1 of 2


pla·​cen·​tal plə-ˈsen-tᵊl How to pronounce placental (audio)
: of, relating to, having, or occurring by means of a placenta


2 of 2


: a placental mammal : eutherian

Examples of placental in a Sentence

Recent Examples on the Web
Another Utah lawmaker, the bill’s House of Representatives sponsor, Katy Hall (R), says even before the law was passed, some of Utah’s dozens of stem cell clinics had been dosing patients with placental stem cells. Bymeredith Wadman,, 1 Apr. 2024 The tissue is the contents of the pregnancy, which can include the uterine lining, gestational sac, and fetal and placental remains. Chaunie Brusie, Rn, Parents, 23 Feb. 2024 When a woman is pregnant with just one child, either (or both) of them may become chimeric if their respective cells cross the placental barrier that separates mother and fetus. Cody Cottier, Discover Magazine, 14 Feb. 2024 How placental cells manage to activate only interferon lambda, keeping the immune response simmering but never boiling over, is still a mystery. Annie Melchor, WIRED, 7 Jan. 2024 How placental cells manage to keep the immune response simmering but never boiling over is still a mystery. Annie Melchor, Quanta Magazine, 14 Nov. 2023 In contrast, placental mammals, which give birth to live offspring, have young that start out relatively large. Michael D. D'emic, Scientific American, 1 Sep. 2023 Toppin suggested she get tested for genetic mutations and thrombophilias, an underlying predisposition for the body to form clots that can inhibit placental growth and destroy placental blood vessels. Sadia Rafiquddin, STAT, 31 Aug. 2023 An autopsy by the Maryland Office of the Chief Medical Examiner found a placental infection known as chorioamnionitis and noted that the skin on Onyx’s body had begun to peel — a process that doctors say indicates the death likely occurred at least six hours before delivery. Amy Brittain, Washington Post, 26 Dec. 2023
The early evolution of mammals is a little bit murky, with some placental mammals even likely living alongside dinosaurs and others arising much later. Laura Baisas, Popular Science, 4 Apr. 2024 Like all marsupials, and unlike us placentals, their babies are born even smaller and more helpless than ours and kept in the safety of a pouch. Max Bennett, Discover Magazine, 25 Jan. 2024 Marsupials seem to be substantially different from placental mammals, while primates are different from placentals as a whole. Razib Khan, Discover Magazine, 7 Sep. 2010 People who've had a previous placental abruption, abdominal trauma, preeclampsia, or high blood pressure are most at risk. Rebecca Stewart, Parents, 6 Sep. 2023 Carrying twins also elevates the risks for gestational diabetes (and about half of those affected will later develop Type 2 diabetes), placental abruption, anemia and postpartum hemorrhage. Kwame Anthony Appiah, New York Times, 28 Oct. 2023 The lawsuit states that over the following several hours, Caswell experienced heavy bleeding when her placenta detached from the womb — a serious complication known as placental abruption that can cause severe bleeding and abdominal pain. María Luisa Paúl, Washington Post, 17 Oct. 2023 This study used statistical analysis that showed groups that include primates, rabbits and hares (Lagomorpha), and dogs and cats (Carnivora) evolved just before the K-Pg mass extinction and the impact that the modern lines of today’s placental mammals started to take shape after the asteroid hit. Laura Baisas, Popular Science, 28 Sep. 2023 Testing for Ectopic Pregnancy: How Doctors Make a Diagnosis Placental abruption Less than 1% of pregnant people experience placental abruption,10 typically in the third trimester. Rebecca Stewart, Parents, 6 Sep. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'placental.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use


1785, in the meaning defined at sense 1


1839, in the meaning defined above

Time Traveler
The first known use of placental was in 1785

Dictionary Entries Near placental

Cite this Entry

“Placental.” Dictionary, Merriam-Webster, Accessed 18 Apr. 2024.

Medical Definition


1 of 2 adjective
pla·​cen·​tal -əl How to pronounce placental (audio)
: of, relating to, having, involving, or produced by a placenta
placental lactogen
placental defects
: of or relating to placental mammals


2 of 2 noun
Last Updated: - Updated example sentences
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