The list of more than 1,000 additions also includes the term 'me time', when an individual devotes time to doing what they want in order to relax, and hangry, used when someone is "bad-tempered or irritable as a result of hunger".
To qualify for the list the OED requires several independent examples of a word being used and evidence that it has been in use "for a reasonable amount of time".
Researchers often consult experts in a particular field when deciding if a new coinage should be included in the renowned guide of more than 829,000 words, senses and compounds.
In the latest update the team also spoke to contributors to the online parenting forum Mumsnet, in an effort to capture the developments in the English language that have risen around childbirth.
Among the new entries resulting from the project are a number of initialisms commonly used online, such as TTC (trying to conceive).
When taking a pregnancy test one might get a BFN (big fat negative) or a BFP (big fat positive), while further down the line parents may try CIO (cry it out) as a means of baby sleep training.
OED Senior Editor Fi Mooring said: "These words reflect personal experiences but many of them also resonate much more widely, even with people who are not parents.
"The distinctive lexicon of parenting maps a whole range of human experience, from immense joy to immeasurable sorrow and, considering its relevance to so much of the population it seemed an underrepresented category of vocabulary in the Dictionary."
Researchers also traced the use of mansplain to a web forum in an exchange between a man and a woman in 2008.
The verb is typically attributed to a man explaining something "needlessly, overbearingly, or condescendingly, especially to a woman, in a manner thought to reveal a patronising or chauvinistic attitude".
The term snowflake has taken on a less than complimentary meaning as a noun in recent times, especially on social media, earning it a new sense.
Now used as an insult to describe someone who is "overly sensitive or as feeling entitled to special treatment or consideration", the word in fact once had positive connotations and was used to describe children with a unique personality and potential.
Ransomware is also among the new additions - less than a year since the NHS was one of a number of global institutions to fall victim to the WannaCry cyber attack that was carried out with the use of malicious software.
In May 2017 virus - blamed on North Korea - locked up computers and demanded a sum of money to release the files, causing massive disruption.