SASUOG

South African Society for Ultrasound
in Obstetrics and Gynaecology

For Patients

The Maternal Fetal Medicine Services in South Africa


The discipline of Maternal and Fetal medicine has seen major advances over the past two decades. The combination of good imaging technology, the advances in biochemical testing and the increased and continuous acquisition of knowledge and expertise in the field of Ultrasound and Fetal medicine has elevated the standard of care in the various centers of excellence in Maternal and Fetal medicine around the world to near-perfect. The use of this knowledge has enabled doctors and prospective parents to use prevention, prophylaxis, diagnosis and treatment of a number of conditions that would otherwise have a disastrous outcome, to their advantage.

The screening, diagnosis and management of aneuploidies in the first trimester have revolutionized the way of thinking in both health care providers and parents. The measurement of the Nuchal Translucency, together with the assessment of the fetal anatomy and the first trimester biochemistry can provide us with very accurate results with regards to aneuploidy screening.

Prospective parents don’t have to agonize for weeks before they know whether there is anything wrong with their baby. Within 45 minutes and during one single consultation, the couples whose babies screen positive for chromosomal abnormalities are offered counseling and a diagnostic test (Chorionic Villus Sampling or Amniocentesis). The first results can be ready within 72hours.

At the same time, during the same consultation, the entire anatomy of the fetus is assessed. Depending on the patient’s history, conditions that may have serious effects later in pregnancy such as preeclampsia or later in life such as genetic conditions are screened for.

The challenges we are facing in South Africa are mainly due to shortage of resources in the public sector. Funds are usually channeled to other areas of medical importance such as the HIV/AIDS pandemic. Shortage of nursing and medical personnel makes the situation even more challenging. Putting effective screening programs in place to cater for the entire South African pregnant population is the only way forward.

Adequate screening programs, designed to benefit the entire population, will eventually result in reducing the number of unnecessary routine antenatal visits, reduce the number of unnecessary invasive procedures, result in decongestion of the public hospitals, and in addition help reduce the number of undiagnosed or misdiagnosed congenital abnormalities.

Screening programs and management protocols, not only save lives, they also save the country money in the long term.

The cost of clinical negligence in South Africa has risen by 132% in the past two years.
The Department of Health in Gauteng paid R44million in litigations in 2011. Currently R1.6 billion in claims are pending against the Gauteng Department of Health.

In 2011 MPS (Medical Protection Society) settled the highest yet claim of R24million for a neurological claim (after birth). Obstetricians paid R76130 in 2006, R187830 in 2011 and R220700 in 2012 for medical insurance.

In many European countries, these programs are already in place, with great success.

Education and training of medical personnel to offer this type of screening in all major hospitals is essential. The government’s assistance and involvement as a major stake holder is necessary to help put this infrastructure in to place.

This short review is aimed for specialists and subspecialists in Obstetrics, Gynaecology and Maternal and Fetal Medicine, registrars, sonographers, and anybody else who has an interest in Obstetrics and Obstetric Ultrasound.

Routine scanning, should be offered as a baseline investigation, to all obstetric patients seen in the antenatal clinics, private practices and to patients referred for specific problems.

Click here to download the Fatal Assessment Center leaflet

THE ULTRASOUND SCAN AT 11 TO 14 WEEKS

Ideally, all pregnant women should have their first scan between 11 and 14 weeks.

The purpose of the first trimester scan is
1. To date the pregnancy accurately
This is particularly relevant for women who cannot recall the dates of their last menstrual periods or who have irregular cycles. By measuring the fetal crownrump length, the gestational age can be accurately calculated.
2. To diagnose major fetal anomalies
In about 1% of pregnancies the fetus has a major abnormality that may be visible at the 11-14 week scan. These abnormalities may be incompatible with life or may be corrected by surgery before or after birth.

3. To calculate the risk for chromosomal abnormalities
All women, of whatever age, have a chance of delivering a baby with chromosomal abnormalities, e.g. Down’s syndrome. The risk of a chromosomal abnormality is calculated from the maternal age (MA), gestational age, fetal nuchal translucency (NT), and presence or absence of the nasal bone (NB). Assessment of (MA + NT + NB) gives a detection rate of 92%. Addition of serum PAPP-A (pregnancy-associated placental protein A) and free beta-hCG may improve the detection rate. Women with either increased Nuchal Translucency or increased overall risk are counseled for possible chorion villus sampling or amniocentesis.

4. To determine the risk for pre-eclampsia
Increased resistance in the uterine arteries detected by Doppler velocimetry, suggests an increased risk for development of pre-eclampsia. A reduced PAPPA serum level is another indicator.

5. The determine the risk of preterm labour
The measurement of the cervical length in the first trimester enables the calculation of a risk of preterm labour before 34weeks.

6. To diagnose multiple pregnancy

Approximately 2% of natural conceptions and 10% of assisted conceptions result in multiple pregnancies. Early ultrasound scanning can determine chorionicity, and help plan future antenatal care, mode and timing of delivery

7. To diagnose early pregnancy failure
In about 3% of women an early pregnancy failure (missed abortion) can be identified.

