Family - Problems during Pregnancy

However, there are problems in about 3-4% of all pregnancies, and while many of these may actually be quite minor and easily sorted, some are not

In both cases knowing about them in advance can help parents and doctors plan for the mother and baby's safety during pregnancy and, if necessary, assess any special requirements or care.

Ectopic Pregnancy
Fallopian tube (Ectopic) pregnancies, which is where the blastocyst implants in the tube lining, occur in about 15% of conceptions. They are usually the result of the sphincter muscle not opening fully or damage to the Fallopian tube. Most are reabsorbed, but a few implant and develop, which can cause the Fallopian tube to rupture and split, and while that might sound serious, nowadays most cases can be treated.

Placenta Praevia
If the placenta implants low down in the uterus and blocks the cervix, known as placenta praevia, it can have fatal consequences if not diagnosed before birth because the baby literally won’t be able to be born and will dislodge the placenta in the attempt, thus interrupting the blood supply to the baby, and causing the mother a potentially serious haemorrhage. However in the UK ultrasound scanning will check the position of the placenta through the pregnancy, so a Caesarean section can be performed if it still lies across the cervix as the due date approaches. Usually, however, intervention is not required because as the uterus expands, most placenta praevias will rise with it, away from the cervix.

Cervical Incompetence
In a very few pregnancies, the tightly closed cervix may begin to open before term. This allows the amniotic sac to bulge through into the vagina and usually results in miscarriage. To prevent this a cervical suture can be inserted, and this will be  removed a few days before the due date.

Pre Eclampsia
The syndrome that occurs before the potentially fatal eclampsia, pre-eclampsia is experienced by about 10% of pregnant women. Symptoms occur after 20 weeks of pregnancy, and early indications include high blood pressure, oedema, and protein being present in the urine (known as proteinuria), despite the mother feeling quite well in most cases. Later on symptoms may develop into nausea, dizziness, and vomiting, and then into the full fits that characterise eclampsia.

Nobody quite understands why it happens, but recent research, as reported in New Scientist, seems to suggest that it may be a result of the placenta not implanting as deeply as it should. Why this might happen and what can be done about it is the subject of further research. It is more common in multiple births, first births and mothers over the age of 35. Also where the womn has been with the baby’s father for a short time.

Mothers with mild pre eclampsia are monitored closely, and if it develops they will be admitted to hospital and early delivery of the baby by Caesarean section may be required, although most are labour induced – generally only a Caesarean Section if the pre-eclampsia is very severe, and there is a very premature, very small baby, or if the mother has had a previous Caesarean Section. For further information visit www.pre-eclampsia.co.uk

Gestational Diabetes
During pregnancy a small number of women do not produce sufficient insulin to keep blood levels normal. Women at risk include those who have a family history of diabetes, which is generally picked up at your booking in appointment. Gestational diabetes is usually detected in the second half of pregnancy when the baby is found to be much bigger than expected or glucose appears in the mother’s urine. Gestational diabetes disappears once the baby is born, but does increase the risk of the woman developing type 2 diabetes later. This risk is reduced if she breastfeeds her baby. For further information visit www.diabetes.co.uk

Miscarriage
There is no one reason for why a miscarriage occurs, but they affect about 30% of all pregnancies, with 25% happening before the pregnancy is even diagnosed. That leaves 5% of diagnosed pregnancies that may result in a miscarriage, and of  these, the risks are higher earlier on than they are after 12 weeks, and mothers who are older or carrying more than one baby tend to have a higher risk. It can be difficult to know for sure why a miscarriage occurs, but uterine abnormalities, hormonal imbalances, bacterial and viral infections, immune problems (such as rhesus incompatability) and cervical  incompetence are amongst the most common.

Miscarriage can be a lonely and distressing experience for the mother and the rest of the family. For further information and support visit www.miscarriageassociation.org.uk

Genetic Abnormalities

Testing for Problems
Various tests may be offered to check the health of the baby. Screening tests assess the risk of the baby being born with certain conditions, such as spina bifida or Down's syndrome, but cannot give a definite "yes" or "no" diagnosis. The overall calculation of risk may include more than one type of screening test plus the woman's age. Other tests can confirm whether the baby has a certain condition, but for many women, the decision to have these tests is a difficult one: it's important to consider what it would mean if the results were abnormal. If the woman screens positive further tests are offered, some of which are diagnostic.

Blood tests
Blood tests are offered from 11-20 weeks. The levels of a number of chemicals can be measured in the mother's blood to help estimate the risk of the baby suffering from certain testable conditions, such as spina bifida or Down's syndrome.

Different tests measure different hormones or proteins, or combinations of these, including alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), oestriol and inhibin A. If hCG and AFP are used as a screening test, this is often called the 'double test'. If oestriol is added to the double test, this is known as the 'triple test'. If inhibin A is added to the triple test, it becomes the 'quadruple test'.

Ultrasound scanning
In early pregnancy, ultrasound is used to check the size of the fetus, whether there is more than one baby, and the position of the placenta.

At 18-20 weeks of pregnancy, most women have a more detailed ultrasound scan. The ultrasonographer makes sure the right amount of fluid surrounds the baby, examines the baby's head, heart, spine, limbs and internal organs in detail and checks the position of the placenta (which joins the mother and fetus and allows exchange of nutrients and waste products between them). This scan can identify some physical abnormalities, such as cleft lip or skeletal abnormalities, and can confirm spina bifida if blood tests have shown the baby is at high risk. It cannot diagnose Down's syndrome.

Nuchal translucency scan
This is a screening test for Down's syndrome that's usually offered at 11-14 weeks. It involves an ultrasound scan to measure the thickness of the layer of fluid at the back of the baby's neck. Babies with Down's syndrome have a thicker layer. If it is thicker than average, women are usually offered an amniocentesis for diagnosis.

Amniocentesis
Amniocentesis is a diagnostic test that some women choose to have, usually between 15 and 19 weeks of pregnancy. This is an accurate way of finding out whether the baby has a number of genetic or inherited disorders, such as Down's syndrome or cystic fibrosis. Amniocentesis carries a 0.5 -1% risk of harming the baby or causing a miscarriage. It is usually only offered to women when screening tests show they may be at a higher risk of having a baby with a genetic disorder, or to women over 35 years old.

A fine needle is inserted into the amniotic fluid surrounding the baby. Ultrasound is used to guide the positioning of the needle. The amniotic fluid contains some cells from the baby that are cultured in the laboratory and then analysed in detail. Full results can take up to four weeks

Chorionic villus sampling (CVS)
For CVS, a fine instrument is inserted through the woman's cervix into the uterus and a sample of the chorionic villi (tiny fingerlike projections found in the placenta) is removed. These have the same genetic material as the baby.

This test looks for similar problems as amniocentesis, although it does not test for neural tube defects. CVS is performed earlier - usually between 10 and 12 weeks of pregnancy, and the results are usually available within a few days. The results are not quite as accurate as amniocentesis, the procedure is technically quite difficult and it is not always successful. There is a slightly higher risk of miscarriage with CVS - approximately 1-2%.

Further information

National Institute for Clinical Excellence (NICE)
Routine antenatal care for healthy pregnant women.
www.nice.org.uk

Informed Choice - MIDIRS
www.infochoice.org