Obstetrics Antepartum Care Flashcards
Define gravidity
How many times a woman has been pregnant (regardless of outcome)
Define parity
How many babies a woman has delivered at 24+ weeks gestation
a = alive or still birth b = losses before 24 weeks parity = a + b
Define primigravid
First ever pregnancy
Define nulliparous
Has had no delivery of a baby >24 weeks gestation
Define multiparous
Has had one of more deliveries of babies >24 weeks
How is pregnancy dated in relation to conception?
Conception is 2 weeks after 1st day of LMP with a regular 28 day cycle
How are the three trimesters split?
1st trimester = 1-12 weeks
2nd trimester = 13-27 weeks
3rd trimester = 28 weeks - delivery
What is the puerperium period?
Delivery and the following 6 weeks
reversal of the physiological changes in pregnancy
How is EDD calculated based on LMP?
Add 9 months + 7 days to 1st day of LMP
Pregnancy lasts 38 weeks from conception/40wks from 1st dat LMP
How is a pregnancy dated during:
6-12 weeks
14-20 weeks
6-12 weeks = crown-rump length
14-20 weeks = biparietal diameter (BPD)
A woman who books in for the first time in 3rd trimester needs two growth scans two weeks apart
What the 1st antenatal (booking) visit?
When is it done?
A pregnant patient is seen by a midwife, risk assessment, decided if it is midwife/GP care vs consultant lead care
Book by 12 weeks (or within 2 weeks if >12wk gestation)
What are the first antenatal bloods done at a booking visit? (6)
Routine:
1) FBC - check for anaemia (<110g/l)
2) Haemoglobinopathies
- sickle cell anaemia
- thalassaemia
3) Rhesus status and Ab
4) Blood group
Infection screen:
5) HIV (opt out test)
- mothers need to be on anti-retrovirals to ensure load undetectable at 36 weeks
- baby has medication for 4 weeks after to reduce HIV risk to 1%
6) Hep B
- receive vaccination at birth if born to +ve mother
7) Syphilis
- mother needs to have received full treatment 4 weeks priorate delivery otherwise baby has to have IV treatment
What health advice is given at a booking visit?
Diet eg avoid unpasteurised products like soft cheese / fish high in mercury like swordfish Smoking cessation Alcohol Folic acid - ideally preconceptual Vit D
When can an US detect a pregnancy?
Approx 5wk gestation
When are early pregnancy scans and what can they determine?
<11wk
Location, viability and dating of pregnancy
List some indications for an early pregnancy scan
Bleeding, pain or hyperemesis gravid (to exclude a molar pregnancy)
What antenatal visits are routine for a healthy pregnant woman who is nulliparous?
10 antenatal visits
Booking (8-10 weeks) then: 16, 25, 28, 31, 34, 36, 38, 40, 41
What antenatal visits are routine for a healthy pregnant woman who is multiparous?
8 antenatal visits
Booking (8-10 weeks) then: 16, 28, 34, 36, 38, 40, 41
When are foetal movements usually felt?
“Quickening” = 16-25 weeks
In first pregnancy this can be closer to 25 weeks, by the second can be as early as 13 weeks
Outline visits:
28, 34, 36, 40, 41 weeks
28: Hv and Rh antibodies (anti-D if needed)
34: discuss labour, birth and pain relief
36: discuss breast-feeding, neonatal vit k, postnatal care, postnatal depression
40: discuss post-dates pregnancy
41: offer membrane sweep and book IOL by 42wk
When is the Combined Test and what does it measure?
11+0 to 13+6 weeks (scan and blood test)
US (nuchal) scan measurement of subcutaneous tissue between the skin and soft tissue of overlying cervical spine with fetus in neutral position
Maternal bloods
- hCG
- PAPP-A
Get early result
What is the detection rate of the Combined Test and what three syndromes does it test for?
Detection rate 85%
Test for trisomy’s:
Down’s syndrome (Chr 21)
Edwards syndrome (Chr 18)
Pautaus syndrome (Chr 13)
How sensitive is the combined test?
85%
When is the Quadruple Test and what does it measure?
For women who book later in pregnancy - between 15+0 and 20+0. Uses a dating scan (not NT scan) and maternal bloods:
Maternal bloods:
- AFP
- hCG
- Oestriol
- Inhibin-A
What is the significance of a raised serum AFP (Alpha fetoprotein)?
AFP prduced by fetal liver, elevated in open NTD, exomphalos, teratomas, Turner’s syndrome
What is pregnancy-associated plasma protein A (PAPP-A)?
A large glycoprotein produced by placenta involved in matrix materialisation and angiogenesis
- Low levels = poor early placentation
- Low levels in 1st trimester screening associated with trisomies 18 and 21, pre-eclampsia, growth restriction and preterm delivery
What is the integrated test?
A better screening test than the combined test but is expensive and rarely used. Involves:
- NT + PAPP-A in first trimester
- Quadruple test in 2nd trimester
What are screen positive women?
Risk of 1 in 150 or more is regarded as ‘positive’
Offer invasive screening - CVS or amniocentesis