Antenatal Flashcards
What is the purpose of the booking visit?
- To determine the mother’s level of risk (low, intermediate, high)
- her status can change at any time
- make sure we can optimise mother’s health
Two types of maternal death
DIRECT (haemorrhage, birthing complications)
INDIRECT (ongoing maternal medical conditions)
Leading cause of indirect maternal death
Cardiac conditions - myopathies in the postpartum period particularly overlooked
Leading cause of direct maternal death
VTE (PE), followed by amniotic embolus then suicide
Worldwide the leading cause is PPH (major obstetric bleeding is >2500mL)
How many appointments do LOW RISK multiparus/nullparous women get?
Booking (10 weeks)
Multiparous (8 appointments) - 16, 28, 34, 36, 38, 40, 41
Nulliparous (10 appointments) -16, 25, 28, 31, 34, 36, 38, 40, 41
What should be checked during each antenatal appt?
Antenatal appointment
- General maternal well being
- Blood pressure
- Urinalysis
- Fetal movements
- Fetal heart rate (auscultate with doppler or pinard’s)
- Measure and plot symphysis - fundal height
What scans will EVERY WOMAN receive and when?
What do they look at?
Every woman will have at least two scans:
- Early pregnancy DATING SCAN: 12 weeks
(Confirm the pregnancy, measure crown-rump length and give a reliable EDD) - ANOMALY SCAN: 20 weeks (look at anatomy e.g. spina bifida/gastroschisis)
Define antenatal anaemia and suggest treatment
This is something that is commonly screened for in pregnancy. Hb levels lower in pregnancy physiologically (number of RBCs increase but plasma increases even more so relative conc is lower) but if they drop <100g/dL then consider FERROUS SULPHATE
Causes of polyhydraminos?
- Maternal diabetes (causing polyuria of foetus)
- Osophageal atresia (unable to swallow fluid)
- Renal problems with baby (2nd and 3rd trimesters baby’s kidneys produce amniotic fluid)
Polyhydramnios presentation
Tight, non-compressible uterus (cannot palpate fetal structures)
High symphysis-fundal height
Polyhydramnios: investigations
USS IS DIAGOSTIC
- amniotic fluid index (AFI)
- more commonly used
- above the 95th decile - maximum pool depth (MPD)
>8cm
Offer regular growth scans and GTT
Polyhydramnios risks
- Increased perinatal mortality
- Increased risk of preterm labour
- Malpresentation (e.g. transverse lie, breech because they have more room)
- CORD PROLAPSE (bigger rush of fluid)
- PPH risk increased
What is routine screening in ante-natal period?
- Fetal anomalies (scan at 20 weeks)
- Infectious diseases (HIV, syphilis, hepatitis B)
- Rhesus negative (prevents rhesus disease of newborn)
- Haemoglobinopathies (sickle cell and thalleseamia)
What is combined screening?
What do they measure?
What do they test for?
What is high risk?
Combined screening
-Optional, offered at the time of the dating scan where crown rump length is measured (from 11 till 14 weeks)
- Nuchal translucency (abnormal if >3.5mm)
- hCG blood test (Human chorionic gonadotrophin)
- PAPPA (pregnancy-associated plasma protein A)
- detection rate of 85%
Tests for:
- Trisomy 21 (Downs)
- Trisomy 18 (Edwards)
- Trisomy 13 (Pataus)
***these will then produce a risk category (high risk = >1/150) NOT DIAGNOSTIC
If combined screening suggests woman is HIGH RISK what is the next stage? (3 options)
High risk combined screening. What next?
1. No further testing
- CVS chorionic villus sampling (from 11w) or
Amniocentesis (from 15w) guided by USS
-1 in 100 diagnostic tests result in miscarriage - Iona blood test (£ and private)
DEFINITIVE tests for DOWN, EDWARDs (18) and PATAUS (13)
What if the woman misses combined screening?
