Normal pregnancy and labour Flashcards
ANC visits
10 antenatal visits in the first pregnancy if uncomplicated
7 antenatal visits in subsequent pregnancies if uncomplicated
Women do not need to be seen by a consultant if a pregnancy is uncomplicated
All appointments - check BP, urine dipstick, assess maternal wellbeing & screen for domestic violence
Booking visit
Ideally < 10 weeks
General information eg. diet, alcohol, smoking, folic acid, vitamin D, antenatal classes
BP, urine dipstick, check BMI
Booking bloods/urine
- FBC, blood group, rhesus status, red cell alloantibodies, haemoglobinopathies
- hep B, syphilis
- HIV
- urine culture to detect asymptomatic bacteriuria
First trimester visits
Booking visit
10 - 13+6 weeks - early scan to confirm dates, exclude multiple pregnancy
11 - 13+6 weeks - Down’s syndrome screening including nuchal scan
Second trimester visits
16 weeks - information on the anomaly scan & blood results; if Hb < 11g/dl consider iron; routine care
18 - 20+6 weeks - anomaly scan
25 weeks (only if primip) - routine care (BP, urine dipstick, SFH)
Third trimester visits
28 weeks - routine care; second screen for anaemia & atypical red cell alloantibodies; first dose of anti-D prophylaxis
31 weeks (only if primip) - routine care
34 weeks - routine care; second dose of anti-D prophylaxis; info on labour & birth plan
36 weeks - routine care; check presentation (offer external cephalic version if indicated); info on breast feeding, vit K & baby blues
38 weeks - routine care
40 weeks (only if primip) - routine care; discussion about options for prolonged pregnancy
41 weeks - routine care; discuss labour plans & possibility of induction
ANC vitamins
Folic acid 400mcg should be given from before conception until 12 weeks
- certain women may require higher doses
Vitamin D daily
Iron supplementation not offered routinely
Vitamin A supplementation might be teratogenic
ANC foetal growth
SFH measured at each antenatal appt after 24 weeks
Concerns → USS appt
- multiple pregnancy
- BMI > 35
- large or multiple fibroids
Consider low dose aspirin at night from 12 weeks gestation → reduce incidence in those who are high risk of having a small for gestational age foetus
ANC alcohol
Advice is to exclude completely
High use may result in foetal alcohol syndrome
ANC smoking
Encourage smoking cessation & counsel about risks
NRT may be used if mothers’ wishes
Risks of smoking include low birthweight & preterm birth
ANC food-acquired infections
Listeriosis - avoid unpasteurised milk, ripened soft cheeses, pate or undercooked meat
Salmonella - avoid raw or partially cooked eggs and meat, especially poultry
ANC exercise
Strenuous exercise risk factor for small for gestational age babies
Encourage exercise at same level as pre-pregnancy if not vigorous/advise to start a gentle regular programme
Avoid contact or high risk sports & scuba diving
ANC travel
Women > 37 weeks with singleton pregnancy & no additional risk factors → avoid air travel
Women with uncomplicated, multiple pregnancies should avoid travel by air once > 32 weeks
Associated with increased risk of VTE
Correctly fitting compression stockings
ANC common problems
Reduced foetal movements - immediately contact maternity services if there is any concern about baby’s movements; no change to movements after 28 weeks gestation
- unsure → lie on left side and focus on foetal movements for 2 hours → 10 or more is normal
N&V - normally starts between 4th and 7th week and should settle by week 20
- if prolonged & severe → treatment for hyperemesis gravidarum
Heartburn - alleviate by sitting up after meals, reduce fat & space & eat smaller portions, gaviscon/PPI
Constipation - increased fibre & oral fluids; bran or wheat fibre supplements
Down’s syndrome antenatal testing
Combined test is now standard - nuchal translucency measurement + serum b-hCG + pregnancy-associated plasma protein A (PAPP-A)
11-13+6 weeks
Down’s syndrome - increased HCG, decreased PAPP-A, thickened nuchal translucency
Quadruple test
Women who book later in pregnancy, quadruple test should be offered between 15-20 weeks
- AFP, unconjugated oestriol, HCG, inhibin A
- AFP & oestriol are decreased
- HCG & inhibin A are increased
Non-invasive prenatal screening test (NIPT)
Woman has ‘higher chance result’ → offered second screening test or a diagnostic test (amniocentesis, chorionic villus sampling)
Analyses small DNA fragments that circulate in the blood of a pregnant woman → early detection of certain chromosomal abnormalities
Anaemia in pregnancy
First trimester Hb < 110 g/l, second/third trimester Hb < 105 g/l or a postpartum Hb less than 100 g/l
Plasma volume & RBC mass increase during pregnancy, however plasma volume increases disproportionately → haemodilution effect
Anaemia in pregnancy risk factors
Haemoglobinopathies - thalassaemia, sickle cell disease
Increasing maternal age
Low socioeconomic status
Poor diet
Anaemia during previous pregnancy
Anaemia in pregnancy clinical features
Dizziness, fatigue, dyspnoea
