New screening -Group B Streptococcus -(GBS). GBS is carried in the genital tract and gut of many healthy people -occur after premature or prolonged rupture of the membranes. -babies are affected by GBS disease, a disease, that can cause severe problemsincluding meningitis and death. -screening is offered by vaginal swabs at 35–37 weeks.

Mid-stream urine testing -Screening for asymptomatic bacteriuria will lead to pyelonephritis. -Pyelonephritis can be life-threatening - lead to miscarriage and premature labour. Treatment is appropriately antibiotics.

Screening for anaemia -Anaemia is one of the commonest complications of pregnancy. -The most common reason for iron deficiency anaemia in pregnancy is the increased demands of the fetus for iron. -Risk factors for the development of iron deficiency in pregnancy include iron deficiency prior to pregnancy hyperemesis vegetarian or vegan diet multiple pregnancies

pregnancy recurring after a short interval blood loss. -Pregnant women should be offered screening for anaemia in early in pregnancy and at 28 weeks. -This allows enough time for treatment if anaemia is detected. -Haemoglobin levels pregnancy (that is, 11 g/dl at first contact and 10.5 g/dl at 28 weeks)

- treatment with iron can be started and a blood test for serum ferritin sent at the same time to confirm iron stores are low. - The woman should be asked if she is known to have a haemoglobinopathy. -These women should be directly referred to an Obstetric Haematology clinic for assessment.

Screening for red cell antibodies -All pregnant women should be offered antenatal testing to assess ABO and rhesus status and to look for red cell antibodies. -Red cell antibodies are antibodies against red cell antigens, and the relevance to pregnancy will vary depending on the type and level of the circulating antibody. - Some antibodies occur naturally, without any sensitising event, but most of the important ones require a sensitising event such as a previous pregnancy or transfusion

- Antibodies to the ABO system tend to be naturally occurring, as does anti-E. -Once an antibody has been identified it will be relevant to understand the issues for both the mother and baby. -For the mother with any red-cell antibody the major issue is related to increased difficulty in cross matching blood. -Women with antibodies will not be able to undergo rapid electronic cross matching and therefore for women at any increased risk in labour of hemorrhage, crossmatching in the early stages or before planned birth may be prudent.

-For the fetus, red-cell antibodies are of significance as IgG antibodies can cross the placenta. - If the fetal red blood cells carry the antigen the antibody is directed against they will be destroyed. -This can lead to fetal anaemia and in severe cases cause fetal hydrops. - Jaundice and kernicterus (brain damage caused by very high unconjugated bilirubin levels) in the neonatal period are the major neonatal risks.

-Routine antibody testing in pregnancy aims to: identify Rhesus-negative women who will be eligible for anti-D immunoglobulin prophylaxis • identify women who are difficult to cross match so that steps can be taken to minimize risk • identify women with antibodies that put the fetus at risk of haemolytic disease of the newborn (HDN). -all women should be tested at booking and again at 28 weeks' gestation -There are many red cell antibodies and it is useful to understand which ones are important causes of HDN.

Antibodies to the Rhesus antigens are the most common to cause problems. • Rhesus D antibodies are the principle cause of severe HDN. • Rhesus c can cause HDN, especially if antibodies to Rhesus E are also present • Rarely antibodies to Rhesus E, e, C and CW can cause HDN. Antibodies to non-Rhesus antigens can also cause HND. Anti-K (Kell) antibodies are an important cause of severe HDN. -These antibodies not only destroy the fetal red cells, but inhibit production in the bone marrow, exacerbating any developing anaemia.

-Other antibodies known to cause HDN less commonly include anti Fya (Duffy), anti Jka (Kidd) and anti S. Antibodies to the ABO system may be detected on routine testing. - In general these occur in Group O women and are naturally occurring anti-A and anti-B antibodies. -Because these antibodies are IgM antibodies they do not cross the placenta and do not harm the fetus. -Occasionally some group O women produce IgG antibodies when carrying group A or B infants.

