The agency is angry at the fierce bombing by government forces that has resulted in hundreds of casualties, including children. At least 300 patients and medical staff were trapped in the hospital as staff moved patients to safer areas within the hospital, according to SAMS. No one was hurt but the hospital's generator, water tanks and several ambulances were damaged.
"We did a C-section but could not save her, nor her baby", she said.
Turkey fired shells near the advancing columns, which, it says, forced the pro-government fighters into retreat.
Smoke and dust are seen following a reported regime air strike in the rebel-held town of Hamouria, in the besieged Eastern Ghouta region on the outskirts of the capital Damascus on February 21, 2018.
The U.N. chief said he was "deeply saddened by the bad suffering" of civilians in Eastern Ghouta where he said 400,000 people "live in hell on Earth".
Meanwhile, the International Committee of the Red Cross has asked for access to eastern Ghouta, where 1,400 people have been wounded.
The Britain-based Syrian Observatory for Human Rights has also blamed Russian warplanes for the strikes.
It came after more than 100 people were killed on Monday - as Russian forces were blamed for the upsurge in violence by the Observatory. The Syrian government claims that the only civilians who remain in the enclave are being used as human shields by the rebels, the New York Times reports.
"These officials are complicit in the terrorists' crimes against innocent civilians in Damascus and its countryside, as they are denying the Syrian state's right to defend its citizens, fight terrorism, and confront those who fund and arm terrorists."Photos showed children being treated for wounds at a hospital and bodies shrouded in white lined up alongside makeshift graves.
"We no longer have the words to describe children's suffering and our outrage", the United Nations children's agency said.
Minutes later, the airstrikes began. "This is the only thing I can say", said Bilal Abu Salah, 22, whose wife is five months pregnant with their first child. Neighbors came to their rescue and helped them evacuate to the basement, where they spent the night. He said thousands of men, women and children have been deprived of basic health services.
"We in Ghouta have been getting hit by air strikes for more than 5 years and this is not new to us but we have never seen anything like this escalation".
The Observatory said numerous planes over Ghouta appear to be Russian.
At least 38 people died on Wednesday.
A doctor from Damascus told Al Jazeera that residential areas, schools and markets had been bombed.
A wounded Syrian sits on a gurney as victims pour into a makeshift hospital in the rebel-held town of Douma, following air strikes by regime forces on the besieged Eastern Ghouta region.