单选题 The idea of test-tube babies may make you starry-eyed with delight at the wonders of modern medicine or bleary-eyed with considering the moral/legal implications of starting life in a laboratory. But if you've ever been pregnant(怀孕的)yourself, one thing is certain: You wonder what it's like to carry a test-tube baby. Are these pregnancies normal? Are the babies normal?
The earliest answers come from Australia, where a group of medical experts at the Queen Victoria Medical Center in Melbourne have taken a look at the continent's first nine successful test-tube pregnancies. The Australians report that the pregnancies themselves seemed to proceed according to plan, but at birth some unusual trends did show up. Seven of the nine babies turned out to be girls. Six of the nine were delivered by Caesarean section(剖腹产术). And one baby, a twin, was born with a serious heart defect and a few days later developed life-threatening abdominal(腹剖的)problems.
What does it all mean? Even the doctors don't know for sure, because the numbers are so small. The proportion of girls to boys is high, but until there are many more test-tube babies, no one will know whether that's pure coincidence(巧合)or something special. The same thing is true of the single heart defect; it usually shows up in only 15 out of 60,000 births in that part of Australia, but the fact that it occurred in one out of nine test-tube babies does not necessarily mean that they are at special risk. One thing the doctors can explain is the high number of Caesareans.
The Australian researchers report that they are quite encouraged. All the babies are now making normal progress--even the twin with the birth defects.