When a group of Syrians crossed from Greece into Macedonia one day earlier this summer, several of them picked a few grapes in a vineyard just north of the border. Most spat out the fruit immediately: the grapes weren’t ripe. But Fattemah Abu al-Rouse kept chewing. “The grapes are sour,” Fattemah later explains. “And as a pregnant woman, I needed that to make me feel less nauseous.”

More than 300,000 people have risked the sea journey from Turkey to Greece so far this year, and the majority have subsequently walked and bussed their way through Macedonia, Serbia and Hungary to the countries of northern Europe. Little exemplifies their desperation more than the fact that many of them are, like Fattemah, doing so while pregnant.

It is impossible to calculate exactly how many refugees are expecting children. But at every border crossing along the route, pregnant women are a common sight. According to the UN refugee agency, women form 13% of those arriving in Europe this year. Doctors who treat them as they walk through the continent estimate that, in ball-park terms, more than a fifth of that total might be pregnant.

“It’s really a lot,” says Nevena Radovanovic, a doctor with Médecins sans Frontières, which runs several mobile clinics for refugees throughout the Balkans, and collects information about the health of those on the move. “Out of 100 women, maybe 20 or 30% are pregnant – usually around five months’ pregnant. But we also see women who are nine months’ pregnant or will deliver in two days. And there is nothing you can say to them that will convert them to not going.” One woman treated by Radovanovic’s colleagues gave birth in Macedonia.

Fattemah cries when she tries to explain what motivates a mother-to-be to cross the sea in a flimsy rubber boat, and then spend weeks walking and bussing to Scandinavia. It was a Hobson’s choice, she says. Either she braved the journey, and risked losing her unborn son. Or she stayed put, forcing both the baby and his one-year-old elder brother, Hammouda, to grow up either in a warzone or in poverty.

A father with his pregnant wife and his daughter asks for permission to enter Hungary. Photograph: Attila Kisbenedek/AFP/Getty Images

If Fattemah hadn’t taken a chance on Europe, Hammouda’s future would have been either in the ruined Damascus suburb of Yarmouk, where her home was destroyed in a bomb attack, or in the limbo of Turkey, where neither she nor her husband have the right as refugees to work legally.

“I didn’t ever expect that I would have the [unborn] baby,” Fattemah, a teacher, says of her choice. “I thought maybe I will lose one baby but save another one: Hammouda. I thought: I can provide a good life for Hammouda, so it’s worth it.”

Four months pregnant when she set out, for much of the journey Fattemah thought the baby was dead. She didn’t tell her husband Nasser, an interior designer. But while they were on the road she didn’t feel the baby move once, leading her privately to conclude that the exertions of the journey had caused a miscarriage.

The tiny Greek island sinking under Europe’s refugee crisis – video Guardian

And the exertions were many. For a start, there was the hunger and thirst. Throughout the journey, Fattemah did not have enough to eat or drink – a dangerous situation for any pregnant woman, and doubly so for one who has to walk several miles a day. This problem was particularly pronounced in the period after the seven-hour sea crossing (during which their boat nearly sank), when the family still had to walk 16 hours through the island of Samos to find shelter, water, and food.

Later, Fattemah collapsed. She was taken to a hospital in the nick of time, where doctors told her that something had gone wrong with the waters in her uterus. “They told me: it’s good you came,” she remembers. “Because otherwise it would have been so dangerous for the baby.”

Walking in fits and starts through the Balkans was exhausting. Carrying the weight of her unborn son, Fattemah frequently experienced excruciating pain in her stomach and lower back – a common malady among pregnant women making this journey, says Radovanovic.

In Greece, Fattemah also experienced a spasm in her leg, while her whole predicament was exacerbated by frequent nausea; an inability to control her bladder; and by the trauma of having to sleep in the street. On her first night in Macedonia, she slept on a black binliner, while the family waited outside a police station for travel documents. “This isn’t great for a pregnant woman who needs to be in a warm soft place, not on a cold hard floor,” says Fattemah.

Eventually the trauma became so great that she stopped caring about the possibility of being attacked and robbed by thieves – a common fear among Syrian refugees, particularly during the early part of the summer.

“Sometimes I just wanted to sit down because I couldn’t take it anymore,” Fattemah says of the days she spent walking in remote countryside. “I wasn’t afraid of the gangs who might come and take my money. But I cried several times because of the pain and because I had to sleep in the street.”

All the while, Fattemah’s baby lay motionless inside her womb, meaning that when she, Nasser and Hammouda finally arrived in Sweden, she still did not know whether her unborn son was dead or alive. “So the first thing we did was go to hospital to check if the baby was alive,” she remembers. “And then we heard its heartbeat.”