Introduction

Miscarriage, or early pregnancy loss, is one of the most difficult and emotionally charged experiences a woman or couple can go through. Affecting approximately 10–20% of known pregnancies, miscarriage can occur for a variety of medical reasons, many of which are not within the control of the mother. While often surrounded by silence and stigma, understanding why miscarriage happens can offer clarity, healing, and help in planning for future pregnancies.

At Second Spring Women’s Clinic in Gangnam, Seoul, we believe in combining cutting-edge diagnostics with compassionate care. Led by renowned OB-GYN Dr. Seon-Hwa Jeong, we support women experiencing miscarriage with personalized evaluations and evidence-based treatment options. By exploring the five most common medical reasons for miscarriage, this article aims to educate and empower women on their reproductive health journey.

Chromosomal Abnormalities — The Leading Cause of Miscarriage

One of the most common causes of miscarriage, especially in the first trimester, is chromosomal abnormalities. These errors typically occur during fertilization, when sperm and egg meet to form a new embryo. If the resulting embryo has too many or too few chromosomes, it may not be viable, leading to an early pregnancy loss.

Chromosomal abnormalities account for more than 50% of miscarriages in the first 12 weeks of pregnancy. These errors are usually random and not inherited, meaning they don’t necessarily indicate a problem with either parent’s health. Conditions such as trisomy (e.g., Down syndrome), monosomy, or triploidy can disrupt fetal development and result in the pregnancy ending naturally.

While chromosomal testing isn't routinely done after a single miscarriage, it may be considered after recurrent losses. Second Spring Women’s Clinic offers genetic testing and karyotyping services to couples dealing with multiple miscarriages, helping to identify underlying genetic risks and offer solutions such as preimplantation genetic testing (PGT) during IVF.

It’s important to note that chromosomal miscarriages are not preventable—but they are also not the result of anything a woman did wrong. Offering emotional support and clear medical insight, our clinic guides patients through both the grief and next steps with sensitivity.