Effect of analgesics or pain killers in pregnancy

Analgesics are available over the counter in many countries and in pregnancy the common complaints are pain in legs and feet, backache and tiredness and this lead to a tendency to take frequent analgesics in many pregnant women. The common analgesics used are aspirin, codiene, paracetamol and different combination of these.

A pregnant woman should not always take these analgesics regularly, its use should be limited and it is better to rest or use local heat to control the pain and other symptoms.

Though aspirin is not supposed to have any teratogenic effect, even if taken in first trimester of pregnancy, however it has many other effects on pregnancy and the newborn. Similarly other analgesics too have some effects on pregnancy and new born which is described below :-

Effect of aspirin in pregnancy

Aspirin acts by inhibiting prostaglandin synthesis. Prostaglandin is a smooth muscle stimulating lipid, found in practically all tissues in the body, but more so in the reproductive system. This substance is released from the tissues by nervous, humoral, chemical and physical stimulation and this has widespread actions in the body. When aspirin inhibits prostaglandin synthesis , uterine contractility is decreased. Hence there is delayed onset of labor in habitual aspirin users. The duration of labor is also often longer and the pregnancy often becomes postdate.

In fetus aspirin can cause premature closure of a part of the circulatory system, called the ductus arteriosus, thereby interfering with oxygenation of the fetus.

Aspirin also causes increased bleeding tendencies, it prolongs the bleeding time, that is it takes longer for a clot to form. It does not let the platelet faction of the blood to aggregate. When bleeding occurs, platelets aagregate at the site immediately, to start forming a clot. This property of the aspirin to inhibit aggregation of platelets can be beneficial or detrimental. Low dose of aspirin can be beneficial in preventing toxaemia of pregnancy and fetal wastage from autoimmune disorder. It is harmful because it increases the risk of bleeding in pregnancy, as well as at delivery.

Effect of codiene in pregnancy

Codiene is a pain reliever, it also has a sedative effect and is alsoaddictive. It is best avoided in pregnancy as it can cause withdrawl symptoms in mother as well as the new born as it can cross placenta. It also causes constipation which is harmful in pregnancy.

Effect of paracetamol in pregnancy

Paracetamol is also called acetaminophen. Paracetamol inhibits synthesis of prostaglandins and causes a little platelet aggregation. However this drug is not habit forming and once stopped, the effects are reversible, hence its use is preferred to that of the aspirin. The use of very large doses of paracetamol can cause liver damage in the mother and renal change in the fetus. However if taken in minimal doses it is the most preferred analgesic in pregnancy and much more safer than aspirin or codiene.

Effect of anti inflammatory drugs in pregnancy

These drugs are used to relieve pain due to inflammatory changes in tissues. Inflammation is a reaction by the tissue to any infection, injury, toxin or degenerative processes. The main use of these drugs are to relieve joint pains due to arthritis or chronic back pain due to pelvic inflammatory disease.

Anti inflammatory drugs too have similar side effects like analgesics. Some anti inflammatory drugs used commonly are indomethacin, brufen, diclofenac etc.

Thus the conclusion is that in pregnancy it is better to avoid analgesics or pain killers and alternate methods like hot fomentation, rest etc should be used to get relief from pain and tiredness, however if it is at all necessary to take drugs, paracetamol in minimal quantity for minimal period should be taken.