Asymptomatic
Pallor, koilonychia & angular cheilitis
Anaemia in pregnancy ix
FBC
Serum ferritin - not routinely measured
Haemoglobinopathy screening should be considered in patients with confirmed anaemia & unknown haemoglobinopathy status
Serum folate
Haemoglobin electrophoresis - beta thalassaemia, sickle cell disease
Anaemia in pregnancy mx
IDA - oral iron
Folate deficiency - increased folate supplementation
Beta thalassaemia - folate & blood transfusions as required
Sickle cell disease - folate & iron supplementation
Endocrine system adaptations in pregnancy
Levels of progesterone and oestrogen increase
- oestrogen is produced by the placenta
- progesterone is produced by the corpus luteum & later by the placenta
Increase in oestrogen → increase in hepatic production of thyroid-binding globulin → more TSH released → free T3 and T4 levels remain unchanged but total T3 and T4 levels rise
Increase in human placental lactogen, prolactin & cortisol = anti-insulin hormones → increase in insulin resistance
Mother switches to alternative source of energy = lipids → increased likelihood of ketoacidosis
Cardiovascular system adaptations in pregnancy
Progesterone acts to decrease systemic vascular resistance in pregnancy → decreased in diastolic BP during first & second trimesters of pregnancy
In response, cardiac output increases by about 30-50%
RAAS activation → increase in sodium levels & water retention → total blood volume increases
Respiratory system adaptations in pregnancy
Increase in metabolic rate, results in increased demand for oxygen → TV and minute ventilation rate help mother meet these oxygen demands
Hyperventilation → increased CO2 production & increased respiratory drive caused by progesterone
GI system adaptions in pregnancy
Upward displacement of stomach → increase in intra-gastric pressure → predispose mother to reflux
Increase in progesterone → smooth muscle relaxation, with decreases gut motility → more time for nutrient absorption but can lead to constipation
Relaxation of gallbladder → biliary tract stasis → predisposes mother to gallstones
Urinary system adaptions in pregnancy
Increased CO → increase in renal plasma flow which increases GFR by ~50%
Progesterone relaxes ureter & muscles of bladder → predispose to urinary stasis causing infections
Haematological changes in pregnancy
Increase in fibrinogen & clotting factors in blood & decrease in fibrinolysis
Increase risk of thromboembolic disease
LMWH choice of drug if necessary to give mother an anticoagulant drug
Physiological dilutional anaemia → plasma volume increases significantly but red cell mass does not increase by as much
Normal labour
Physiological process by which a foetus is expelled from the uterus to the outside world
Braxton Hicks contractions
Throughout third trimester, involuntary contractions of the uterine smooth muscle begin to occur
Occur irregularly and are thought to be a form of ‘practice contraction’
Cervical ripening
Softening of the cervix that occurs before labour
Occurs in response to oestrogen, relaxin and prostaglandins (synthesis increases in 3rd trimester due to increased oestrogen:progesterone)
Ripening involves:
- reduction in collagen
- increase in glycosaminoglycans
- increase in hyaluronic acid
- reduced aggregation of collagen fibres
Means cervix offers less resistance to presenting part of fetus during labour
Myometrial excitability
Relative decrease in progesterone in relation to oestrogen that occurs towards the end of pregnancy helps to facilitate an increase in the excitability of the uterine musculature
Mechanical stretching of the uterus also helps to increase contractility → foetus grows, contractility of muscle increases
Role of oxytocin in labour
Responsible for initiating uterine contractions
36 weeks, under influence of oestrogen, increase in number of oxytocin receptors present with the myometrium → uterus begins to respond to pulsatile release of oxytocin from the posterior pituitary gland
Ferguson reflex → positive feedback loop → contractions lead to more oxytocin being released leading to stronger contractions
First stage of labour
Results in the creation of the birth canal and lasts from the beginning of labour until the cervix is fully dilated (~10cm)
Contractions will occur every 2-3 minutes, foetal membranes rupture if haven’t already
Latent phase → slow cervical dilatation over several hours which lasts until the cervix has reached 4cm
Active phase → faster rate of cervical dilatation until 10cm reached; phase should normally last longer than 16 hours
Second stage of labour
Lasts from full dilatation of the cervix until the foetus has been expelled
Passive stage - lasts until the head of the foetus reaches the pelvic floor; rotation and flexion of the head are completed in this stage; few minutes
Active stage - pressure of the foetal head on the pelvic floor results in an urge to ‘bear down’ → woman pushes in conjunction with her contractions in order to expel the foetus
