obesity without prior VTE or thrombophilia receives compression devices only. Other risk factors such as infection, preeclampsia, postpartum hemorrhage or prolonged immobility are not part of the checklist.
Doses are fixed and given as examples ("eg, enoxaparin"). Apart from the adjusted dose of 1 mg/kg every 12 hours, the checklist does not scale dose to weight.
The 4-hour interval after catheter removal applies to epidural catheters. For a single-shot spinal, only the interval from needle placement applies.
Significant intraoperative bleeding is addressed as a timing and drug-choice question, not as an indication for prophylaxis.
MTHFR mutations are explicitly not considered thrombophilias.
Publications used in this tool
Society for Maternal-Fetal Medicine; Patient Safety and Quality Committee; Combs CA. Society for Maternal-Fetal Medicine Special Statement: Checklist for thromboembolism prophylaxis after cesarean delivery. Am J Obstet Gynecol. 2020 Oct:B22-B23. doi:10.1016/j.ajog.2020.07.013Primary sourceEvery category, dose, duration and timing rule in this tool. Read from the source document; volume and issue not printed on it.
Society for Maternal-Fetal Medicine (SMFM); Pacheco LD, Saade G, Metz TD. Society for Maternal-Fetal Medicine Consult Series #51: Thromboembolism prophylaxis for cesarean delivery. Am J Obstet Gynecol. 2020;222:B11-7.Parent guidelineRecommendations and evidence grades the checklist summarizes; reaffirmed 2024, endorsed by ACOG. Citation as printed in the checklist; RefVerify pending.
Blondon M, Casini A, Hoppe KK, Boehlen F, Righini M, Smith NL. Risks of venous thromboembolism after cesarean sections: a meta-analysis. Chest. 2016;150:572-96.Meta-analysis3- to 4-fold higher VTE risk after cesarean than after vaginal birth. As cited by SMFM; RefVerify pending.
Clark SL, Christmas JT, Frye DR, Meyers JA, Perlin JB. Maternal mortality in the United States: predictability and the impact of protocols on fatal postcesarean pulmonary embolism and hypertension-related intracranial hemorrhage. Am J Obstet Gynecol. 2014;211:32.e1-9.ObservationalCited by SMFM for the reduction in maternal death with routine post-cesarean prophylaxis. As cited; RefVerify pending.
Petersen EE, Davis NL, Goodman D, et al. Vital signs: pregnancy-related deaths, United States, 2011-2015, and strategies for prevention, 13 states, 2013-2017. MMWR Morb Mortal Wkly Rep. 2019;68:423-9.SurveillanceVTE as a leading cause of potentially preventable maternal death. As cited by SMFM; RefVerify pending.