Antenatal Screen and Dating scan

Dr Emeil KamelVMO Norwest private Hospital

Staff Specialist Blacktown HospitalSeptember 2011

Pre-pregnancy Counselling and routine Antenatal Assessment in the absence of pregnancy complications

RANZCOG College Statement, C-Obs 31st Endorsed: July 1992Current: November 2009

Pre-Pregnancy Counselling

Purpose Assessment of any conditions of relevance and

optimising any treatment with respect to the forthcoming pregnancy (Diabetic, Ht, etc..)

Obtaining general advice regarding personal health care in early pregnancy, in particular, stop smoking, medications, alcohol, X-rays … etc

The following investigations are recommended: Rubella immunity status Varicella immunity status (if unknown) Cervical smear (if clinically appropriate)

All women planning pregnancy should receive advice with respect to:

Where and when to attend in early pregnancy Vitamin supplementation (particularly folic acid for

3 months preconception) Models of care

First Antenatal Visit All women should be advised to attend in

early pregnancy with a view to:

Confirming pregnancy and establishing an EDC

A comprehensive clinical assessment in order to determine any clinical conditions that may be of relevance to the pregnancy

Obtaining general advice regarding common issues of concern in early pregnancy and management of the pregnancy

Clinical Assessment A careful medical history and thorough clinical

examination. The following investigations are recommended

(in the absence of specific complications):

Full blood examination Particular note should be taken of the MCVas a potential

indicator of an underlying Haemoglobinopathy

Blood group and antibody screen Where the blood group has already been performed it

does not need to be repeated. However, the antibody screen should be repeated at the beginning of each pregnancy.

Rubella antibody status All women should have their rubella antibody titre measured for

each pregnancy.

There is evidence that levels may decline, particularly following immunization as compared to natural infection.

Syphilis serology

Syphilis testing should be performed by screening with a specific treponema pallidum assay for example Treponema pallidum haemaglutination assay (TPHA) or the Treponema pallidum particle assay (TPPT). The non-specific Treponema pallidum assays, such as rapid plasma reagin (RPR) test, although cheaper, are less likely to pick up latent infection.

All pregnant women need appropriate counselling as to the limitations of screening for viral infections in pregnancy and the implications of both positive and negative findings.

HIV All pregnant women should be recommended to have HIV

screening at the first antenatal visit

Hepatitis B serology All pregnant women should be recommended to have Hepatitis

B screening in pregnancy.

Hepatitis C serology All pregnant women should be recommended to have Hepatitis

C screening in pregnancy.

Varicella Consider when there is no history or uncertain history of

previous illness.

Midstream urine Examination by MCS

Cervical cytology A cervical (Pap.) smear should be recommended at the first

antenatal visit if this would fall due during the pregnancy (The

national cervical screening program) There is no evidence to suggest that a Pap smear in pregnancy

is harmful. Pap smear can be taken ideally before 24 weeks gestation.

Other tests

HaemoglobinopathiesVitamin DCMV

Screening for Haemoglobinopathies

As a minimum, all women should be screened with MCV and MCHC.

Haemoglobin electrophoresis and iron studies (ferritin) should be performed when MCV <80fL or MCHC <27pg

Testing of normal-MCV women for haemoglobinopathies may be considered if they are members of high-risk groups. Southern European, Middle Eastern, African, Chinese, South East

Asian, Indian subcontinent, Pacific Islander, New Zealand Maori, South American

Vitamin D

There is a recognised re-surgence of rickets amongst our population

Vitamin D deficiency causes significant morbidity to both mother and baby

It is crucial that women at risk for vitamin D deficiency should be tested in early pregnancy and provided with vitamin D supplementation.

Actions of Vitamin DOrgan Action

Bone Bone formation (maintain Ca and PO4 concentration)

Intestine Enhance Ca absorption

Kidneys Decrease Ca and PO4 excretion

Immune System Stimulates anti-tumour activityDecreases risk of auto-immune disorders

Parathyroid Glands Inhibits PTH secretion

Pancreas Stimulates insulin production

Aetiology of Vitamin D deficiency Inadequate direct exposure to sunlight

5-15 minutes 3 times/week direct sunlight

Increased skin pigmentation Dark skin requires 6 times the sun exposure to achieve

same increase in vitamin D Diet

Recommended daily adult intake is 600IU/day (Average adult intake 50-100IU)

Prolonged breastfeeding Breast milk contains 25IU/litre vitamin D Recommended daily infant intake is 200IU/day (8L

breast milk/day!) Reduce synthesis or increased degradation

Liver or Renal disease Drugs: rifampicin, isoniazide and anti-convulsants

Features of Vitamin D deficiency Osseous signs

Rickets and osteomalaciao Genu varum (bowed legs), genu valgum (knock-knees),

knee deformitieso frontal bossingo Limb pain and fractureso Hypocalcaemia: seizures, carpopedal spasmo Delayed fontanelle closureo Delayed tooth eruption

Non-Osseous signs Dilated cardiomyopathy Marrow fibrosis: pancytopenia

Relevance to Western Sydney

Greater Western Sydney (GWS) Area; the first point of arrival of largest refugee and migrant population in Australia

2 million people (10% total Australian population) live in the GWS area

Over 200 nationalities represented

Retrospective descriptive study (1993 – 2003)

126 cases of vitamin D deficiency and rickets in children at Sydney Children's Hospital at Westmead Sydney Children’s Hospital St. George Hospital.

