Thromboembolism (Blood Clots)

Key Points

Evidence shows that estrogens increase the risk for blood clots for pregnant and postpartum women, known as venous thromboembolism (VTE)
Risks of blood clots include deep vein thrombosis (DVT), stroke and pulmonary embolism (PE)
Guidelines have long been in place to limit a postpartum woman’s exposure to estrogens

Placental tissue contains estrogens and progestins, in varying levels based on preparation methods for consumption
Women should be informed of the potential for increased risk of blood clots when offered estrogen products, including placenta for ingestion

Estrogens pose a known blood clot risk

VTE = venous thromboembolism

CHC = combined hormonal contraceptive

COC = combined oral contraceptive

Blood clots form when blood components thicken, forming a mass within the blood vessel. Once formed, these clots are referred to as a venous thromboembolism, or VTE. They can travel to parts of your body and cause serious complications including deep vein thrombosis (DVT) and pulmonary embolism (PE) or a stroke. Among the conditions and risk factors that can cause a VTE include pregnancy and use of hormonal contraceptives. This is because the hormone estrogen, present in both the pregnancy hormonal state and in some hormonal birth control, is responsible for causing this hypercoagulation state in the body (Mayo Clinic 2018).

Estrogens pose a known risk of a venous thromboembolic event (VTE) when administered in the first few weeks postpartum. Some studies have found that progestins may also carry a risk of VTE (Pfeifer et al. 2016). “Venous thromboembolism (VTE) refers to the formation of a blood clot in a deep vein and is a rare but potentially preventable cause of death in women of reproductive age. Deep venous thromboses, which commonly occur in the legs, may break off and move into the pulmonary vasculature, which can be life-threatening. However, most venous thromboses do not result in death. Common risk factors for VTE include hypercoagulability and vascular injury. Pregnancy and the postpartum period in particular are associated with an increased risk of VTE compared with the non-pregnant state” (Pfeifer et al. 2016).

Kim and colleagues discuss risk factors for VTE in their study published on contraceptive use, stating “Pulmonary embolism (PE) and deep vein thrombosis (DVT) is a serious medical problem causing considerable morbidity and mortality. Risk factors of thrombosis are surgery, trauma, pregnancy, tumor, oral contraceptive as well as genetic risk factors though genetic risk factors were found in about 5% to 10% of cases.” They go on to explain, “Combined oral contraceptives (COCs) are a common method of contraception, but they carry a risk of venous and arterial thrombosis. The association between estrogen-containing oral contraceptives (OCs) and venous thromboembolism (VTE) is well established” (Kim et al. 2013).

Guidelines limit estrogen exposure

Guidelines have been in place for decades to limit a postpartum woman’s exposure to estrogens. According to the CDC’s US Selected Practice Recommendations for Contraceptive Use published in 2016, “Postpartum women should not use combined hormonal contraceptives during the first 3 weeks after delivery because of concerns about increased risk for venous thromboembolism. Postpartum women with other risk factors for venous thromboembolism generally should not use combined hormonal contraceptives 3–6 weeks after delivery.”

The US Medical Eligibility Criteria for Contraceptive Use cites a study examining use of combined hormonal contraceptive (CHC) during the postpartum period and found that VTE rates were higher for the CHC users compared with those not using CHC at all time points postpartum. They also found in studies that the VTE risk is increased during pregnancy and the postpartum period, and that the risk is most pronounced for women in the first 3 weeks after delivery, and it decreases to near baseline levels by 42 days postpartum (US Medical Eligibility Criteria for Contraceptive Use 2018).

In the book, A Midwife’s Handbook, midwife Constance Sinclair discusses guidelines on various forms of contraception. When reviewing the oral contraceptives containing estrogens and progestins, she lists one of the disadvantages for these as creating a hypercoagulability and increasing the risk of thrombophlebitis and pulmonary embolism (Sinclair 2004).

Placenta contains hormones

Placental tissue contains the hormones of pregnancy, which include estrogen and progesterone. Ingesting placenta in raw or pill form introduces a potential source of hormones into your body. Studies on prepared placenta for consumption shows varying levels of estrogens and progestins in placenta tissue, based on preparation and methods.

A 2016 University of Las Vegas (UNLV) study, Presence and Concentration of 17 Hormones in Human Placenta Processed for Encapsulation and Consumption, examined the hormones retained in processed placental tissue. After steaming and dehydration, the most thorough method of processing for encapsulation, they found that estrogens and progestins were retained in the pills at potentially bioactive threshold levels. Their report stated, “To determine whether free (unconjugated) steroid hormones and melatonin in placenta can survive the encapsulation process (namely steaming and dehydration), we analyzed 28 placenta samples processed for encapsulation using liquid chromatography tandemmass spectrometry (LCMS/MS) to evaluate the concentration of 17 hormones” (Young et al. 2016). The results of their study show that “while concentrations of many of the selected hormones are relatively low, mean concentrations of estradiol, progesterone, and allopregnanolone could potentially reach physiological effect thresholds” (Young et al. 2016).

