 Which factor is the best predictor of necessity for an emergency C-section on a fetus?
Obstetrics for beginners It's my first go at delivering a baby by caesarean section – and the foetal head is impacted, jammed in its mother's pelvis. Incisions have been made in the lower part of the mother's abdomen and womb. I've pushed my gloved hand inside and managed to slide my fingers between the baby's head and the surrounding uterine tissue. The baby is tightly wedged in. The baby's mother – she's called Debra – remains impassive throughout these agonised fumblings. Debra – Desperate Debra to use her full trade name – is a simulator designed to help doctors practise their skill at dealing with impacted foetuses: babies that get stuck trying to exit the womb by the normal route. She comprises the lower two thirds (ie from the mid-chest region downwards) of a life-sized but limbless female torso made of flesh-coloured silicone rubber. She comes with a vulva, a pre-cut incision in her abdomen and, most importantly, a uterus containing a foetal head that should, in the normal way of things, be free to emerge between her legs. But this fetus is going nowhere until an obstetrician – or in this case me – can successfully grasp and pull it out. The clever and sophisticated simulator I'm playing with started life as a lash-up in an obstetrician's home workshop: a Heath Robinson-style contraption barely recognisable as a model of the human body. But it wasn't at that stage intended as a simulator for training medical staff. Its sole purpose was to test the effectiveness of a novel device called a Tydeman tube. Paradoxically, although the testing equipment, Debra, is now commercially available, the device it was intended to test has yet to reach the market. The inventor of the tube and of Desperate Debra is Dr Graham Tydeman, a consultant in obstetrics and gynaecology at Victoria Hospital in Kirkcaldy, Fife. Only after he'd built Debra did he realise that she might serve a purpose beyond his original intention. His is a decade-long tale of inspired insights, thwarted aims and shifting purposes; but with a good outcome. Although the Tydeman tube is still in gestation, Desperate Debra herself is now thriving. To understand the desperation of Debra and how the Tydeman tube might help to relieve it requires a brief foray into basic obstetric knowhow. Evolution has endowed us with heads proportionally so large that even when labour runs according to plan, the delivery process involves a bit of a squeeze.
 There is no agreed upon factor
 Father's birth weight  Mother's birth weight  Practitioner's level of experience  There is no agreed upon factor