-If the woman attends for her dating scan LATERthan 14WEEKS then it is possible she might miss the window for combined screening, in these circumstances she can be offered QUADRUPLE TESTING
- can be done between 14+2 and 20+0 and involves a blood test only (4 hormones)
- 80% detection rate and 4.1% chance of false positive
Are there other options for antenatal screening beyond those offered?
There is a test known as NON-INVASIVE PRENATAL TESTING (NIPT) that is a blood test that has a very very good detection rate - not offered on the NHS
-Trisomies 13 (patau) +18 (edwards) and 21 (downs)
When does the ANOMALY scan take place and what sort of things does it look for?
Between 18+0 and 20+6 Structural abnormalities including: -Gastroschisis -Spina bifida -Heart defects -Trisomies 13 (patau) +18 (edwards) and 21 (downs)
What infectious diseases are screened for in pregnancy?
- Syphilis
- HIV
- Hepatitis B
HIV in pregnancy - when tested for and what is the risk of transmission?
If woman found, at booking visit, to be HIV +ve then we can act quickly to reduce risk of spread
- Treat mother with antivirals to reduce risk to fetus
- if woman has low viral load risk of transmission is 0.3%, goes up to 3% if breastfeed
Hepatitis B in pregnancy - when tested for and how do we determine risk profile?
Can you breastfeed?
How do we manage?
- Booking bloods
- Notifiable disease - refer to public health
- Breastfeeding is fine
- Baby given extra doses of Hep B vaccine (normal 8,12,16 weeks) PLUS 24 hours/4 weeks/1 year
Syphilis in pregnancy - when tested for ?
How do we manage?
Booking bloods
Will usually be in late-latent phase
Refer to GUM
They need to receive 4 weeks of therapy otherwise the baby will need to receive IV treatment
Other than infectious diseases, what other blood tests are done during booking visit?
Rhesus testing and haemoglobinopathies
Why do we test for Rhesus status?
If the mother is Rh-ve then she could produce antibodies to a rhesus +ve baby meaning all future pregnancies with a Rh+ve baby will be attacked and result in a termination of the pregnancy
Management of a Rh-ve mother
Offer ANTI-D IM injection at 28 weeks and 34 weeks
ALSO WITHIN 72 HOURS of desensitising event (surgery/delivery-can test cord bloods/EC version/heavy PV bleeding)
In what other situations is anti-D given?
Sensitising events
- TOP (termination of pregnancy)
- Miscarriage >12w
- Ectopic pregnancy managed SURGICALLY
- ECV (external cephalic version)
- APH (antepartum heamorage)
- Amniocentesis
What haemoglobinopathies do we test mothers for?
Sickle cell and thalassaemia
- mother will usually be asked to fill out a family origin questionnaire to work out if she is high risk
What is done if the woman is found to have a sickle cell or thalassaemia trait?
- Her partner will be tested
- If high risk>do CVS sampling to determine whether likely to be carrier or affected
- When the baby is born it will have HEEL-PRICK to test haemoglobinopathies
Early symptoms of pregnancy?
Early symptoms of pregnancy
- Amenorrhea
- Nausea +/- vomiting
- Breast tenderness
- Urinary frequency
- Fatigue
- Pelvic pain
- PV bleed
Early signs of pregnancy? When do they occur? (4)
Early signs of pregnancy
- Softening of the cervix (Goodell’s sign); 4-6 weeks
- Bluish discolouration of cervix and vagina due to engorgement of pelvic vasculature (Chadwick sign) 6 weeks
- Uterine enlargement
- Softening of the uterine isthmus (Hegar’s sign)
What are some of the early investigations we can do for pregnancy? When can they be seen? (3)
Investigations of pregnancy -B-hCG ○positive in serum 9 days post conception ○positive in urine 28 days after LMP -Transvaginal or transabdominal USS
What structures appear when during the first trimester or pregnancy?
