MANY old wives’ tales evolve around women’s traditional concerns such as pregnancy and sex.
In modern science, it would have undergone the scrutiny of research and investigations.
However, even in the presence of robust evidence, one may not overcome the fear and guilt of causing harm during pregnancy.
This week, we address the belief of sex causing harm or even miscarriage during pregnancy.
It would be interesting to see whether the power of science or old wives’ tale will prevail.
Dear Dr G,
My name is Joe. I am 28 years old.
I am delighted that my wife is pregnant again after her last miscarriage.
Six months ago, my wife experienced bleeding after we had sexual intercourse, two and a half month into her pregnancy.
We both feel very sad and guilty as many of our friends told us it was due to our sexual intercourse, which was“disturbing” the baby.
We are a lot more cautious this time and the pregnancy is going well into the fifth month now.
The problem is, my wife and I both have very high libido, and this abstinence is affecting our relationship.
We have not have sex for at least four months and we have to wait until the baby is born.
I read on the Internet that sexual activity will not harm the baby during pregnancy.
But my parents think this is a western view and should be ignored.
Can you tell me what are the causes of a miscarriage?
Do you think we should continue to avoid sex until the baby is born?
Miscarriage is a natural death of a fetus before it is able to survive independently.
In medicine, the fetal death before the 20th week gestation is considered miscarriage and stillbirth after that cut-off time.
Miscarriage is the most common complication during early pregnancy.
It is estimated to affect 10% to 20% of women who are aware of the pregnancy, and the prevalence can rise to 30% to 50% of all fertilisations.
It is also estimated that around 5% of women will have two miscarriages in a row.
Eighty percent of all miscarriages occur in the first trimester, with half of them caused by fetal chromosomal abnormalities.
Other common causes of fetal death may be due to ectopic pregnancy or implantation bleeding.
However, the majority of the causes of spontaneous abortion are idiopathic.
These include older parents, previous miscarriage, diabetes, alcohol and exposure to tobacco smoke.
The risk of pregnancy loss for maternal age of less than 35 years old is less than 10%, and the risk escalates 40% by the age of 40.
Maternal medical conditions such as diabetes can increase the risk of fetal loss.
Other medical conditions such as polycystic ovarian syndrome (PCOS) and hypothyroidism are also recognised to be associated with pregnancy loss.
Maternal related causes such, as chlamydia, rubella and mycoplasma that can be transmitted from placenta to fetus may also be responsible.
Two interesting risk factors recently implicated as the 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 increase time spent exercising were associated with higher risks of fetal 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 has a miscarriage rate of 25% compared to 13% in the non-caffeine group.
In a subsequent 2009 study, light or moderate caffeine consumption (up to 300mg) was found to have no effect on pregnancy.
The only partner-related risk factor associated with pregnancy loss is sex during pregnancy.
Sex during the first trimester has often been assumed by doctors to be a cause of miscarriage.
However, the association has never been put through the rigour of scientific scrutiny, and I guess it would be difficult to conduct trials.
Most research suggests that overall sexual desire decreases during pregnancy.
In recent studies, it is noted the decrease may only be obvious in the first trimester, but enhanced after the third month.
Pregnant women reported greater sexual satisfaction throughout the pregnancy. This may be related to the feeling of happiness and attractiveness.
Sexual activities have also been suggested as a way to prepare the maturation of the cervix before delivery, as the natural prostaglandin from the semen make the cervix more flexible for dilation.
Sex during pregnancy is generally perceived to be a low-risk behavior, as the fetus is protected from thrusting penis by the cervix and the amniotic fluid.
However, intercourse is also been implicated in premature labour and ruptured uterus.
Doctors tend to advice pregnant mothers engaging in “cautious” sexual activities during pregnancy throughout the gravidity is safe.
I myself find it difficult to define how “cautious” is “cautious sex” during intercourse.
I often find it difficult to advise couples when it comes to the risk of sex causing a miscarriage, as the fear of causing damage often dampens the pleasure.
I guess I also have the same advice with my colleagues - “cautious” sex may be only way to see desperate Joe through the next four months.