Harrowing reports of babies stolen at birth and human organ removal in an Ukrainian city are to be investigated by a top European political body.
The mothers of the babies were said to be all in excellent health
The Council of Europe's Parliamentary Assembly is sending a rapporteur to Kharkiv as Ukraine's prosecutors delve into the cases of three mothers.
"People are afraid to even give birth now," Kharkiv campaigner Tatyana Zakharova told the BBC News website.
The main hospital under scrutiny has dismissed accusations against it.
Ruth-Gaby Vermot-Mangold, the Parliamentary Assembly of the Council of Europe (Pace) rapporteur, is to visit Maternity Hospital No 6 after her arrival on Monday and will meet local parents, Ms Zakharova and Ukrainian officials.
Her trip will also take her to the capital, Kiev, amid reports that babies may have been snatched at birth in other Ukrainian cities.
The alleged baby thefts go back to the autumn of 2002 but the case achieved wider publicity last year after MPs from across Europe tabled a motion at the Pace, which brings together 46 countries.
Underlining real concern over baby-trafficking from Eastern Europe, they pointed to newspaper adverts in Moldova encouraging single mothers there to sell a child for 3,000 euros.
"There has been no concrete follow-up in these [Kharkiv] cases," Agnes Nollinger, who is accompanying Ms Vermot-Mangold, told the BBC News website on Friday.
Prosecutors are still investigating the three cases, nearly three years after Svetlana Puzikova arrived in labour at the maternity hospital in the early hours of a November morning.
She was in her 40th week and her family were waiting to visit the new mother and child later in the day.
Only the midwife and one other woman who was not introduced to her were at hand for the birth, Tatyana Zakharova of the National Ukrainian Federation of Multiple-child Families (NUFMF) told the BBC.
The last she saw of her baby was it being passed to the stranger. After that, 20 kilos lighter after her delivery, she and her family were told it had died at birth.
According to the NUFMF, doctors' records indicated the birth of a healthy child was to be expected.
No birth or death certificates were issued as an "abortion" had occurred, and the family was told that the remains of Svetlana's baby had been consigned to a communal grave with 27 other foetuses as "bio waste".
When the family demanded an inquest, this grave was reopened the following year in the thaw of the harsh Ukrainian winter.
Inside, the NUFMF reports, were 30 sets of remains, not 28, and Svetlana's baby could not be identified among them.
In late December 2002, Lena Zakharova (no relation to Tatyana) should have given birth to her first baby at Maternity Hospital No 6. It, too, was declared dead.
A third mother, Tatyana Dormidontova, gave birth at a maternity ward of another Kharkiv hospital in her 32nd week of pregnancy in July 2001.
Her baby was declared dead but the body was reportedly that of a much bigger baby. The mother herself died soon after birth.
All three women, according to Tatyana Zakharova, were first-time mums and each was in excellent health.
This factor leads her to suspect the babies may have been stolen for illegal adoption or, even worse, for the use of their organs.
There are reports that the babies' parents - or in Dormidontova's case the grandparents - were asked to sign blank pieces of paper. In their confused and fraught state they did not refuse.
The remains in the grave had allegedly had their organs and brains removed.
"They were like gutted rabbits," Tatyana Zakharova told the BBC.
Larissa Nazarenko, head of Maternity Hospital No 6, was quoted as saying by the Associated Press news agency that "not a single fact" had been proven.
The Council of Europe team will be in Ukraine until Thursday to compile a report that will then be handed to the Parliamentary Assembly.