THE ULTRASOUND SCAN AT 18-23 WEEKS


Irrespective of the outcome of the 11-14 week scan, if the pregnancy continues, another scan at about 20 weeks is recommended to identify structural abnormalities. This is particularly important in fetuses with increased Nuchal Translucency with normal karyotype at the 11-14 weeks scan, because of the higher risk of cardiac abnormalities and rare genetic syndromes. In addition the assessment of the feto-maternal circulation and the cervical length continue to provide information with regards to the well being and prognosis of the pregnancy.

Down’s syndrome detection and screening from 15 to 23 weeks

1. Biochemical screening

Maternal serum levels of hCG, unconjugated estriol, and alphafeto-protein (triple test) and inhibin-A (quadruple test) may be measured to compute a Down’s syndrome risk at 16-18 weeks. Women with ‘positive’ tests are counseled for possible amniocentesis. These tests are currently not done in public hospitals and the first trimester screening programme is significantly more accurate.

2. Ultrasound detection of ‘soft markers’
What is a “soft marker”? A Soft marker is structural anomaly visible on ultrasound scan rarely of postnatal significance but associated with a chromosomal abnormality

The presence of one or more of the following markers on ultrasound scan may provide evidence of a possibility of Down’s syndrome in that fetus:

Cardiac abnormalities,
Renal pyelectasis,
Short femur,
Short humerus,
Sandal gap,
Hypoplasia of the middle phalanx of the fifth finger and cleinodactyly, Nuchal fold thickening.
Women with fetuses showing these features may be counseled for possible amniocentesis.

3. Structural abnormalities or ‘hard markers’
Ultrasound scanning may demonstrate serious structural abnormalities which are frequently associated with Down’s syndrome (and other chromosomal abnormalities).

These include duodenal atresia, omphalocele, cystic hygroma, hydrothorax, atrial septal defect, ventricular septal defect, and cerebral ventriculomegaly. Fetal karyotyping using amniocentesis or cordocentesis is recommended.

Pregnancies requiring referral to the Fetal Medicine Unit

The table shows categories of patients who may be referred to a Fetal Medicine Unit for specialist opinion genetic counseling, detailed ultrasound scanning, and invasive tests if required.

Referrals should be made as early as possible in the pregnancy, to allow time for counseling and decisions, and for early diagnosis of any disorders.

Risk factors for genetic disorders and birth defects


Women at risk

Tests

Advanced maternal age (≥40 years)Ultrasound
CVS
Amniocentesis
Three or more first trimester miscarriages Parental blood
Ultrasound
Amniocentesis
Previous child with a genetic disorder/birth defect, or family members affected by a specific genetic disorder.Ultrasound
CVS
Amniocentesis
Cordocentesis
Exposure to teratogen drugs or toxins during pregnancy, e.g. warfarin, retinoids, alcohol, antiepileptic drugs, lithiumUltrasound
Maternal infection during pregnancy Maternal blood
Ultrasound
Cordocentesis
Maternal illness e.g. pregestational diabetes mellitus, congenital heart condition Ultrasound
Couples in consanguineous relationships and women from ethnic groups at high risk for specific recessive disorders, e.g. Ashkenazy Jews (Tay-Sachs), Greeks and Cypriots (beta-thalassaemia) and Central Africans (sickle cell disease) Parental blood
CVS
Amniocentesis


Amniocentesis is best performed at 15-23 weeks gestation, and Chorion Villus Sampling (CVS) at 11-14 weeks.

POSTNATAL INVESTIGATION

Where a genetic condition or birth defect is suspected, the following steps should be followed to obtain a diagnosis so that appropriate postnatal counseling may be provided about risks of recurrence of the condition in a future pregnancy. History and basic external examination

  • Obtain a full pregnancy history
  • Obtain a full family history
  • Ask about possible exposure to teratogens
  • Note whether there was oligohydramnios or polyhydramnios
  • Record head circumference, weight, length, right foot length, and all abnormal external clinical features
  • With the mother’s consent, take photographs to show all the clinical features clearly
Special investigations
  • Always check or repeat syphilis serology (RPR)
  • Take photographs and a full body x-ray (babygram)
  • If the baby is alive, send blood for karyotyping
  • If the baby is dead, send heparinised blood from the heart, or skin (full thickness, in sterile saline, submitted within 48 hours) for karyotyping
If possible, request an autopsy for suspected cardiac and renal disorders, and for all multiple congenital anomaly syndromes in which a definitive postnatal diagnosis cannot be confirmed following the steps above.

LIST OF WELL KNOWN TERATOGENS

Maternal infections
Syphilis
Toxoplasmosis
Rubella
Cytomegalovirus
Herpes simplex type 2
Human parvovirus B19

Maternal medical conditions
Insulin dependent diabetes mellitus
Epilepsy
Hypothyroidism
Hyperthyroidism
Systemic lupus erythematosus
Phenylketonuria

Drugs/chemicals/radiation
Ethyl alcohol
Cocaine
Warfarin
Anticonvulsants: phenytoin, carbamazepine, valproic acid
Antineoplastic drugs: methotrexate, cyclophosphamide, aminopterin
Tetracyline
Diethylstilbestrol
Lithium
Retinoids
X-Ray radiation in large doses
Heavy metals: mercury, lead



Prof Ermos Nicolaou
Wits Maternal and Fetal Medicine Centre
Morningside Clinic and Chris Hani Baragwanath Hospital
University of the Witwatersrand
e-mail: Ermos.Nicolaou@wits.ac.za