Segulos for preventing crib death:

Not to nurse the child:[1] A woman of whom it has been established by doctors that her milk is poisonous and is damaging to her child, then she is not a nurse her child and is rather to hire a wetnurse. [Indeed, there was once a woman who came to a Tzadik and Rebbe crying before him that both of her sons were born mute, and he told her that she should stop nursing her children as it is her milk which is causing this to happen.[2]]

To move to a different country:[3] A person who has had a few of his children pass away, is to move to a different country, as it could be that the country causes the death.

To sell the child:[4] A person who has had a few of his children pass away, is to sell his child to his friend for a small amount of money or food. This is done by the father being given money or food from an individual and in exchange the individual is considered to have purchased the child.

Naming after the deceased child:[5] The following Segula was given by the famous Gaon of Vilna to his daughter who had a child pass away shortly after birth. He instructed that the child that is born after the child that passed away should be named after him, with another additional name, preceding the newer name to the name of the sibling. For example, if the name of the child who died was Reuven, then the next child should be called Shimon Reuven. Indeed, the daughter of the Gaon of Vilna had a son named Dovber who passed away, and based on the advice of her father named her second son Zalman Ber, and he lived a full life. This tradition has been followed by many and their other children have lived.

Garbing the child in a pure linen garment:[6] A father who has had a number of children pass away due to Lilith or the evil spirit is to garb his newborn child with only linen garments. If the linen garment has even a single threat of another material, then it is not to be used.

[1] Chacham Tzevi 64; Chasam Sofer E.H. 136; Shemiras Hanefesh 18; Kaf Hachaim 116:136

[2] Shemiras Hanefesh 18; Kaf Hachaim 116:136

[3] Sefer Chassidim 246; Kaf Hachaim 116:137; Sefer Shemiras Haguf Vihanefesh [Lerner] 199:1

[4] Sefer Chassidim 245; Shemiras Hanefesh 179; Kaf Hachaim 116:137; Sefer Shemiras Haguf Vihanefesh [Lerner] 199:2

[5] Zivcheiy Tzedek 116:83; Rav Dovid Luria in Aliyos Eliyahu 51; Kaf Hachaim 116:135

[6] Pischeiy Teshuvah 352:2; Yalkut HaReuveini Parshas Mikeitz; Kaf Hachaim 116:138