Median age presentation 15 months (25% <6 months)

Most common presenting features Hypocalcaemic seizures(33%) Bowed legs (22%)

Steady increase in number of cases per year, with a doubling in cases from 2002-2003

79% of cases were born in Australia or recently migrated children

Region of origin predominantly Indian subcontinent(37%) Africa(33%) The Middle East (11%)

Vitamin D deficiency amongst pregnant women at Westmead Prospective study of vitamin D levels amongst 313

pregnant women attending antenatal clinic at Westmead Hospital between June-August 2008

Serum concentrations of 25-OH-vitamin D were added to routine antenatal screen

Women were grouped according to country of birth 39% Australia 23% Indian Subcontinent 17% south East Asia 9% Middle East 5.1% Europe 4.5% New Zealand/Pacific Islands 2.5% Africa

Vitamin D levels defined: Severe deficiency: <37nmol/L Moderate deficiency: 37-49 nmol/L Mild deficiency: 50-79 nmol/L Sufficient: 80-130 nmol/L

Australian Born (n=123)

0

10

20

30

40

50

60

70

80

<37 37-49 50-79 >80

Indian Subcontinent (n=71) Africa (n=8)

0

5

10

15

20

25

30

<37 37-49 50-79 >800

1

2

3

4

5

6

<37 37-49 50-79 >80

South East Asia (n=54) Middle East (n=27)

Europe (n=16) NZ/Pacific Islands (n=14)

0

5

10

15

20

25

30

<37 37-49 50-79 >80 0

2

4

6

8

10

12

<37 37-49 50-79 >80

0

1

2

3

4

5

6

7

8

9

<37 37-49 50-79 >80 0

1

2

3

4

5

6

7

8

9

<37 37-49 50-79 >80

Vitamin D Levels<37(Severe deficiency)

37-49(Moderate deficiency)

50-79(mild deficiency)

80-130(sufficient)

Australia 7% 15% 67% 11%

Indian Subcontinent

44% 34% 21% 1%

SE Asia 9% 20% 54% 17%

Middle East 21.5% 30% 43% 5.5%

Europe 6.5% 12.5% 53% 28%

NZ/Pacific islands

5% 13% 69% 13%

Africa 69% 6% 19% 6%

Recommendations

Prevention and treatment of infant and childhood vitamin D deficiency in Australia and New Zealand: a consensus statement. MJA.vol 185;5: 268-272.2006

Recommendations

Dark-skinned or veiled pregnant women should be screened and treated for vitamin D deficiency, and their breastfed infants should be supplemented with vitamin D for the first 12 months of life.

At risk children should receive 400IU vitamin D daily, if compliance is poor, an annual dose of 150 000IU may be considered.

Treatment of vitamin D deficiency is with cholecalciferol for 3 months: 1000 IU/day if < 1 month of age 3000 IU/day if 1-12 months of age 5000 IU/day if> 12 months of age

CMV

Screening for CMV infection in pregnancy is currently not recommended as a routine. Relatively low risk of infection Low rate of possible damage to the fetus

95% of congenital CMV have no sequelae and half of these cases are restricted to hearing loss- termination is not recommended

No effective therapy is available to infected infants Antiviral agents (acyclovir and ganciclovir) do not decrease risk

of vertical transmission.

Seroprevalence in Australia is about 50%

Risk of seroconversion during pregnancy in seronegative women Generally approx 2% Day care workers - 11% seroconversion / year Parents with child in day care - 30% seroconversion / year

Prevent primary infection during pregnancy Minimize exposure in high-risk areas (many kids). Careful hand-washing

Dating Scan

All women should be offered a dating scan NT scan EDC (decrease IOL) Ectopic, Twins

Live intrauterine pregnancy B-HCG 1500, Sac seen with TV B-HCG 5000, Sac seen with TA

High B-HCG with no intrauterine pregnancy Suspect ectopic But Twins and molar pregnancy

Normal Intrauterine gestation

By 5 weeks gestational, a double decidual sac sign

By 5.5 weeks , a yolk sac is usually visualized (5-6 mm). Involute by 11 weeks

By 6 weeks, an embryonic pole should be identifiable

By 6.0 to 6.5 weeks, cardiac activity should be visualized on real-time Imaging

Corpus Luteum

Forms from the ovarian follicle after ovulation.

Secretes progesterone to maintain the pregnancy until the placenta assumes this role.

Wide range of appearances: Ill defined, hypoechoic, homogeneous structure A thick-walled cystic structure A complex cystic lesion with internal echoes

Sonographic appearances of the corpus luteum Cystic Complex cystic lesion with thick wall

Abnormal intrauterine gestation

The literature reports that there should be a yolk sac with MSD >8 mm an embryo with MSD >16 mm cardiac activity by the time the embryo is 5 mm in length or

MSD >18 mm

Distorted non ovoid contour

Location in the lower uterine segment

Gestational sac (MSD = 2.2 cm, 7 wk gestation) without evidence of yolk sac or fetal pole. The sac has a distorted non-ovoid contour with a thin decidual reaction

Distorted enlarged gestational sac with debris and membranes extending from the lower uterine segment into the cervix

Ectopic pregnancy

When a pregnancy test is positive and there is no evidence for an IUP, any adnexal finding should be considered suspicious for an ectopic pregnancy until proven otherwise

Findings Live embryo in an extrauterine gestational sac Adnexal mass with yolk sac or nonliving embryo Complex or solid adnexal mass Hemoperitoneum (nonspecific finding as other conditions can

cause ruptured hemorrhagic corpus luteum cyst, spontaneous abortion)