4-5 weeks - only gestation sac visible. About 6mm long
5-6 weeks - the yolk sac will become visible
6 weeks - the fetal pole should become visible (thickened margin of the yolk sac)
FETUS NOW DOUBLES IN SIZE EVERY WEEK UNTIL 12 WEEKS
6-7 weeks - this should be when you can first hear fetal heart beat although specialist equipment will likely be needed
8 weeks - at this point limb buds will start forming and there will be some fetal movement (women won’t feel it until 18weeks though)
What is mainly happening in the first 12 weeks of pregnancy?
During this period is when ORGANOGENESIS is happening. Cells are differentiating for form the organs
It is during this period that babies are particularly susceptible to teratogenesis
During this time is also when the placenta is forming and taking a major role
What changes are happening in the fetus after 12 weeks?
After 12 weeks the fetus is mostly just growing and developing - lower risk of teratogenesis
What previous obstetric issues (in previous pregnancy) would make the next pregnancy more high risk?
Previous C/S Pre-term delivery Pre-Eclampsia Prev GDM Recurrent miscarriage Still birth Multiple pregnancy SGA Placenta praevia
***would be wanting to ask a lot of questions about how these complicated the pregnancy and how they were managed at the time
How many consecutive miscarriages do you need to have to be classed as worrying?
3 consecutive
With just 1 or 2 there is a 95% chance the next pregnancy will be fine
If a woman has had a previous caesarean section how should she be encouraged to delivery this time?
VBAC
if just one previous C/S consider VBAC
If a woman has had just one previous C/S what are her chances of delivering successfully vaginally?
What about if she’s had a NVD since that C/S?
72-75%
One successful NVD since - 85-90%
What are some benefits of VBAC?
Reduced recovery period, reduced complications and reduced risk of neonatal respiratory problems.
What are some risks of VBAC?
0.5% risk of uterine rupture (2-3x higher if IOL)
25% chance of EmLSCS
1% risk of haemorrhage
1:100 risk of HIE
What are some contraindications for VBAC?
- Previous uterine rupture
- Previous classical uterine incision
- 3 or more prev C/S
How should women considering VBAC be managed?
VBAC discussed early on
Seen back in consultant clinic at 36w for final decision regarding MoD
- If elective LSCS then book for 39 weeks
- If VBAC plan to see at 40-41w if not laboured and consider induction
- Delivery will happen with 1:1 midwife care, in delivery suite with continuous CTG
What are some signs of uterine rupture?
Constant pain, scar tenderness, abnormal vaginal bleeding
What is a HIGH RISK factor for development of VTE in pregnancy?
Personal history of previous VTE EXCEPT one caused by major surgery
How should a woman with HIGH RISK for VTE be managed?
Prophylactic LMWH
4500 tinzaparin
What are some intermediate risk factors for VTE in pregnancy? How’s this managed?
Single, previous VTE related to pregnancy High risk thrombophilia Chronic medical condition Hospital admission Any surgical procedure
Prophylactic dose tinzaparin (4500U) should be considered
What are some LOW RISK factors for VTE in pregnancy?
How many of these should they have before you consider VTE prophylaxis?
BMI >30 Age >35 Parity 3 or more Smoker Gross varicose veins Current pre-eclampsia Immobility FH Low risk thrombophilia Multiple pregnancy
MUST HAVE 4 OR MORE FOR LMWH FROM FIRST TRIMESTER
IF WOMAN HAS 3 RISK FACTORS SHE WILL REQUIRE LWMH FROM 28 WEEKS
If a woman has been on LMWH during her pregnancy how will she be followed up?
She will need to continue on LMWH for 6 weeks post-natally
What is gravity?
GRAVITY
- Total number of pregnancies at any gestation; current pregnancies, abortions, ectopics
- Twins count as one pregnancy
What is Parity?
PARITY
- Number of pregnancies that have been carried to >20 weeks
- Twins count as one
- Grand multiparity is parity of 4 or more
What is the parity and gravitidity for a woman who has had 2 children, one miscarriage and is pregnant again
Para 2+1 Grav 4
Definition of normal pregnancy term?
