Galway Fertility: IVF Embryo Success from Bed of Nails

Written by The Blue Heron Clinic

Newborns conceived through IVF may owe their existence to the fact that they spent their first few days resting on a bed of nails – according to a publication from New Scientist.

In vitro fertilisation takes place iin a medically controlled enviornment where after a few days of culturing, a fertilised egg is implanted into a woman's uterus. "But, clearly, a dish is an unnatural environment for a fertilised egg to spend its first days, says Gary Smith at the University of Michigan, Ann Arbor."

"The idea is to ask how embryos develop in the body and copy that in the laboratory," he says. His team has focused on mimicking the pulses of nutrient-rich fluid sent washing over the embryo by muscle contractions within the fallopian tubes.

To do this a plastic chip containing a small well was used to house the embryo. The bottom of the well sits on a complex network of

30-micrometre-deep channels filled with a nutrient and hormone-rich medium.

Below these channels is a flexible polymer construct, and under this an array of moveable pins taken from an electronic braille display. The pins can be manipulated in an upward or downward motion, pushing up the flexible polymer and squeezing the channels to send pulses of nutrient rich medium washing over the embryo.

Smith's team also recruited 25 women who were undergoing IVF treatment. Each woman produced between eight and 20 eggs that were fertilised in the fertility lab. The group then placed roughly half of the 300 or so embryos in the new nutrient system to culture, and half in the traditional static IVF system.

Two days later, the group examined  markers of embryo quality, such as the number of cells. The results suggest that the new system boosts embryo quality: 39 per cent of embryos cultured this way were graded as top quality compared with 29 per cent of those in a dish. The team also found that a zygote's chance of developing into a good quality embryo - a step below top quality but still suitable for implantation - was 1.6 times higher if it had been cultured on a bed of pins.

The best quality embryos from both systems were implanted into the women, some of whom went on to have successful pregnancies, which were not tracked. "The general consensus is that this system will translate into better pregnancy rates, but we need to study these [pregnancies] before recommending the system," says Smith, who presented the findings at the European Society of Human Reproduction and Embryology annual meeting in Stockholm, Sweden, this month.

The moving pins may be crucial, says Michele Boiani, an embryologist at the Max Planck Institute for Molecular Biomedicine in Münster, Germany. Boiani recalls once driving a number of mouse embryos to another lab. "The 'highway mouse embryos' developed better than the ones I had left as controls in the static incubator," he says.