Hi Honey. First let me say that you don't have to have an anxiety disorder to be afraid for your baby. I do not have a disorder and I am terrified of SIDS. I did a great deal of research on the subject and here is what I found. (I am going to quote several sites)...
From AAP Websitehttp://www.aap.org/new/sids/reduceth.htm
What Is SIDS?
Sudden Infant Death Syndrome (SIDS) is the sudden and unexplained death of an infant under one year of age.
SIDS, sometimes known as crib death, is the major cause of death in babies from 1 month to 1 year of age. Most SIDS deaths occur when a baby is between 1 and 4 months old.
. More boys than girls are victims, and most deaths occur during the fall, winter and early spring months.
The death is sudden and unpredictable; in most cases, the baby seems healthy. Death occurs quickly, usually during a sleep time.
From The National SIDS Resource Centerhttp://www.sidscenter.org/SIDSFACT.HTM
What Are the Most Common Characteristics of SIDS?
Most researchers now believe that babies who die of SIDS are born with one or more conditions that make them especially vulnerable to stresses that occur in the normal life of an infant, including both internal and external influences. SIDS occurs in all types of families and is largely indifferent to race or socioeconomic level. SIDS is unexpected, usually occurring in otherwise apparently healthy infants from 1 month to 1 year of age. Most deaths from SIDS occur by the end of the sixth month, with the greatest number taking place between 2 and 4 months of age.
A SIDS death occurs quickly and is often associated with sleep, with no signs of suffering. More deaths are reported in the fall and winter (in both the Northern and Southern Hemispheres) and there is a 60- to 40-percent male-to-female ratio. A death is diagnosed as SIDS only after all other alternatives have been eliminated: SIDS is a diagnosis of exclusion
From Think Twice Global Vaccine Institutehttp://thinktwice.com/sids.htm
Sudden Infant Death Syndrome
Is There a Link?
A study published in the Journal of the American Medical Association found that children diagnosed with asthma (a respiratory ailment not unlike SIDS) were five times more likely than not to have received pertussis vaccine.(1) Another study found that babies die at a rate eight times greater than normal within three days after getting a DPT shot.(2) The three primary doses of DPT are given at two months, four months, and six months. About 85 percent of SIDS cases occur at one through six months, with the peak incidence at age two to four months.
These are just a few of the websites that you can go to and get a great deal of facts on SIDS. The peak ages are from 2 months to 4 months, but anytime between 1 month and 6 months. I think that SIDS cases after 6 months are not unheard of, but not very common either.