If you're a gay man or a lesbian, it doesn't mean you have to go through life without having a family of your own. The options available to potential gay and lesbian parents are wider now than ever before.
Dr Justin Varney, a public health consultant in London, says: "Gay men and lesbians are in the wonderful position where getting pregnant is a choice. It's a serious choice, but it is a choice."
But it's important to think through the implications of starting a family, says Dr Varney. "There are good organisations to talk to, or other gay parents who can tell you what having a child is like."
Some lesbian, gay or bisexual parents had children when they were in straight relationships that have ended. Otherwise, there are four main ways to have a child:
This is where a man donates sperm so a woman can inseminate herself. She can be single or in a relationship.
Donor insemination can be performed at home using sperm from a friend or an anonymous donor, or at a fertility clinic using an anonymous donor.
If you decide to look for donor insemination, it's generally better to go to a licensed clinic where the sperm is screened to ensure it's free from sexually transmitted infections and certain genetic disorders. Fertility clinics also have support and legal advice on hand.
Thanks to recent changes in the law, lesbian couples who are civil partners at the time of conception and conceive a child through donor insemination – either at a licensed clinic or by private arrangement at home – will now both automatically be treated as their child's legal parents.
So too will couples who aren't civil partners at the time of conception but who conceive through donor insemination at a licensed clinic.
However, when non-civil partners conceive through donor insemination by private arrangement at home, the non-birth mother has no legal parenthood and will have to adopt the child to obtain parental rights.
Read more about artificial insemination.
This is typically when a lesbian and a gay man team up to have children together, although one or the other may also be straight or bisexual. The man donates the sperm and both parties share responsibility for and custody of their child.
As a co-parent, you won't have sole custody of the child. It's vital to get legal advice beforehand. There are many details to be worked out, such as what role each parent will take, how financial costs will be split, and the degree of involvement each will have with the child.
Adoption for same-sex couples
It's now possible for same-sex couples in the UK to adopt a child together.
Couples can apply to adopt through a local authority or an adoption agency. You don't have to live in the local authority you apply to.
Find out more about adopting or fostering a child from the care system in England and Wales.
Surrogacy is where another woman has a baby for a couple who can't have a child themselves. It's an option if you're a gay man, where the surrogate mother's egg can be fertilised by either you or your partner's sperm.
In reality, surrogacy is rare because it's difficult to arrange. Although it's legal in the UK, no money other than "reasonable expenses" can be paid to the surrogate, and there's nothing to stop her keeping the baby after it's born. It's also illegal to advertise for surrogates.
For more information on the legal position in the UK, visit the COTS website.
Now, read how to protect your fertility.