If you're pregnant, you may have questions about sex during pregnancy. Here's what to know.

The amniotic fluid in the uterus and the strong muscles of the uterus protect your growing baby. Having sex won't affect your baby if you don't have health concerns during pregnancy such as preterm labor or placenta problems. But being pregnant can cause changes in your level of comfort during sex and in your interest in sex.

Miscarriage is the sudden loss of a pregnancy before the 20th week. Having sex while pregnant won't cause a miscarriage. Most miscarriages happen because the fetus isn't growing as it should.

It's common to have cramps or spotting after sex or orgasm. But if you have bad cramping that doesn't go away or heavy bleeding that is like a menstrual period, contact your healthcare professional.

Most sexual positions are OK during pregnancy if they are comfortable for you. If a position bothers you, try another. As your belly grows, see what works best. Keep pleasure and comfort in mind.

Having a sexually transmitted infection while pregnant can cause serious health problems for you and your baby. Avoid vaginal, oral and anal sex if your partner has a sexually transmitted infection.

Use a condom if:

• You or your partner has sex with other people.
• You have sex with a new partner while pregnant.

Having sex or having an orgasm can cause the uterus to contract. This most often isn't a reason to worry.

But your healthcare professional might suggest not having sex if:

• You have vaginal bleeding.
• You leak amniotic fluid.
• Your cervix begins to open early, called cervical incompetence.
• Your placenta covers your cervical opening partly or all the way, called placenta previa.
• You have a history of starting labor early or giving birth early.

That's OK. You may have nausea or be too tired for sex. Or you or your partner might not want to have sex. Share your needs and worries with your partner in an open and loving way. If you don't want to have sex, there are other ways to be close. Try cuddling, kissing or massage.

The amniotic fluid in the uterus and the strong muscles of the uterus protect your growing baby. Having sex won't affect your baby if you don't have health concerns during pregnancy such as preterm labor or placenta problems. But being pregnant can cause changes in your level of comfort during sex and in your interest in sex.

Most sexual positions are OK during pregnancy if they are comfortable for you. If a position bothers you, try another. As your belly grows, see what works best. Keep pleasure and comfort in mind.

Having a sexually transmitted infection during pregnancy can cause serious health problems for you and your baby. Avoid all forms of sex — vaginal, oral and anal — if your partner has an active or recently diagnosed sexually transmitted infection.

Use a condom if:

• You're not in a mutually monogamous relationship
• You choose to have sex with a new partner during pregnancy

Breast stimulation, female orgasms and certain hormones in semen called prostaglandins can cause uterine contractions.

Your health care provider might recommend avoiding sex if:

• You have unexplained vaginal bleeding
• You're leaking amniotic fluid
• Your cervix begins to open prematurely (cervical incompetence)
• Your placenta partly or completely covers your cervical opening (placenta previa)
• You have a history of preterm labor or premature birth