ANTENATAL CARE
Antenatal care aims to optimize the health and well-being of mother and baby, and to detect and treat any abnormal events in pregnancy. Antenatal care may be provided by the GP, midwife (in hospital or in the community) or the obstetrician teamAt all visits, the woman should be encouraged to discuss her concerns and any minor disorders of pregnancy, discuss tests and their results, and have her blood pressure and urinalysis checked.
In the second trimester growth is assessed by measurement of symphysis–fundal height (SFH) and from 36 weeks, presentation is clinically assessed by palpation. Antenatal visits also provide an opportunity to discuss the forthcoming delivery and the woman’s birth plan
Factors at booking indicating referral for obstetric or senior midwifery review
Age over 40 years or under 19 years Body mass index ≥35 or< 18 Kg/mr2
Grand multiparity (more than three pregnancies)
Conditions such as hypertension, cardiac or renal disease, endocrine, psychiatric or haematological disorders, epilepsy, diabetes, autoimmune diseases, cancer, human immunodeficiency virus (HIV)
Previous caesarean section or other uterine surgery
Previous postpartum haemorrhage
Severe pre-eclampsia or eclampsia Previous pre-eclampsia or eclampsia
Three or more miscarriages Previous preterm birth or mid-trimester loss
Previous psychiatric illness or puerperal psychosis
Previous neonatal death or stillbirth Previous baby with congenital abnormality
Previous small for gestational age (SGA) or large for gestational age (LGA) infant
Family history of genetic disorder
Woman with uncomplicated first pregnancy should visit 10 times , women who have had previous uncomplicated pregnancies seven times. Typical timing of antenatal visits, which might be with GP, midwife or obstetrician, for a nulliparous woman are outlined below.
Booking (6–12 weeks)
A medical, gynaecological, obstetric, family and social history should be taken. Drugs and allergies are recorded. Examination should include height and weight, and calculation of BMI. Booking blood pressure must be recorded. Breast or pelvic examination is not indicated and should never be performed in the antenatal setting without a specific indication and informed consent from the woman, with a chaperone present. One such indication for pelvic examination is in a woman with a history of female genital mutilation, who may need early referral to a specialist clinic for antenatal de-infibulation, and a management plan made for delivery.
First-trimester scan should be arranged to confirm dates and screen for Down’s syndrome. If the woman presents after 14 weeks a scan should be arranged to confirm gestation (by biparietal diameter or head circumference) and serum screening for Down’s syndrome offered.
Urine should be checked for proteinuria and a midstream urine sample sent to screen for asymptomatic bacteriuria.
Booking blood tests should be taken.
The woman should be referred to an obstetrician if indicated from the previous history.
Information should be given on diet, smoking, alcohol, exercise (see prepregnancy counseling, above) and antenatal care.
Booking blood tests
l Full blood count: to exclude anaemia.
l Group and antibody check: to detect Rhesus-negative women and atypical antibodies.
l Haemoglobinopathy screen: this may be checked in all women or used selectively for those of Afro-Caribbean, Mediterranean or Asian origin. Those with positive results should be offered counselling and partner testing followed by antenatal diagnosis for at-risk fetuses.
l Rubella: to check immunity and plan postnatal vaccination for those with low-level or no immunity.
. l Syphilis: to check for syphilis antibodies
l Hepatitis B:
l HIV: HIV-positive women should be referred to GUM physicians, offered counselling and given antiviral agents prior to delivery.
16 weeks
All results from the booking visit should be given and explained. Anaemia should be treated if necessary. Blood pressure and urine should be checked.
25 weeks
The result of the anomaly scan should be reviewed. Blood pressure and urine should be checked and SFH recorded. Fetal movements should be asked about (usually felt at 18–20 weeks in nulliparous, 16–18 weeks in parous women). Fetal heart beat should be checked with Doppler or Pinnard stethoscope. 28 weeks
Blood pressure, urine and SFH should be checked. Fetal movements should be asked about and fetal heart auscultated. Repeat screen for anaemia by full blood count, and an antibody screen should be sent (regardless of Rhesus status).
Anti-D should be given to Rhesus-negative women.
31 week
s Blood pressure, urine and SFH should be checked. Fetal movements should be asked about and fetal heart auscultated. Iron should be commenced if haemoglobin is less than 10.5g/dl.
34 weeks
Blood pressure, urine and SFH should be checked. Fetal movements should be asked about and fetal heart auscultated. A second dose of anti-D should be given to Rhesus-negative women.
36 weeks
Blood pressure, urine and SFH should be checked. Fetal movements should be asked about and fetal heart auscultated. The position of the baby should be assessed clinically and external cephalic version recommended and arranged if breech. If the placenta was low at 20 weeks then the repeat scan should be reviewed for placental site.
38 weeks
Blood pressure, urine and SFH should be checked. Fetal movements should be asked about and fetal heart auscultated. Fetal position should be checked.
40 weeks
Blood pressure, urine and SFH should be checked. Fetal movements should be asked about and fetal heart auscultated. Fetal position should be checked.
41 weeks
Blood pressure, urine and SFH should be checked. Fetal movements should be asked about and fetal heart auscultated. The fetal position should be checked. Membrane sweep should be offered and recommended and a plan made for induction of labour.
For parous women the 14-, 25- and 31-week visits can be omitted unless specific factors indicate that an extra visit is needed.
Some women will need obstetric-led care and the timing of these visits should be tailored to the specific problem. For example, a diabetic woman may need to be seen by the hospital team every 2 weeks throughout the pregnancy,
whereas a woman with a previous caesarean section who plans a vaginal birth in this pregnancy may see the obstetrician once and then be referred back to her midwife for the rest of her antenatal care.
Some women should have antenatal care within a multidisciplinary team. These would include those with diabetes, cardiac or renal disease.
Rhesus disease and other red-cell alloimmune antibodies
All women should have their blood sent for group and antibody screen at booking as 15% are Rhesus-negative (they do not carry the Rhesus D antigen on their red blood cells).
These women are, therefore, at risk of developing anti-D antibodies to a Rhesus-positive fetus.
This would not usually occur in a first pregnancy unless sensitization had occurred previously, for example from a blood transfusion.
Potentially sensitizing events in the pregnancy include:
l Threatened miscarriage, miscarriage, ERPC or ectopic pregnancy l Trauma to the abdomen, such as amniocentesis, CVS or road traffic accident l External cephalic version l Abruption or other antepartum haemorrhage l Delivery, especially if multiple pregnancy or manual removal of placenta l Spontaneous fetomaternal haemorrhage.
The rate of sensitization has reduced to 1.5% by the use of anti-D at delivery and at potentially sensitizing events. However, it is estimated that this rate will reduce to 0.3% if routine anti-D prophylaxis is given to all Rhesus-negative women at 28 and 34 weeks as well as at delivery.
Antenatal education
First-time mothers and their partners should be encouraged to attend antenatal classes. These provide information for couples on pregnancy, childbirth and parenting. Topics include the physical and psychological changes in pregnancy, the stages of labour, analgesia in labour, what can go wrong in labour, breastfeeding, the postnatal period and caring for a newborn baby. Classes are thought to reduce anxiety in parents and provide a social interaction with other parents-to-be, though evidence is lacking over whether there is any effect on birth outcomes.