Numbers to Memorise Flashcards
Clotting factors that increase during pregnancy
All except factor 11 and 13
A healthy 32 year old woman is found to have gestational diabetes at 28 weeks of gestation. What is her risk of developing type 2 diabetes over the next 10 years?
50%
Risk of recurrence of preeclampsia?
15-20%
Risk of hypertensive disease in pregnancy if previous preeclampsia
1 in 7
Risk of developing preeclampsia if previous preeclampsia necessitating delivery before 34 weeks
1 in 3
Risk of congenital malformations with anti epileptic drugs?
Lamotrigine: 2%
Carbamazepine : 3.4%
Sodium valproate: 10.7%
AED poly therapy: 16.8%
Background rate: 2.3%
Risk of neonatal congenital CMV infection
1st and 2nd trimester: 30-40%
3rd trimester: 40-70%
Percentage of Brenner tumors showing malignant change
5%
Ultrasound frequency for TVUS
5-7.5 MHz
Percentage of free thyroid hormones in circulation
T3: 0.3%
T4: 0.03%
Gestation at which differentiation of external genitalia happens
9-11 weeks
Percentage of non epithelial ovarian cancer
10%
Risk of cystic fibrosis in Caucasian population
1 in 25
Cord gases interpretation
Arterial or venous <7.1 is severe
BE more than 12 is severe
Arterial normal is 7.28
Venous normal is 7.35 (like adult)
BE +/- 4 is normal
Which day of the menstrual cycle does inhibin B peak?
Day 7
Risk of needing a blood transfusion following physiological third stage of labour
40 in 1000
Risk of needing a blood transfusion following active management of the third stage of labour
14 in 1000
Risk of nausea and vomiting during active management of the third stage of labour
100 in 1000
Risk of blood loss of more than 1000 mL during physiological management of the third stage of labour
29 in 1000
Dose of adrenaline for anaphylaxis
0.5 mL of 1 in 1000 IM (500 mcg)
Proportion of women in the UK who are Rh neg (white population)
Approx 16%
Temperature of the room for preterm babies
At least 26 degrees
Fetal blood volume
10-12% of body weight
At the moment of birth, blood volume is 78mL per kg (approx 280mL for 3.5kg baby)
DCC for up to 5 min increases to 126 mL/kg
Response time following IV oxytocin
Uterine response occurs almost immediately (1 min)
Uterine response time following IM oxytocin
3-5 minutes
Persists for 2-3 hours
Uterine response following ergometrine
IV - immediate and persists for 45 min (not recommended due to risk of severe hypertension)
IM - 2-5 minutes, persists for 3+ hours
Moderately useful positive predictive value
5-10
Very useful positive predictive value
> 10
Moderately useful negative predictive value
0.1 - 0.2
Very useful negative predictive value
0.1
Threshold value for positive FFN
50 ng/mL
Components of mature human breast milk
Fat 3-5%
Protein 0.8-0.9% (higher in colostrum)
Carbohydrates (lactose) 6.9-7.2%
Mineral constituents 0.2%
Size of particles in surgical smoke
0.1-5 micrometres
Spinal segment where aorta and IVC pass through diaphragm
Aorta: T12
IVC: T8
Half life of LH and FSH
LH: 20 min
FSH 3-5 hours
Percentage increase in plasma volume in the first trimester
40-50%
Percentage increase in red cell mass in the first trimester
25-30%
Percentage increase in respiratory volumes in early pregnancy
- minute volume
- residual volume, functional residual capacity and expiratory reserve volume
- vital capacity and expiratory reserve
- PEFR and FEV1
Minute volume 50%
Residual volume, functional residual capacity and expiratory reserve volume all decrease by 20%
Vital capacity and expiratory reserve are unchanged
Physiological dead space increases
PEFR and FEV1 unchanged
Percentage increase in cardiovascular parameters during first trimester:
Cardiac output
Blood volume
Heart rate
Pulmonary capillary pressure
Pulmonary vascular resistance
Cardiac output 40%
Blood volume 50%
Heart rate 10%
Pulmonary capillary pressure unchanged
Pulmonary vascular resistance falls by 35%
By which week does the nadir of BP happen?