Normal pregnancy term: 37-42 weeks
Miscarriage vs. stillborn
Miscarriage: loss of intrauterine pregnancy before 24 weeks
Stillbirth: loss of intrauterine pregnancy after 24 weeks
Explain the 1st, 2nd 3rd trimester.
First trimester: 0-12 weeks
Second trimester: 12-28 weeks
Third trimester: 28-40 weeks
Cardiovascular effect of pregnancy?
Cardiovascular effect of pregnancy
- Increased CO, HR, and blood volume
- Decreased BP
- Enlarging uterus compresses IVC and pelvic veins risking hypotension, varicose veins, haemorrhoids, leg oedema
Haematological effect of pregnancy? (hemoglobin, WCC, platelets, clotting factors)
Haematological effect of pregnancy
-Decrease in haemoglobin and haematocrit due to haemodilution - plasma volume increases more than RBC mass
-Increased leukocyte count
-Gestational thrombocytopenia
-Increased risk of DVT and PE (hypercoagulable state)
○ Increase in factors I, VII, VIII, IX, X, XII
○ Decrease in XI, XIII and antithrombin III activity
- Venous stasis from uterine compression
Respiratory effect of pregnancy? (oxygen capacity, CO2 sensitivity, minuet ventiliation, tidal volume, total lung capacity, functional residual capacity, residual volume, vital capacity)
Respiratory effect of pregnancy
- Increased O2 consumption by 20%
- Increased sensitivity to CO2 - the progesterone effect on the respiratory centre (causing hyperventilation and respiratory alkalosis compensated by increased renal excretion of serum bicarbonate)
- Increase in minute ventilation (50%) and tidal volume (33-50%)
- Decreased TLC, FRC and RV
- VC (total expired after full inhalation) unchanged
GI effect of pregnancy?
GI effect of pregnancy
- Increased GORD - decreased sphincter tone, delayed gastric emptying, increased intra-abdominal pressure
- Increased stasis in gallbladder
- Decreased GI motility and constipation
- Upward displacement of the appendix (appendicitis may have atypical presentation)
- Haemorrhoids caused by constipation and elevated venous pressure
GU effect of pregnancy? (4)
GU effect of pregnancy
-Increased GFR by 50%
-Glycosuria
-Increased urinary frequency
-Physiological dilatation of ureters and renal pelvis
Increased incidence of UTI and pyelonephritis
Endocrine effect of pregnancy? (oestrogen, progesterone, HCG, Thyroid, cortisol, prolactin, relaxin, calcium)
Endocrine effect of pregnancy
OESTROGEN- estradiol
· Production requires maternal, placenta and fetal contributions (sudden decline may indicate fetal compromise)
PROGESTERONE
-produced by corpus luteum in first 7 weeks, then placenta takes over and maintains the endometrium
HCG
- produced by placental trophoblastic cells and maintains the corpus luteum
- levels below expected dates may indicate ectopic, miscarriage or wrong dates
- levels higher than expected is multiple gestation, molar pregnancy, trisomy 21 or wrong dates
THYROID
-moderate enlargement and increased basal metabolic rate
CORTISOL
-Increased maternal cortisol
PROLACTIN
-increasing oestrogen causes response by pituitary , stimulation of lactation
RELAXIN
-produced by ovary and relaxes pelvic joints and cervix
CALCIUM
- Total maternal calcium decreased (due to decreased albumin)
- Free ionised levels remain the same due to increased PTH> bone resorption and gut absorption (no symptoms of hypercalceamia)
- Bone turnover increase but no loss of bone density (oestrogen counteracts PTH by inhibiting resorption)
Neuro effect of pregnancy?
Neuro effect of pregnancy
-Increased incidence of Bell’s palsy and carpal tunnel
Skin effects of pregnancy?
Skin/pigmentation effects of pregnancy
- Straie gravidarum (atrophic linear scars- connective tissue changes)
- Pigmentation changes (areola and perineum)
- Linea nigra (midline abdominal pigmentation)
- Spider naevi
- Palmar erythema
