At 3 am on April 24, 2010, a baby boy was delivered in a field hospital after a four-hour operation.

He didn't cry and his breathing was shallow. His face was covered in blood and his mouth was filled with meconium - an intestinal discharge that can block a baby's airways if breathed in prior to birth.

Obstetrician Zhang Hong-juan performed artificial respiration on the newborn immediately, ignoring shouted warnings from a midwife.

"Doctor Zhang, this is a high incidence area for infectious diseases. The baby has blood all over its face. You want to get killed?" midwife Cui Xinmiao shouted.

After two minutes, the baby's cries rang out in the field ward, but the doctor had fainted.

The scene occurred in a field hospital set up by Jinan Military Region personnel in the Yushu Tibetan autonomous prefecture of Qinghai province, which was hit by a 7.1-magnitude earthquake on April 14, 2010. The tremor left more than 2,000 people dead and more than 8,000 injured.

The baby's mother Karcho had been pregnant three times before but all three babies died from labor complications.

When Karcho was received at the hospital, Zhang had just returned to her dormitory 10 kilometers away after a full day's work. As the only obstetrician at the field hospital, she was called back in.

Karcho's newborn is just one of 73 babies Zhang delivered in her 62 days' stay in Yushu. During that time, she also carried out 27 gynecological operations and treated more than 2,000 patients.

Zhang left Yushu almost four years ago, but the obstetrician still keeps in close contact with the quake-hit area.

She has revisited Yushu three times, searching for the children she delivered.

"It was my first time to have direct contact with Tibetans after I went to Yushu and I felt that the life of the locals is very hard," Zhang said.

"Many houses collapsed and parents couldn't even prepare clothes for their babies before they went to the field hospital.

"I am a mother myself and could feel their difficulties. I am very worried whether those children can grow up healthy in those conditions.

"This makes me go back to Yushu to see them every year."

Many of the parents are herdsmen and do not live in fixed locations in a region where the population is widely scattered. But with the help of Sonam Pachug, a pediatrician at Yushu People's Hospital, Zhang has located 33 of the children she helped deliver.

He helped to locate Lhachug Jungyul, the first child Zhang delivered in Yushu and who she named. The name means "the People's Liberation Army came to help Yushu after the quake".

On the plateau at an altitude of 4,500 meters, Zhang and Sonam Pachug traveled almost 200 kilometers on a mountain road to reach the child last year.

On May 18, Chimed Tobden, a boy delivered by Zhang, his father Karu, and his uncle Trinley traveled from Yushu to Zhengzhou, the capital of Henan province where Zhang is based, to thank her.

Four years ago, the boy's mother Ashe had tried to deliver Chimed Tobden at home for three days but failed. The family then turned to Zhang, who delivered Chimed Tobden by cesarean section.

"Doctor Zhang also has sent many gifts to Chimed Tobden in the last four years, including some toys, clothes and educational material," Trinley said.

"When Chimed Tobden grows up, we will tell him that all those gifts are from Dr Zhang, our savior."

houliqiang@chinadaily.com.cn