This is a topic a lot of couples are reluctant and/or embarrassed to discuss with their doctor. It is however a very important issue. Couples should discuss it between themselves and be open and truthful about your feelings. There may be women who may lose their sexual urges as their body changes. There are women who feel fat and undesireable as their abdomen grows. There is also the problem of finding the right position that would be comfortable for the couple. The couple should also discuss it with their doctor to find out if the woman is having a normal pregnancy or is she at high risk for complications.
If the couple decides that both are still open to intimacy, there are couple of warnings. If they choose to have oral sex, the man should refrain from blowing into the vagina as it may cause air embolism. That is the blockage of the blood vessel by an air bubble. It may be fatal to both mother and baby. Another warning is that if the man suspects that he may have an infection (STD), he should refrain from intimacy.
Most common question is, "Will it be safe for the baby?" Most definetly yes. Your baby is protected by the amniotic sac which is a thick bag holding the baby and the fluids. The other common question is, "Can we have sex until the baby is due?" Yes if there are no contraindications or if your care provider has not asked you to refrain from having sex. Having an orgasm can stimulate contractions. Also, the semen contains prostaglandins that can prepare you for labor plus antibodies that can be good for you. The third most common question is, " What position is best?" You and your partner may want to experiment on what is the most comfortable for you both. Laying on your side (spooning position) may be the best. But feel free to be creative.
Of course if you experience pain, spottting/bleeding, discharge or prlonged orgasm, you need to call your doctor immediately.
For those who choose to abstain from sex during pregnancy, I would recommend spooning, kissing and caressing. I guarantee that these activities is equally enjoyable.