Battle of the bulges

Dear Dr. G,

I am 30 years old with a pregnant wife and am looking forward to life as a parent.

This is especially welcome as my wife miscarried a year ago.

Two months into her previous pregnancy, my wife experienced bleeding after we had sexual intercourse. When she miscarried, we felt sad and guilty as many of our friends told us it was because of sexual intercourse.

On the other hand, our obstetrician assured us intercourse does not harm the foetus if we are cautious.

We are much more cautious this time and her pregnancy is into the fifth month and progressing well.

We haven’t had sex since she learnt she was pregnant again, but my wife seems to have a heightened sex drive and avoiding sex is really putting a strain on our relationship.

What is Dr G’s opinion on sex during pregnancy? Does it affect a woman’s libido? Can sex during pregnancy result in miscarriage and causes them, for that matter?

Should continue to avoid sex until the baby is born?

Yours truly,
Cautious Charlie

Pregnancy triggers many changes in a woman – including her sex drive. High levels of estrogen and progesterone, as well as increased blood flow to the genitals may lead to heightened sexual desire. During the first trimester, it is common to observe uncomfortable physical symptoms including nausea and vomiting that tends to lower libido.

Sex drive heightens during the second trimester, as surging hormones enhances arousal, sensitivity, and pleasure. Pregnant mothers often face the challenges in the third trimester as weight gain, exhaustion and bodily changes make sexual activity difficult. Pregnant women report greater sexual satisfaction, which may be related to the feeling of happiness and attractiveness.

It has also been suggested that sexual activities prepare the maturation of the cervix before delivery, as the natural prostaglandin from semen make the cervix more flexible for dilation.

Sex during all stages of pregnancy is perceived to be low-risk behaviour, as the foetus is well protected from a thrusting penis by the cervix and the amniotic fluid. Despite any concerns about overly-vigorous thrusting, the risk of harm to the foetus is minimal during most stages of pregnancy.

However, intercourse is implicated in premature labour and ruptured uterus in some high-risk pregnancies. These may include placenta previa, twin pregnancy and preeclampsia.

For other non-high-risk pregnancies, doctors tend to advise pregnant mothers to engage in “cautious” sexual activity but I find it difficult to define what a “cautious” level means.

A miscarriage is the natural death of a foetus before it can survive independently. Foetal death before the 20th week of gestation is considered a miscarriage and after that cut-off period, this is defined as a stillbirth. Miscarriage is the most common complication during early pregnancy and estimated to affect 10% to 20% of women who are aware of the pregnancy – perhaps rising up to 50% of all fertilisations. It is also estimated around 5% of women will have two miscarriages in a row. Eighty% of all miscarriages occur in the first trimester, with half caused by foetal chromosomal abnormalities. The causes of most spontaneous abortions are unknown.

Risk factors for miscarrying are well-documented. These include older age of parents, previous miscarriage, diabetes, alcohol and exposure to tobacco. Two risk factors recently implicated as causes of spontaneous abortions were exercise and caffeine.

A study of more than 92,000 pregnant women discovered the risk of miscarriage is higher prior to 18 weeks’ gestation. High-impact exercise and increased time spent exercising were associated with higher risk of foetal loss. In a separate study, caffeine consumption was correlated with miscarriages. In a study of more than 1,000 pregnant women, the consumption of more than 200mg of caffeine showed a miscarriage rate of 25% compared to 13% in the non-caffeine group. In a subsequent 2009 study, however, low or moderate caffeine consumption (up to 300mg) was found to have no effect on pregnancy. Hence, sex is not the only culprit that is implicated for miscarriages.

Even in the presence of robust evidence, there is fear that sex will cause harm to the next generation. This has never been put through rigorous scientific scrutiny, and it would be difficult to conduct trials. When Dr G is put on the spot he finds it difficult to advise couples, as the fear of causing damage often dampens the pleasure. I can only give the same advice to Cautious Charlie to have “cautious” sex which could see him through the next few months.