After about 32 weeks (or a little earlier or later) the baby is growing bigger and the woman may start to feel tired, heavy and large. There are often other discomforts such as heartburn, sore hips or back pain, frequent toilet trips, cramps, restless legs or strong Braxton Hicks contractions. All these can contribute to reducing the woman's interest in sex. The partner may also be less inclined to have sex as the woman's belly enlarges.

Exceptions to this may be if you are recommended to engage in sexual "induction duties" (sex is sometimes used to help ripen the cervix, and hopefully start labour) if the pregnancy goes overdue. This is purely optional but may be a motivation to indulge!

Many couples worry about orgasm or sex starting labour. This will not happen unless the uterus is already on the brink of going into labour. Sex or orgasm may just nudge it past the starting line, but it won't induce labour before it is ready. During the last few weeks of pregnancy, prostaglandins in the man's semen can ripen and soften the woman's cervix, to help it to dilate in labour and reduce the chances of her going overdue.

During the second half of pregnancy the uterus is quite active with Braxton Hicks contractions. These are the practice contractions, or 'dress rehearsals' for labour. When a pregnant woman has an orgasm during late pregnancy, it is normal for her to experience Braxton Hicks contractions for a few minutes to half an hour afterwards.

You can read more about positions for sex as the pregnancy progresses in positions for intercourse.