Placenta Praevia Dr Youssif

Placenta Praevia Low Placenta

General

Placenta links the baby with the mother's blood system and provides the baby with its source of oxygen and nourishment. The placenta is delivered after the baby, and is also called the afterbirth.

Placenta Praevia is a complication of pregnancy. The placenta develops in the lower segment of the uterus and may reach or covers part of or all cervix i.e. neck of the womb. Four to five every 1000 pregnant women have low placenta.

Bleeding may occur in the second half of pregnancy. The lower part of the uterus stretches and the placenta may separate from the uterus, causing vaginal bleeding which may be severe and this may threaten the health and life of the mother and baby.

Grades

Grade I      The placenta is low in the uterus but does not reach the cervix. .

Grade II     The lower edge of the placenta reaches the opening of the cervix, but does not cover it.

Grade III   The placenta partially covers the cervix.

Grade IV    The placenta completely   covers the cervix

The first two are more common and the baby may be delivered vaginally.

In the third and fourth Grades birth of the baby will be by Caesarean section.

Diagnosis

An Ultrasound scan in early pregnancy may show the placenta to be close, or even covering the cervix. It is reassuring to know that most will not be low placenta as the baby grows and uterus enlarges the placenta will be pulled away from cervix. A low-lying placenta at 20-week scan, may not present a problem near full-term. An extra ultrasound at 36 weeks, in the majority of cases, will show that the placenta is no longer low

If the placenta stays low in the womb, the baby may still be lying breech i.e. bottom first or transverse i.e. lying across the womb around the time of birth.

Women with placenta praevia usually need a caesarean section and may need a blood transfusion.

Rarely, the bleeding is so severe that the only way it can be controlled is by removing the womb (a hysterectomy).

If there is a lot of bleeding before the baby is due to be born, you may have your baby by caesarean section. The earlier the baby is born before the due date, the higher the risk of health problems. The risk is greatest if the baby is born very early, that is, before 31 completed weeks of pregnancy. Premature babies may have problems with feeding and breathing, and they are at greater risk of infection and jaundice. Because of this, early delivery by caesarean section is only considered if the bleeding is severe enough to cause risk to the mother or baby.

Rarely, placenta praevia may be complicated by a problem known as placenta accreta. This is when the placenta is attached to the womb abnormally, making separation at the time of birth difficult. Placenta accreta is more commonly found in women with placenta praevia who have previously had a caesarean section.

Risk factors of having Placenta Praevia

·        Most have no obvious risk factor

·        Second or third baby

·        Previous Placenta Praevia

·        Previous Caesarean section

· A low-lying placenta is often suspected during a 20-week ultrasound scan.

· One in ten of these women will go on to have placenta praevia

· Occasionally placenta praevia may be picked up later in pregnancy

     1. If the baby is found to be lying as breech or transverse lie

     2. If you have been bleeding.

· In most case placenta praevia is diagnosed in the second half of pregnancy

· Transvaginal ultrasound is best to confirm placenta praevia

· If you have placenta praevia you may be offered additional ultrasound scans to investigate and monitor the pregnancy.

Management of the Pregnancy

· Aditional ultrasound is needed to monitor the position of the placenta. If your placenta is no longer low-lying, you will have normal antenatal care.

· If your placenta remains low-lying in the second half of pregnancy (after 20 weeks), you will have at least one more transvaginal ultrasound scan to check whether the position of the placenta has altered with the development and stretching of the womb.

· Additional extra care will be given based on your individual circumstances.

· If you have major placenta praevia (the placenta covers the entrance to the womb (cervix) or placenta accreta is suspected, you may be offered admission to hospital after 34 weeks of pregnancy. Even if you have had no symptoms before, there is a small risk that you could bleed suddenly and severely, which may mean that you need an urgent caesarean section.

· If you have placenta praevia and have no bleeding, then you may be able to have care at home. However, you should be able to get to hospital quickly and easily at any time. You should call for an ambulance, should this need arise.

· After you have been told that you have placenta praevia, you and your partner should have the opportunity to discuss the options for delivery with your doctor. Depending on your circumstances, you may be advised to have a planned caesarean section.

· You will also need to consider what would happen in the case of an emergency. Your obstetrician should discuss this further.

· In a few instances, a blood transfusion is essential to save the life of the mother and baby. If you feel that you could never accept a blood transfusion, then you should explain this to your obstetrician and midwife as early as possible. You can then discuss any objections or particular questions that you may have.

The Birth of My Baby

· Your Obstetrician will recommend the best way for you to give birth based on your individual circumstances.

· If, your scan at 32 to 36 weeks, your placenta is less than 2 cm from the entrance to the womb (cervix), you will almost certainly need a caesarean section. If this is the case, you should be delivered by the most experienced obstetrician and anaesthetist. This is particularly important if you have previously had a caesarean section.

· Your anaesthetist will discuss the options for anaesthesia if you need a caesarean section. You may need to have a general anaesthetic.

· If you have a caesarean section because of placenta praevia, you are more likely to need a blood transfusion. Blood supplies should be available, as necessary, for your individual circumstances.

· Removal of the womb (a hysterectomy) is sometimes necessary if there is life-threatening bleeding.

· It may be hard to be sure whether there is placenta accreta before surgery, but if this is thought to be likely your doctor may explain it to you beforehand. The risks are particularly high if you have placenta praevia and have had a caesarean section before.

· Some women with placenta praevia and/or placenta accreta may lose such a lot of blood that it endangers their lives. When this happens, there are special hospital procedures to care for women with this condition.

What might happen if I don't have treatment?

You may lose a lot of blood. Placenta praevia is a serious and life-threatening condition. There is a risk of death for you and/or your baby.

Is there anything else I should know?

Avoid sexual intercourse during pregnancy, particularly if you have been bleeding.

You may have a speculum vaginal examination to see where your bleeding is coming from. This is an entirely safe examination.

You should eat a healthy diet rich in iron to reduce the risk of anaemia.

Delivery by caesarean section should be performed after 38 weeks unless there is severe bleeding or another indication.

You have the right to be fully informed about your health care and to share in making decisions about it. Your healthcare team should respect and take account of your wishes.