About one in three women experiences spotting or light bleeding during early pregnancy, which is a common occurrence. Such vaginal bleeding in the early stages is often perceived as a sign of miscarriage. Is that really the case? In fact, most of the time, it isn't.

“About one-third of women experience bleeding in the early stages of pregnancy,” said Dr. Yoo Jung-hyun, head of the Obstetrics and Gynecology Department at Bundang Jesaeng Hospital, on the Korean Doctors Weekly YouTube channel “I Am a Doctor.” “It's easy to immediately think that spotting means a miscarriage, but that's not necessarily the case.”

There is a reason why spotting or blood clots occur so frequently in about one-third of women in early pregnancy. That’s because bleeding inevitably occurs during the process of the fertilized egg implanting.

“As the fertilized egg burrows into the uterine lining, nerves and blood vessels connect. This isn't like snapping pipes together; it involves creating blood vessels and blood cells as they connect. Naturally, blood leaks during this process,” Dr. Yoo explained.

The color of this blood varies, depending on the amount and timing of the bleeding during implantation, appearing as red, pink, bright red, black, or brown.

“If the bleeding is fresh, it will be slightly red. If the amount is small, it will be pink. If the amount is large, it will be bright red. If it has pooled inside and then comes out when moving or straining the abdomen, it will be black if the amount is large and brown if the amount is small,” Yoo said.

Some women experience spotting even after the first trimester, once implantation is complete. This bleeding isn't necessarily a sign of miscarriage either.

“After implantation, the lower part of the uterus expands significantly around the fourth to fifth month of pregnancy,” Dr. Yoo said. “While the entire uterus stretches, the slightly narrowed area just above the cervix expands particularly. Women whose placenta was attached slightly to this area may experience bleeding from that spot as the uterus stretches.”

In other words, women whose placenta forms slightly lower in the uterus are more prone to bleeding around the fourth month of pregnancy. This type of bleeding typically lasts for about a month before stopping.

So, how should women in early pregnancy handle such bleeding?

Dr. Yoo advised, “You must go to the hospital to determine whether it's unavoidable bleeding or bleeding caused by another underlying issue,” recommending a visit to an obstetrics and gynecology hospital.”

For this reason, when patients visit the hospital, doctors perform a pelvic exam and ultrasound, Yoo said. She pointed out that the reason for the pelvic exam is to check for polyps. Some polyps, hidden in the cervix near the uterine opening, may protrude outward as the uterus enlarges. In other cases, a polyp may detach during implantation, causing bleeding.

Bleeding caused by polyps can recur throughout pregnancy but usually resolves after delivery, and the bleeding volume is typically not heavy. While the internal exam aims to confirm the presence of polyps, the ultrasound assesses the fetus's condition and evaluates the extent of blood pooling between the endometrium and the placenta during implantation, Dr. Yoo explained.

“If the blood pools in the upper part of the uterus, it's farther from the vagina and won't flow out easily. If it pools in the lower part, it will flow out with movement,” Yoo said. “For that, the doctor will prescribe medication.”

Of course, spotting in early pregnancy can sometimes signal a miscarriage.

“Bleeding related to miscarriage is typically heavy (about the amount of bleeding on the second to third day of a period) and causes abdominal pain as the uterus contracts,” Dr. Yoo said, recommending visiting one’s regular OB/GYN hospital for an examination if such bleeding occurs.