Week 24
ECG changes in pregnancy
Deviation of electrical axis to the left by 15 degrees
ST segment depression and flattening/depression of T waves in III
Cardiac output changes in labour
First stage increase by 10-25%
Second stage increase by 40%
Immediately after delivery increase by 10-20%
Diameters of fetal skull:
Suboccipito-bregmatic
Suboccipito-frontal
Occipitofrontal
Submento-bregmatic
Submento-vertical
Mento-vertical
Suboccipito-bregmatic 9.5 cm (occipital protuberance to anterior fontanelle)
Suboccipito-frontal 10cm + (incomplete flexion)
Occipitofrontal 11.5cm (to the root of the nose = OP position)
Submento-bregmatic 9.5cm (completely extended face presentation)
Submento-vertical 11.5cm (incompletely extended face)
Mento-vertical 13.5cm (brow - cannot be delivered vaginally)
Renal physiological changes in pregnancy
GFR increased by 50% (peak between 16-24 weeks, falls in late pregnancy)
Renal plasma flow increases by 75%
Serum urea and creatinine decrease by 25%
Colloid osmotic pressure decreased by 10%
Aldosterone increased 6-8x - increases salt and water reabsorption
Total body water increases by 6-8L (ECF by 3L, 1.5L of which is plasma)
Increased protein excretion
Percentages of bound and free testosterone
Men: Free (metabolically active) 1-2%
Bound to sex hormone binding globulin 69%
Bound to albumin 30%
Women: Free 1%
80% SHBG, 19% albumin
Recurrence rate of ectopic pregnancy
18.5% (15-20%)
Percentage of aldosterone bound to plasma proteins
50%
Proportion of catecholamines produced by the adrenal medulla
85% adrenaline and 15% noradrenaline
Half life of glucagon and insulin
6 minutes
Chance of pneumonia complicating varicella in pregnancy
10-14%
Risk of progression of leiomyoma to leiomyosarcoma
0.1%
Risk of recurrence of preeclampsia
15-20%
Percentages of white blood cells
Lymphocytes
Neutrophils
Eosinophils
Lymphocytes 20-40%
Neutrophils 40-60%
Eosinophils 2-5%
Shoulder dystopias risk of brachial plexus injury
2.3-16%
Which day does the neural tube close?
Day 28
most commonly injured vessel in sacrospinous ligament suspension
Inferior gluteal artery
The male equivalent of the Skene gland is the
Prostate
The ductus arteriosus is derived from the
Sixth left pharyngeal arch
Nerve supply to pharyngeal arch derivatives
First arch - mandibular branch of the trigeminal nerve
Second arch - facial nerve
Third arch - glossopharyngeal nerve
Fourth arch - superior laryngeal branch of the vagus
Sixth arch - recurrent laryngeal branch of the vagus
Percentage of couples presenting with recurrent miscarriage who carry a chromosomal anomaly
3-5%
Percentage of first trimester miscarriages with abnormal karyotype
70%
Proportion of first trimester miscarriages that have evidence of chromosomal rearrangements
5%
HCG cut off for methotrexate
Less than 3,000 IU/litre
Success rates of single dose methotrexate treatment
85-94%
Percentage of women who experience tubal rupture during follow up
7%
Recurrent ectopic rates among women trying to become pregnant, following treatment with methotrexate
8-10%
Incidence of ectopic pregnancy in the UK
1 in 100
Gestational age when CRL is 10mm
7 weeks
Fetal heart rate activity first detectable on transvaginal scanning at how many days from the LMP?
37
What proportion of women with recurrent first trimester miscarriage have anti-phospholipid antibodies?
15%
The percentage of women in the general population who have anti-phospholipid antibodies
About 2%
What percentage of molar pregnancies are complicated by the development of choriocarcinoma?
2-3% (5% of complete moles and 0.05% partial moles)
Risk of choriocarcinoma developing after a normal full term pregnancy
1in 50,000
Risk of recurrence of molar pregnancy
1 in 55 after one affected pregnancy, 1 in 7 after two
Following ectopic pregnancy, what percentage of women treated with single dose regimen of methotrexate will require surgical intervention?
About 10%
FIGO definition of “infrequent menstruation”
Cycles lasting longer than 38 days
Percentage of pituitary tumours that secrete prolactin
80%
Percentage of precocious puberty that is idiopathic in girls (and boys)
75% (40%)
Percentage of stimulated IVF cycles that develop mild OHSS
33%
Percentage of stimulated IVF cycles that develop severe OHSS
0.3-0.5%
The sensitivity of microscopy in diagnosing endocervical infection with Neisseria gonorrhoea when compared with culture
30-50%
Efficacy of CHC
Perfect use 0.3% unwanted pregnancy
Typical use 9%
PEARL index for levonorgestrel and desogesterel POP
1.41/100 woman years levonorgestrel
0.17/100 woman years desogestrel
The risk of venous thromboembolism in a woman of reproductive age not using any contraception
4-5 per 10,000 woman years
The risk of venous thrombo-embolism in the immediate post-partum period
300-400 per 10,000 woman years
The risk of expulsion of the levonorgestrel IUS or CuIUD
1 in 20
The rate of uterine perforation associated with IUC
1.2 per 1000 insertions
Bone mineral density loss at the spine after 12 months of depo-medroxyprogesterone acetate use
0.5-3%
Half life of mirabegron
50 hours
Wound strength after 2, 3, 4 and 12 weeks
2: 3-5%
3: 20%
4: 50%
12: 80%
What happens to kidney volume in fetus on postnatal day 4?
