Whether the outcome of the procedure will be natural is not only determined by the shape of the breast implant (round or anatomic), but is a combination of 1) the shape and volume of the own breast, 2) the volume en the diameter of the breast implant and 3) placement of the implant over or under the breast muscle.
With young women with little breast growth the implant will be usually placed under the muscle, but in case of a small compact natural breast sometimes over the muscle. Where breasts have decreased in volume after pregnancy and they start to sag, than a larger volume is required. I prefer to place a larger volume under the muscle (larger breast implants I place preferably under the muscle due to the weight and the risk of sagging breasts long term) but if that fills up the breast insufficiently then I will place the implant over the muscle. Summarized, the volume, diameter of the implant and the position versus the muscle will be set individually for the best result.
Since 1995 I use Eurosilicone round breast implants for all esthetic breast enlargements (there is no financial interest).
Side note: The natural result will be visible after the first weeks/months after surgery. At first the breasts will be slightly swollen and the scars still have to fade. People close to you will not always recognise that, so occasionally you might get well-meant, but premature, critical remarks. Read more about this in the article comments from family and friends.