<Tr> <Td> Caesarean section </Td> <Td> 1.56 </Td> <Td> 1.51--1.60 </Td> </Tr> <Tr> <Td> gestational diabetes </Td> <Td> 1.48 </Td> <Td> 1.33--1.66 </Td> </Tr> <Tr> <Td> induction of labour </Td> <Td> 1.18 </Td> <Td> 1.10--1.28 </Td> </Tr> <Tr> <Td> small for gestational age </Td> <Td> 1.39 </Td> <Td> 1.27--1.53 </Td> </Tr>

What was the purpose of test tube b