Lee Si-young: IVF pregnancy, marathon run, and second child

When a South Korean actress known for action roles and an amateur boxing career announced she was eight months pregnant and planning to run a 10 km marathon, the reaction was a mix of awe and concern. Lee Si‑young didn’t just talk about it—she completed the race with medical clearance and a conditioning coach by her side, then gave birth to her second child a few months later. This article traces her path through IVF, divorce, endurance sport, and the birth of a daughter conceived from a frozen embryo created years earlier.

Born: April 17, 1982 (age 43 as of 2025) ·
Height: 169 cm ·
Known for: Sweet Home, former amateur boxer ·
Marital status: Divorced from Cho Seong‑hyun (2022) ·
Children: Two (son born 2018, daughter born 2025)

Here are the key factual details from Lee Si‑young’s life at a glance.

The implication of the table is that Lee’s career longevity and physical attributes underpin her unique position as an actress who combines athleticism with mainstream fame.

Is Lee Si‑young still married?

Lee Si‑young married restaurateur Cho Seong‑hyun in 2017, and the couple had their first child, a son, the following year. According to the South China Morning Post (Hong Kong‑based news outlet), their divorce was finalized in 2022. No public statement detailed the reason for the separation, and Lee has kept the details of the split private.

Bottom line: Lee Si‑young has been divorced since 2022. She took sole responsibility for the decision to transfer a frozen embryo created during the marriage, a move her ex‑husband did not approve.

Did Lee Si‑young confirm pregnancy through IVF?

Yes. In July 2025, Lee publicly announced that she was pregnant via the transfer of a frozen embryo that had been stored since her marriage. The South China Morning Post reported that the embryo was nearing the end of its allowable storage period when she decided to proceed with implantation. Lee said her ex‑husband did not agree to the transfer and that she accepted full responsibility for the decision. The Straits Times (Singapore mainstream daily) quoted sources confirming that the pregnancy was achieved through IVF, with the embryo having been created during the marriage.

• Lee was 43 years old at the time of the pregnancy announcement.
• She shared the news on social media, later describing the birth of her daughter as “a gift from God” (Korea JoongAng Daily).

Did Lee Si‑young have a second child?

Yes, Lee gave birth to her second child, a daughter, in early November 2025. The Straits Times reported on Nov 5 that Lee announced the birth on Instagram. That same report noted that her first child is a son, born around 2018. The daughter is the child conceived through the IVF transfer described above.

The birth had been widely anticipated after Lee revealed her pregnancy months earlier. She had also completed a 10 km marathon at eight months pregnant, a feat that many followers watched closely.

Did Lee Si‑young run a marathon while pregnant?

Yes, and the timeline is notable. In August 2025, when Lee was seven months pregnant, she said she had received medical clearance from her obstetrician to run and that a conditioning coach would accompany her for a Sydney event (The Korea Times (one of South Korea’s leading English‑language dailies)). On Aug 30 she completed a 5 km race with her son, and the next day she ran a solo 10 km race (Straits Times). A Korean report from Chosun Ilbo described the event as a “first successful family marathon” for Lee and her son. She was eight months pregnant at the time of the 10 km run.

“I have received clearance from my OB/GYN. A conditioning coach will accompany me for the event.” — Lee Si‑young, speaking to The Korea Times, August 2025

Bottom line: Lee completed a 10 km endurance event at eight months pregnant. Whether this is safe depends on individual medical clearance, but Lee’s public disclosure shows an active, medically‑supervised approach.

What is Lee Si‑young’s background?

Lee Si‑young (born Lee Eun‑rae, April 17, 1982) began her acting career in 2008. She gained widespread recognition for roles in Sweet Home (a Netflix horror series) and the hit drama Boys Over Flowers. Beyond acting, she is a former amateur boxer with a competitive record, a detail that underlines her athleticism and fits with her later decision to run a marathon while pregnant. According to her SCMP profile, she has also appeared in The Birth of the Rich and numerous other television projects.

She stands 169 cm tall and has been active in the entertainment industry for over 17 years. Her marital history and children are described above.

Lee’s athletic background—including her amateur boxing career—provides the context for why she felt physically capable of completing a marathon while pregnant.

Timeline: key milestones in Lee Si‑young’s personal life

1. 1982 – Born in South Korea
2. 2008 – Acting debut
3. 2017 – Married Cho Seong‑hyun
4. 2018 – Gives birth to first child (son)
5. 2022 – Divorce finalized
6. July 2025 – Reveals pregnancy via frozen‑embryo IVF; ex‑husband did not consent
7. Aug 30 – 31, 2025 – Runs 5 km (with son) and 10 km (solo) in Sydney at 8 months pregnant
8. Nov 4 – 5, 2025 – Gives birth to daughter; announces on Instagram

The pattern of Lee’s life reveals a woman who consistently defies conventional expectations, from her boxing career to her IVF journey after divorce.

What’s confirmed and what’s not

Quotes from Lee Si‑young

“I took full responsibility for the decision. My ex‑husband did not agree to the embryo transfer.” — Lee Si‑young, as reported by South China Morning Post (July 2025)

“She is a gift from God.” — Lee Si‑young, announcing the birth of her daughter on Instagram, quoted by Korea JoongAng Daily

Summary: what Lee Si‑young’s journey means

Lee Si‑young’s path to a second child was anything but conventional: a divorce, a contested IVF decision, an eight‑months‑pregnant marathon, and a birth announcement that she called a gift. For women in South Korea who face the end of a marriage while still holding stored embryos, her case puts a human face on a legal and ethical tangle. The implication is clear: reproductive autonomy after divorce is still a grey area, and Lee decided to act first and let the debate follow. For single mothers and women navigating fertility choices in Asia, her story is a precedent of determination—and a reminder that the law is still catching up. Lee Si‑young’s actions have forced South Korea to confront the legal vacuum around embryo ownership after divorce.

Frequently asked questions

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• Best Korean Drama 2025 – Singapore Signal
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