Let us first understand what is new born According to WHO

"A newborn infant, or neonate, is a child under 28 days of age. "
A child born before the expected date is said to be pre-term , born on the expected date is said to be full-term and born after the expected date is said to be post-term but all these babies are newborn .

Now let us understand what is an insurance :

An insurance policy is a legal contract between the insurance company (the insurer) and the person(s), business, or entity being insured (the insured).

There are four basic parts to an insurance contract :

The Declaration Page
This page is usually the first part of an insurance policy. It identifies who is the insured, what risks or property are covered, the policy limits, and the policy period (i.e. time the policy is in force).
The Insuring Agreement
This is a summary of the major promises of the insurance company and states what is covered. In the Insuring Agreement, the insurer agrees to do certain things such as paying losses for covered perils, providing certain services, or agreeing to defend the insured in a liability.
The Exclusions
Exclusions take coverage away from the Insuring Agreement.
The Conditions
Conditions are provisions inserted in the policy that qualify or place limitations on the insurer’s promise to pay or perform. If the policy conditions are not met, the insurer can deny the claim.

Let us try to understand the basic Newborn Policies

(now this may vary in different companies and policies)

• Newborns begin acquiring health care expenses at birth.
• During the first 30 days , a baby is covered under their mother’s policy and deductible . However, the extension of coverage ends on the 31st day. Fortunately, childbirth triggers a health care special enrollment period. If you want newborn baby health insurance, you need to update your plan within 60 days after childbirth.

Obtaining Newborn Health Insurance Coverage

There are a few ways babies can be covered. If the mom has an insurance plan, the newborn is covered upon delivery and up to 30 days after. In some cases, plans allow this coverage to extend up to 60 days. If the parents are married and are both insured, the newborn will have dual insurance.

If One Parent Has Health Insurance Coverage
If the parents are unmarried , the baby is typically included in their mom’s insurance plan for the first 30 days. The newborn can go on the dad’s policy if paternity has been established. That said, this depends on the type of health insurance plan the father has

For married couples , the baby can have dual insurance if both are insured. Otherwise, the baby can go to the parent who has coverage.
If Both Parents Have Health Insurance Coverage
If both parents have health insurance policies, the baby may be eligible for dual insurance. But that still depends on the situation.
Either insurance policy could cover the baby if the parents are unmarried. However, covering them on the father’s insurance may be harder.

The baby could have primary and secondary insurance coverage if the parents are married . If the child’s parents are divorced, the party responsible for the baby’s health insurance is pre-determined by the court through a Qualified Medical Child Support Order (QMCSO).

The Best Ways to Get Health Insurance for Babies

• There are various ways to get health insurance for babies. -Parents can add them as dependents to their existing health care plans.
• You may also find a separate policy for your baby: It’s possible to get insurance exclusively for a baby. There are two ways to do this. You can buy an individual plan through the marketplace or directly from an insurance provider. Another option is for you to enroll your child in CHIP . If you plan to do the latter, make sure you check the eligibility requirements in your state.

Now after getting the basic understanding of new borns and policies let's look at this case: Bombay HC says new born means full-term and pre-term baby; directs insurance firm to pay medical expenses to mother of twins

In September 2018, the woman delivered twin baby boys at 30 weeks' gestation in an emergency Caesarean surgery. The babies were premature and had to be admitted to the NeoNatal Intensive Care Unit for life-saving treatment.
After their discharge, the petitioner submitted a claim to the insurance company and claimed Rs 11 lakh for the expenses incurred by her.
The insurance company opposed the petition and said the petitioner's twins developed complications due to their premature birth and would not have occurred in a baby born full-term.

However, the bench refused to accept this argument and said the insurance company's rejection of the petitioner's claim was "contrary to law, unreasonable and arbitrary, and liable to be set aside".
Hence, not only the claims were cleared but they also had to pay an additional sum of Rs five lakh for attempting to interpret clauses in its insurance policies, contrary to their true spirit, only with a view to avoid honoring claims