Third Blog

🌸 Understanding the Biology Behind Spontaneous Pregnancy Loss (SPL)

When we hear the term spontaneous pregnancy loss, it can sound both clinical and overwhelming. But behind these words lies a biological story—one that involves early development, genetics, and complex body systems. Let’s break down the biological terms that often come up in discussions about SPL, and what they actually mean.

🧬 1. Embryo and Fetus

In early pregnancy, the developing baby is first called an embryo—from fertilization up to 10 weeks of gestation. After that, it’s called a fetus. SPL most often happens in the embryonic stage.

🧪 2. Chromosomal Abnormalities

This is the most common biological cause of early pregnancy loss. Our bodies are built from chromosomes—packages of DNA that carry our genetic blueprint. If there’s an extra, missing, or malformed chromosome in the embryo, development may stop naturally. This is nature’s way of preventing severe problems.

🩸 3. hCG (Human Chorionic Gonadotropin)

This is the "pregnancy hormone." It’s produced by cells around the embryo that help form the placenta. If levels of hCG rise too slowly or start dropping too early, it can signal that the pregnancy isn’t developing properly.

🧠 4. Gestational Sac

One of the first things seen in an early pregnancy ultrasound is the gestational sac—a small, fluid-filled structure that forms in the uterus. If the sac is empty (no embryo visible), it may be what doctors call a blighted ovum, meaning an embryo never developed or stopped developing early.

🔍 5. Subchorionic Hemorrhage

This is bleeding between the uterine wall and the gestational sac. While common and not always dangerous, subchorionic hemorrhages can increase the risk of early pregnancy loss depending on their size and location.

🧫 6. Decidua and Chorion

When a fertilized egg implants in the uterus, the uterine lining transforms into the decidua—which nourishes the embryo. The chorion is a membrane that surrounds the embryo and helps form the placenta. Damage or inflammation in these areas can disrupt pregnancy.

🧬 7. Luteal Phase Defect

This happens when the body doesn’t produce enough progesterone—a hormone needed to support the early stages of pregnancy. Low progesterone can prevent the uterine lining from staying thick enough for the embryo to implant and grow.

⚠️ 8. Threatened, Inevitable, or Missed Abortion

These are medical terms:

Threatened abortion: bleeding but the cervix is still closed—pregnancy may continue.

Inevitable abortion: cervix is open, and pregnancy loss is happening.

Missed abortion: the embryo has stopped growing, but there are no outward symptoms.

🧍‍♀️ 9. Anembryonic Pregnancy

This means the gestational sac developed, but there is no embryo inside. It’s also referred to as a blighted ovum, and it often results from chromosomal issues.

🧠 10. Molar Pregnancy

This rare condition happens when tissue meant to form the placenta grows abnormally. It often contains no viable embryo. A molar pregnancy can lead to serious complications if not treated.

💉 11. D&C (Dilation and Curettage)

This is a procedure sometimes used to remove tissue from the uterus after a pregnancy loss. It helps prevent infection and heavy bleeding.

🕊️ Final Thoughts

Understanding these terms isn’t about memorizing science—it’s about giving language to the loss, making sense of the biology, and perhaps helping the heart to heal just a little. SPL is deeply personal, but knowing the body’s story can be one more step in the journey toward clarity and compassion.