2 fold decrease in volume
Lifetime risk of breast cancer in women in the UK
15%
Lifetime risk of breast cancer in men in the UK
Less than 0.1%
Risk of endometrial cancer in a woman with Lynch syndrome
40-60%
Lifetime risk of endometrial cancer in general population
3%
Lifetime risk of ovarian cancer in Lynch Syndrome
10-12% (predominantly clear cell or endometroid in histology)
Risk of developing endometrial cancer if endometrial hyperplasia with atypia
8% after 4 years
12.4% after 9 years
27.5% after 19 years
Lifetime risk of breast and ovarian cancer in BRCA 1 mutations
Breast: 85%
Ovarian: 63%
Lifetime risk of breast and ovarian cancer in BRCA 2 mutations
Breast: 84%
Ovarian: 27%
The most appropriate gestational age for chorionic villus sampling (CVS) and amniocentesis
CVS after 10 weeks, Amnio after 15 weeks
Success rate of VBAC
85-90%
Risk of uterine rupture with VBAC
1 in 200
Risk of stillbirth beyond 42 weeks gestation
1 in 1000
Following adequate iron therapy in women with iron deficiency anaemia, haemoglobin should be expected to increase by
20 g/L over 3-4 weeks
Hyperemesis gravidarum affects what percentage of pregnancies
0.3-3.6%
The risk of neonatal herpes following vaginal birth to a woman with primary genital herpes around the time of delivery
About 40%
The risk of neonatal herpes following vaginal birth to a woman with recurrent genital herpes around the time of delivery
About 1%
Risk of neonatal infection if maternal chicken pox 1-4 weeks before delivery (and risk of developing clinical varicella)
Up to 50% (23% develop clinical varicella)
Incubation period of measles
10-14 days
Risk of fetal varicella syndrome
Approx 1% and <28 weeks does not occur after 28 weeks and if very rare between 20-28 weeks
Approx 0.5% in first trimester
Maternal breast exposure to radiation during CT pulmonary angiography (CTPA)
10mGy
Fetal exposure to radiation during CTPA and V/Q scan
CTPA 0.1mGy
V/Q 0.5mGy
How long does it take for a pudendal block to become effective for vaginal operative delivery?
5-10 minutes
Uterine rupture most commonly occurs at which dilatation
4-5 cm
Max dose of lidocaine
4mg/kg without adrenaline
4-7mg/kg with adrenaline
When testing for anaesthesia prior to caesarean section, what is the lowest level of the block needed to ensure the woman is pain free?
T5
If a woman had received standard oxytocic management for the third stage of labour, by what amount would she have reduced her risk of requiring therapeutic oxytocic drugs?
44%
Plasma half life of oxytocin
1-6 minutes
Increase in caloric requirements after 1st trimester
200kcal
Nagele’s rule (for a 28 day cycle)
EDD = 9 months + 7 days
Lowest platelet count to allow vaginal birth or CS
50
Lowest platelet count to allow epidural
80
Daily dose of radiotherapy for cervical cancer
1.8-2.0 Gy
Length of urethra
Male 15-29cm long
Female 4cm long
Risk of developing SCC from VIN
15% (between 9-18.5%)
CMV affects what proportion of pregnancies
0.2-2.2% (1 in 50 to 1 in 500)
In the UK approximately 1 in 150 babies will be born with congenital CMV infection
Risk of female (and male) carriers of 13q21q or 14q21q Robertsonian translocations having a baby with Down syndrome
10% (male 1-3%)
The chance of malignant transformation occurring in a mature cystic terratoma
1%
The radiation exposure from one chest x-ray as equivalent to the amount of radiation exposure one experiences from natural surroundings in how many days?
10 days
When the variable under study cannot distinguish between the two groups, i.e. where there is no difference between the two distributions, the area will be equal to
0.5
MAP formula
Diastolic pressure + 1/3(pulse pressure)
Percentage of aldosterone bound to plasma proteins
50%
Onset and half life of oral labetalol
Onset: peak plasma levels 1-2 hours after administration
Half life: 6-8 hours
Percentage of pregnancies that have a platelet count below the normal range
8-10%
Estimated gestational age at a crown rump length of 10mm
7 weeks
Percentage of people with pancreatic cancer who have BRCA mutation
4-7%
Phenylalanine ratio between maternal and fetal circulation
Fetal 1.25-2.5 x maternal concentrations
Risk of gestational hypertension if previous gestational hypertension?
