It isn't illegal to chew gum, but it is illegal to bring them into Singapore or sell them except for medical purposes. Since you can't buy gum (selling is illegal) there's no way to chew them so it's almost as good as not being able to chew gum. See this: http://www.customs.gov.sg/leftNa...
Definition: In Vitro. A study done in vitro, in contrast, looks at how a drug or procedure responds in the confines of a test tube or laboratory dish. Clinical trials or medical studies may be performed either in vivo or in vitro.
In Vitro Fertilization: IVF. In Vitro Fertilization (IVF): Side Effects and Risks. In Vitro Fertilization is a one assisted reproductive technology (ART) commonly referred to as IVF. IVF is the process of fertilization by manually combining an egg and sperm in a laboratory dish, and then transferring the embryo to the uterus.