The causes of vaginal discharge in pregnancy are the same as in non-pregnant women: hormones, infection, non-infective irritation and cervical ectropion (previously known as cervical erosion).
When discussing vaginal discharge with your midwife, there are certain bits of information she'll want to know: colour of discharge, consistency (watery or mucousy or lumpy, like cottage cheese), whether it smells unusual, whether it is bloodstained, and whether it causes irritation or soreness.
Pregnancy hormones can cause an increase in vaginal discharge, but this should be clear, mucousy, non-irritant and non-smelly.
Any discharge that is discoloured, irritant, bloodstained or smelly should be checked for infection. The two most common vaginal infections are thrush and bacterial vaginosis (BV). Thrush tends to produce a white, lumpy, irritant discharge, and BV tends to produce a more watery, non-irritant, smelly discharge. Sometimes the infections occur together, so a swab is important in order to make an accurate diagnosis. It is important to treat both infections in pregnancy, especially BV, which is associated with a threefold increase in the risk of premature labour.
Non-infective irritations are usually caused by toiletries or vaginal deodorants.
Cervical ectropion is mentioned again below as it can also cause vaginal bleeding, as well as a mucousy discharge.
Vaginal bleeding can occur in pregnancy for all kinds of reasons. Some women continue to get cyclical, period-like bleeding in early pregnancy, and a few will appear to have 'periods' throughout the pregnancy.
Cervical ectropion is common in pregnancy, as it is a hormone-sensitive condition. In normal circumstances, the outer surface of the cervix is covered by a tough membrane. In cervical ectropion, the soft membrane that normally lines the canal of the cervix spreads onto the outer surface also. The soft membrane contains a lot of mucus-producing glands, so a mucousy vaginal discharge is a common symptom. The membrane is also rather delicate and prone to bleeding, so bloodstained discharge or frank bleeding can also occur. The bleeding is only light, and is painless.
Bleeding in early pregnancy
Bleeding in the first 13 weeks of pregnancy (first trimester) may be due to a threatened miscarriage or an ectopic pregnancy, so must always be reported to the midwife.
The amount of bleeding with threatened miscarriage is variable. It may start as just a bit of spotting or be like a light period. It may be painless, or be associated with a period-like pain in the lower abdomen. If the midwife suspects a threatened miscarriage, she can arrange a scan to see if the foetal heartbeat can be seen.
If everything is OK, she will advise bed rest until the bleeding has stopped.
Ectopic pregnancy describes a pregnancy outside the uterus (womb), most commonly occurring in a fallopian tube. As the foetus grows, the tube becomes distended and painful, and will eventually rupture if the condition isn't diagnosed. The abdominal pain usually starts in the second month of the pregnancy, and is often accompanied by vaginal bleeding. The diagnosis is confirmed by a scan. A ruptured ectopic pregnancy must be treated immediately, as it can cause fatal haemorrhaging.
Vaginal bleeding after 28 weeks
Bleeding after 28 weeks is referred to as ante-partum haemorrhage (APH). Bleeding may be light or heavy, painless or painful. Full investigation of APH is very important, as it can be due to one of two serious obstetric conditions, placenta praevia, or placental abruption. Both of these conditions can be life-threatening for mother and baby, so immediate contact with the midwife is important for any pregnant women who bleeds after 28 weeks, even if the bleeding is not heavy. (Both conditions have been described in detail in previous features.)
So the message is: always report any discharge or bleeding in pregnancy to the midwife. It may not represent a serious problem, but needs to be fully assessed.