A study published in 2018, Human Placentophagy: Effects of Dehydration and Steaming on Hormones, Metals and Bacteria in Placental Tissue, reported hormone content of raw and processed placenta, and found the highest concentrations of hormones in raw placental tissue. This study reported an 88.2% – 99.6% reduction in hormones in their method of fully processed, steam-dehydrated placenta for encapsulation. However, an increase in progesterone levels was found in the raw-dehydrated method placenta samples. This study reports, “The highest concentrations of hormones were found in raw placental tissue. The hormones were all sensitive to processing. The present study found an enormous hormone reduction through steaming and dehydration of placental tissue. It is most likely caused through denaturation of proteins after thermal processing [47]. Dehydration alone caused a minor hormone loss and even increased the concentration of progesterone” (Johnson et al. 2018).

The preparation methods for placenta ingestion vary widely, with some placenta encapsulators advertising “gentle steaming to retain beneficial hormones and nutrients,” while another popular method is to consume placenta raw in smoothie form over days and weeks postpartum. The 2018 published paper, Placentophagy Among Women Planning Community Births in the United States: Frequency, Rationale, and Associated Neonatal Outcomes, found that midwives are reporting that nearly half of women in their data collection study are consuming raw-dehydrated placenta pills (Benyshek et al. 2018).

Informed Consent

Ingesting placenta in the postpartum period is not a traditional human practice. Research shows that cultural practices universally involve burial or other ceremonial rituals with placenta. With the new trend of placenta ingestion, women should be aware of research on the hormonal content of the placenta and be informed of the potential risk of thromboembolism from ingesting a product that contains hormones including estrogen.

References

Benyshek DC, Cheyney M, Brown J, Bovbjerg ML. (2018). Placentophagy Among Women Planning Community Births in the United States: Frequency, Rationale, and Associated Neonatal Outcomes. Birth 00:1‐10.

Center for Disease Control: US Medical Eligibility Criteria for Contraceptive Use 2018. https://www.cdc.gov/reproductivehealth/contraception/mmwr/mec/appendixd.html Accessed September 2018.

Curtis KM, Jatlaoui TC, Tepper NK, et al. U.S. Selected Practice Recommendations for Contraceptive Use, 2016. MMWR Recomm Rep 2016;65(No. RR-4):1–66. DOI: http://dx.doi.org/10.15585/mmwr.rr6504a1.

Hayes, EH.(2016). Consumption of the Placenta in the Postpartum Period. JOGNN, 45, 78–89.

Jackson E, Curtis KM, Gaffield ME. (2011). Risk of Venous Thromboembolism During the Postpartum Period: a Systematic Review. Obstet Gynecol 117:691–703.

Johnson, S, Groten T., Pastuschek J., Rödel. J., Sammer, U., Markert, U. (2018). Human Placentophagy: Effects of Dehydration and Steaming on Hormones, Metals and Bacteria in Placental Tissue. Placenta 67; 8 – 14.

Kamel H, Navi BB, Sriram N, Hovsepian DA, Devereux RB, Elkind MS. (2014). Risk of a Thrombotic Event After the 6-week Postpartum Period. N Engl J Med 370:1307–15.

Kim, J.-Y., & Kim, Y.-S. (2013). Pulmonary Embolism and Deep Vein Thrombosis Related to Oral Contraceptive Use. Obstetrics & Gynecology Science 56(4), 273–276.

Mayo Clinic https://www.mayoclinic.org/symptoms/blood-clots/basics/causes/sym-20050850 Accessed September 2018.

Petersen JF, Bergholt T, Nielsen AK, Paidas MJ, Løkkegaard EC. (2014). Combined Hormonal Contraception and Risk of Venous Thromboembolism Within the First Year Following Pregnancy. Danish Nationwide Historical Cohort 1995–2009. Thromb Haemost 112:73–8.

Pfeifer, S., et al. (2016). Combined Hormonal Contraception and the Risk of Venous Thromboembolism: a Guideline. Practice Committee of the American Society for Reproductive Medicine. American Society for Reproductive Medicine, Birmingham, Alabama. Published Online: October 25, 2016.

Sinclair, C. (2004). A Midwife’s Handbook. St. Louis, MO: Saunders Publishing.

Sultan AA, Tata LJ, West J, et al. (2013). Risk Factors for First Venous Thromboembolism Around Pregnancy: A Population-Based Cohort Study From the United Kingdom. 121:3953–61.

Sultan AA, West J, Tata LJ, Fleming KM, Nelson-Piercy C, Grainge MJ. (2012). Risk of First Venous Thromboembolism in and Around Pregnancy: A Population-Based Cohort Study. Br J Haematol;156:366–73.

Tepper NK, Boulet SL, Whiteman MK, et al. (2014). Postpartum Venous Thromboembolism: Incidence and Risk Factors. Obstet Gynecol 123:987–96.

Young, S., Gryder, L., Zava, D., Kimball, D., Benyshek, D. (2016). Presence and Concentration of 17 Hormones in Human Placenta Processed for Encapsulation and Consumption. Placenta 43:86‐89.

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“To educate and empower women to breastfeed; to encourage breastfeeding-friendly attitudes, policies, and images in the community; to promote unity among breastfeeding professionals and advocates; and to increase public awareness of the value of breastfeeding.”

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The Sonoma County Breastfeeding Coalition is a community organization formed in 1996. The coalition is supported by volunteer community members comprised of Physicians, Lactation Consultants (IBCLCs), Midwives, Nurses, Dietitians, La Leche League Leaders and breastfeeding supporters representing local WIC agencies, hospitals, health clinics and various community members.