-These IgG antibodies can cross the placenta and cause HDN, but this tends to be mild.

How the results are presented Antibody levels are either before there is red cell clumping. Rh-D and Rh-c are always measured and the result will be given in iu/ml hence the higher the result the worse the effects are likely to be. Other antibody levels are expressed as titres. A titre of 1 : 2 means a low level of antibody. that a single dilution there was no clumping of the red cells. A titre of 1 : 16 states that there were four dilutions before the antibody was too weak to clump cells, implying a much higher level of antibody. It is useful to understand that a jump from 1 : 2 to 1 : 4 is a single dilution, as is a jump from 1 : 16 to 1 : 32.

What parents need to know Parents need to understand 1- the purpose of blood group and red cell antibody screening 2- what is being tested for and what the test involves. 3- discussion about the nature and effects of red cell antibodies 4-how and when test results will be available 5- the meaning of the results.

Management when an antibody is detected -discussed with the mother. - the potential for difficulties in crossmatching blood -the potential for fetal or neonatal problems. - If significant antibody titres are found management needs to be discussed, including the need for surveillance for fetal anaemia the possibility of intrauterine transfusion – this would usually be done by the obstetrician managing the pregnancy

Surveillance will depend on 1- the type of antibody found; for some antibodies 2the titre (level) of the antibody the gestation of pregnancy at which it is discovered. -When an antibody is detected that may cause HDN: Referral for discussion with an appropriate consultant/haematology team. Partner testing. This is to determine the potential for fetal risk. Only a fetus that is antigen positive for the antibody found can be at risk. This means if a woman has anti-D antibodies and a Rh-D-positive partner there will be a 50–100% risk of producing a baby who is Rh-D-positive, depending on whether the partner carries one or two Rh-D-positive genes. -the woman understands

the importance of partner testing, the need to be honest if there can be any doubt regarding paternity -Be ware with IVF pregnancies also. Remember to ask whether there has been egg donation Free fetal DNA testing. Where the fetus is potentially at risk because the partner is positive for the antigen to the detected antibody or where partner testing cannot be undertaken typing of the fetal red cell status can be performed on a blood test from the woman. The test is usually carried out between 12–18 weeks. The results are accurate in 99% of cases but in some cases a result cannot be given.

Confirmatory testing. Invasive testing using CVS or amniocentesis is usually undertaken only where there is a need to establish fetal karyotype for other reasons. In cases where ultrasound suggests developing anaemia a fetal blood sample prior to intrauterine transfusion will be tested for fetal blood typing.

On-going surveillance -Once the risk of a pregnancy being affected has been established the timing and frequency of repeat testing of antibody titres can be determined. The need for assessment of the fetus at risk can also be established. Surveillance for fetal anaemia is now undertaken primarily using ultrasound measurement of the blood flow velocity within the fetal brain. -Measurement of the maximum velocity in the fetal middle cerebral artery has been found to be as accurate as the old-fashioned measurement of bilirubin in amniotic fluid, but is without the attendant risks of serial amniocentesis. The frequency of surveillance will be determined by the risk of anaemia, which is dependent on the type and level of antibody and the risk of the fetus being antigen- positive.

Conclusion -Fetal investigations are an integral aspect of antenatal care. Scientists and clinicians have developed a range of new diagnostic and imaging technologies. -The midwife must therefore ensure that women are informed about the benefits and risks associated with these technologies, so that they can make choices to suit their requirements. Undoubtedly, testing technologies profoundly influence women's experiences of pregnancy and their early afachment to their unborn child. Midwives therefore have a duty to prepare women for tests through sensitive and accurate communications and then to support parents in their assimilation of information and decision-making once the results are known.

Maternal investigations also require careful counselling and thought as a constellation of unintended consequences can arise if women do not think through their screening choices, or are inadequately counselled.