10/01/2026
“I’m three days overdue and I’ve been told I need to be induced because my placenta is calcifying, and that means it’s dying.”
I have been receiving that message for years. It is the number one search that brings people to my website. You can read my blogpost When not to induce – reason #408 – a placenta with calcium deposits where I unpack this.
Read it at https://billieharrigan.com/blog/2018/10/18/when-not-to-induce-reason-408-a-calcified-placenta
To begin, the placenta is your baby’s organ made of the same genetic material as the baby. It grows and matures alongside the baby, fed by the same maternal nutrition as the baby. It’s responsible for nutrient exchange, filtering, and chemical signaling.
Because we love to put numbers on things, placentas are given “grades” when examined through an ultrasound:
- Grade 0 means under 18 weeks
- Grade I from 18 to 29 weeks
- Grade II from 30 to 38 weeks
- Grade III from 39 weeks until birth
- Grade III is not an expiration, it’s merely what a placenta is supposed to look like when the baby is at term.
A healthy placenta develops calcium deposits at term in the same way a healthy person develops a few gray hairs as they age. Wrinkles are not a sign of imminent death.
So where did the fear come from? From studying preterm babies who were already compromised, whose placentas showed heavy calcification early. That finding then got applied to healthy women at 40 weeks, which is not what the research says at all. A study of over a thousand pregnancies found the dividing line is 32 weeks: significant calcification before 32 weeks was associated with real problems, and after 32 weeks there were no increases in adverse outcomes — even in mothers with diabetes, high blood pressure or a smoking history.
One more. Those granular bumps you can see and feel on a placenta after it is born are not calcium deposits. They are infarcts — deposits of fibrin where some cells have died. These are very common in healthy full-term pregnancies and have no clinical significance.
Make wise choices, my friends.
The Hello October newsletter goes out on the 1st, and next month’s research rant is one you will not want to miss. Get on the list at www.billieharrigan.com so it lands in your inbox.
𝗦𝗼𝘂𝗿𝗰𝗲𝘀:
Chen, K. H., Chen, L. R., & Lee, Y. H. (2011). Exploring the relationship between preterm placental calcification and adverse maternal and fetal outcome. Ultrasound in Obstetrics & Gynecology, 37(3), 328-334.
Chen, K. H., Chen, L. R., & Lee, Y. H. (2012). The role of preterm placental calcification in high-risk pregnancy as a predictor of poor uteroplacental blood flow and adverse pregnancy outcome. Ultrasound in medicine & biology, 38(6), 1011-1018.