C.I.O. is the most famous sleep training technique, and the most controversial — although, despite its daunting name, it is safe and effective. In its simplest form, unmodified extinction, you place your infant down at bedtime, drowsy but awake, and then leave the room, without returning to check on or soothe your baby. This method will work quickly, but often produces prolonged periods of crying for a few nights, which can be difficult for parents to tolerate.
Thank you for checking out The Baby Sleep Site! I’m sorry to hear you’re having so much trouble with sleep. Based on your comment, it does sound like your little one might be coming into the 4 month sleep regression. We have an article with a lot of information on that here: https://www.babysleepsite.com/baby-sleep-patterns/4-month-sleep-regression/
If your baby is growing poorly or is difficult to console, you should talk to your child’s pediatrician to ensure that your child’s sleeping difficulties have no medical cause. Likewise, if you are struggling with depression, it is critical to discuss this with your child’s pediatrician as well as your own physician. Poor sleep can prolong postpartum depression in mothers.
A version of this technique called graduated extinction was popularized by Dr. Richard Ferber in his book “Solve Your Child’s Sleep Problems.” Here, parents check on their child at set intervals. Checks should be brief and to the point: Picking up your child, spending too much time hovering over the crib or otherwise offering more contact than a quick soothing word can be counterproductive. Some babies find these brief checks soothing and will go to sleep more quickly. Others will redouble their crying as soon as their parents leave the room. Parents need to make a judgement about whether or not checking in is helping their baby through this process. If you decide to use checks, I would recommend checking no more than every five minutes and resisting the temptation to check if your child seems to be calming down.
No one likes to talk about sudden infant death syndrome (SIDS); it is a terrifying topic. SIDS is defined as the sudden death of an infant, which remains unexplained after a thorough investigation. These deaths occur in the first year of life, with the highest risk occurring between 2 and 6 months of age. Fortunately, these deaths are becoming less common, thanks in large part to the early ’90s Back to Sleep campaign, which urged parents to place infants to sleep on their backs. Suffocation is also a major risk for infants if they do not sleep in a safe sleeping environment.
Some of these experts think cry it out methods are not good for babies. Pediatrician and "attachment parenting" advocate William Sears devotes an entire chapter of The Baby Sleep Book to a critique of cry it out approaches. Sears, along with no tears advocates such as Elizabeth Pantley (author of The No-Cry Sleep Solution), believes that cry it out techniques can give your child negative associations with bedtime and sleep that could last a lifetime.
Parents are often hesitant to go this route, worried about how much crying will be involved. While McGinn doesn’t deny it can be difficult at first, she finds parents are often surprised by how quickly it works. “Yes, there is a lot of crying, but it’s short term,” she says. “You might get a lot of crying for two to three nights, but then every night is less and less.” She says you should see significant improvement with this method by night three or four but adds that it’s important to try it for a week before determining that it’s not working.