1 in 7
Risk of developing preeclampsia if chronic hypertension
Up to 1 in 50
Risk of developing hypertensive disease in pregnancy if any history of previous hypertension
1 in 5
Aim to keep platelets above what level in PPH
50
Aim to keep APTT and PT during PPH
Below 1.5
Autonomic sympathetic nerve supply to the uterus and pelvis
T10, T11, T12 and L1 spinal nerves (inferior hypogastric plexus/pelvic plexus)
Recurrence rate of polymorphic eruption of pregnancy (PUPP)
7%
Risk of developing SCC from lichen sclerosus
<5%
Risk of serious neonatal infection with PROM
1% (vs. 0.5% with intact membranes)
Incidence of placenta accreta (including increta and percreta) in the UK
1.7 per 10,000 deliveries
Incidence of PE in the UK
1.3/10,000 maternities
Relative risk of VTE in pregnancy compared to non pregnancy
4-6x
Absolute risk of VTE in pregnancy and the puerperium
1-2/1000 pregnancies
Infertility rate with endometriosis
40%
Risk of thrombosis in patient with factor V leiden compared with general population
80x higher
Half life of misoprostol
40 minutes
the male scrotum is typically how many degrees cooler than body temperature?
2-2.5 degrees celsius
Risk of fetal laceration with CS
2%
Risk of bladder injury and ureteric injury at CS
Bladder injury 1 in 1000
Ureteric injury 3 in 10,000
Percentage chance of being symptom free at 12 months following 3rd degree tear repair
60-80%
Incidence of OASIS in the UK
2.9% (6.1% in primip, 1.7% in multip)
Mortality rate of severe sepsis and septic shock
Severe sepsis 20-40%
Septic shock 60%
Incidence of PPH in the UK
13.8%
Duration of afterpains
2-3 days
How long does uterine involution take?
4-6 weeks
What is the approximate risk of HIV transmission during a single episode of receptive vaginal unprotected sexual intercourse with a known HIV positive person?
0.1%
Percentage chance of labour starting spontaneously within 24 hours of SROM at term?
60%
Frequency of endometrial surveillance in women with endometrial hyperplasia WITHOUT atypia
6 monthly
The average functioning adult kidney contains approximately how many nephrons?
1,000,000
Percentage of trichomonas infections that are asymptomatic
50%
Radiological volume of ovaries post menopause or ovarian failure
Approx 2 cubic cm
Frequency of monopolar diathermy
500 KHz (must be greater than 100)
Half life of ergometrine
30-120 minutes
What percentage of women develop antibodies to Human Papilloma Virus (HPV) following infection?
50-60%
Male infertility rate in CF patients
95%
Rate of molar pregnancy in the UK
1 in 600 - 1 in 2000
Number of seminiferous tubules per testis
1-3
Number of lobules per testis
250-400
CT abdomen is equivalent to how many CXR/days of background radiation
400 CXR or 2.7 years of background radiation
What percentage of unilateral ureteric injuries are diagnosed post operatively?
70%
Size of a resting follicle
0.02mm
Size of a follicle that is ready to ovulate?
20mm
What is the average haemoglobin concentration in a newborn at term?
170
With regard to plasma calcium, what proportion is carried in an ionised form?
45%
How many oocytes are available at birth and at the time of puberty
Time of birth: 1-2 million
Puberty: 400,000
What proportion of vulval cancers are squamous cell carcinoma?
90%
What is the risk of scar rupture in VBAC in spontaneous labour?
2 in 1000
Chance of being diagnosed with cervical cancer with low grade abnormality and HPV pos
0.1% (1 in 1000)
Still birth rate
1 in 200
Sudden infant death rate
1 per 10,000 live births
How long does it take the uterine cavity and placental bed to acquire a new endometrial layer?
Uterine cavity: 1 week
Placental bed: 3 weeks
At what gestation is physiological anaemia most pronounced?
32 weeks
By what percentage does oxygen consumption rise in pregnancy?
20% (50ml/min)
What is the change in total lung capacity in pregnancy?
Decreased by 200 ml
At term the maternal cardiac output is increased by 1.5 L/minute.
What percentage of this increased blood flow is distributed to the uterus?
30% (400ml/min)
Percentage of PEs that are asymptomatic
60-80%
How many hours after the LH surge does ovulation occur?
12 hours
Earliest appropriate age to perform CVS
11 weeks
Percentage of oestrogen bound and free
40% bound to SHBG
58% bound to albumin
2% free
HCG values at 1, 4, 5-6 and 7-8 weeks
1: 5-50
4: 600 - 10,000
5-6: 1,500 - 100,000
7-8: 16,000 - 200,000
Insensible losses
30 mL/kg/day
HCG at time of first missed period
Approx 100
