No one marries with the intention of getting divorced, but about half of all marriages in the U.S. will end in divorce. Divorce and second marriages can complicate the process of estate planning and present a number of challenges.

There are many things blended families need to consider when updating their estate plans.

Review Your Plan

Estate plans should be reviewed and updated with each major life event, including divorce, marriage and the birth of children. Failure to update your wills, trusts and other accounts can have disastrous consequences after your death. Rather than your assets being left to your current spouse, they may be given to your ex-spouse.

Documents, insurance policies and accounts should all be updated to reflect your new marital status.

If you have children from previous marriages, it's important to take steps to ensure that they inherit the assets you desire after your death.

"When new spouses are named as sole beneficiaries on retirement accounts, life insurance policies, and other accounts, these spouses will not be legally required to share any assets with the children," says the Law Offices of Marc J. Blumenthal, Ltd.

Taking the time to review and update your estate plan will save you and your family from grief in the future. Your estate planning attorney can help with this process.

A Simple Will May Not Be Enough

A simple will may not cut it if you want to protect your biological children's ability to inherit. If you draft a will that leaves everything to your new spouse, be aware that he or she can cut out the children from your previous marriage entirely. There is no obligation for him or her to give these children anything.

Drafting Trusts Can Preserve Your Wishes

Trusts are a practical way to ensure that your wishes are met after your death. You have quite a few options here.

You can create a trust that will leave assets to your new spouse during his or her lifetime, and then pass all of those assets to your children upon his or her death. This is known as an AB trust.

There's also an ABC trust. In this case, various assets are allocated to each trust, which has its own set of rules.

These types of trusts were once used to avoid estate tax, but now that divorce and second (or third) marriages are more common, they're frequently used for blended families. Although a bit complex, these trusts ensure that your wishes are met and that everyone in the family inherits as you intended.

A trust can also protect your assets in the event that your spouse remarries after your death.

Choose Your Trustee Wisely

One major - and overlooked - challenge of estate planning is choosing a trustee. There is a very real possibility that there will be tension between your spouse and your children. The trustee may have to act as referee between these parties, so choose someone who will carry out your wishes as intended.

Leaving Assets to Biological Children Upon Death

One way to quell family quarrels is to simply leave some assets to your biological children upon your death. When doing this, your children won't have to wait for your spouse to die in order to inherit.