- 40 mins in nulliparous women, 20 minutes in multiparous women, > 1 hour = spontaneous labour becomes unlikely
Delivery
Once head reaches perineum → extends in order to come up and out of pelvis
Following delivery of head → rotated by 90 degrees to assist with shoulders
Anterior shoulder delivers first, body flexes laterally and anteriorly to help deliver the posterior shoulder
Once shoulder have been delivered → rest of body follows
Third stage of labour
Follows delivery and lasts until the placenta has been delivered
Uterine muscle fibres contract to compress the blood vessels supplying the placenta → shears away from the uterine wall
Typically lasts 15 minutes & up to 500ml blood loss
Normal mechanisms to control bleeding:
- contraction of the uterus constricts blood vessels in the myometrium
- pressure exerted on placental site once it has been delivered by uterus
- normal blood clotting mechanism
FGM
Refers to all procedures involving partial or total removal of the external female genitalia or other injury to the female genital organs for non-medical reasons
FGM classification
1 - partial/total removal of the clitoris and/or the prepuce
2 - partial/total removal of the clitoris and labia minora, with or without excision of the labia majora
3 - narrowing of the vaginal orifice with creation of covering seal by cutting & appositioning the labia minora and/or labia majora, with or without excision of the clitoris
4 - all other harmful procedures to female genitalia for non-medical purposes e.g. pricking, piercing, incising, scraping & cauterisation
Naegele’s rule
Begin on the first day of the LMP, subtract 3 months, add 7 days, and then add 1 year
Factors that affect accurate dating
Length of menstrual cycle
Date of last period may be incorrect - may think implantation bleeding is LMP
Pelvic girdle dysfunction
Pain in the front and/or back of the pelvis, which may affect other areas such as the hips or thighs
Usually caused by the joints moving unevenly, which can lead to the pelvic girdle becoming less stable & painful
Pelvic girdle dysfunction mx
Physiotherapy - exercises, avoid triggers, manual therapy
Can still have normal vaginal birth
Usually improves after birth
Failure to progress
Refers to when labour is not developing at a satisfactory rate
Delay in first stage of labour
Less than 2cm of cervical dilatation in 4 hours
Slowing of progress in a multiparous women
Delay in the second stage of labour
Active second stage lasts over:
- 2 hours in a nulliparous woman
- 1 hour in a multiparous woman
Interventions:
- changing positions
- encouragement
- analgesia
- oxytocin
- episiotomy
- instrumental delivery
- c-section
Failure to progress mx
Amniotomy (ARM) for women with intact membranes
Oxytocin infusion - first line to stimulate uterine contractions during labour
Instrumental delivery
C-section
Retained products of conception
Pregnancy-related tissue remain in the uterus after delivery
Can also occur after miscarriage or termination of pregnancy
Retained products of conception clinical features
Vaginal bleeding that gets heavier/does not improve with time
Abnormal vaginal discharge
Lower abdominal or pelvic pain
Fever (if infection occurs)
Diagnosis made by USS
Retained products of conception mx
Surgical removal - evacuation of retained products of conception
- cervix widened, retained products are manually removed through the cervix using vacuum aspiration & curettage
- complications - endometritis & Asherman’s syndrome
Asherman’s syndrome
Adhesions form within the uterus
Endometrial curettage can damage the basal layer of the endometrium
Damaged tissue may heal abnormally, creating scar tissue connecting areas of the uterus that are generally not connected → can lead to infertility
Cardiotocography
Used to measure the fetal heart rate and the contractions of the uterus
Can help guide decision making and delivery
Cardiotocography procedure
Two transducers are placed on the abdomen to get the CTG readout:
- one above the fetal heart → uses Doppler US
- one near the fundus of the uterus to monitor the uterine contractions → assess tension in the uterine wall
Indications for continuous CTG
Sepsis
Maternal tachycardia (> 120)
Significant meconium
Pre-eclampsia
Fresh antepartum haemorrhage
Delay in labour
Use of oxytocin
Disproportionate maternal pain
CTG decelerations
Concerning finding
Fetal HR drops in response to hypoxia
- early decelerations - gradual dips and recoveries in HR that correspond with uterine contractions; normal → caused by uterus compressing the head of the fetus, stimulating the vagus nerve, slowing the HR
- late decelerations - gradual falls in HR that starts after the uterine contraction has already begun → caused by hypoxia
- variable decelerations - abrupt decelerations that may be unrelated to uterine contractions; intermittent compression of the umbilical cord
- prolonged decelerations - last between 2 and 10 mins with a drop of more than 15bpm, indicates compression of the umbilical cord, causing fetal hypoxia
CTG mx
Escalating to a senior midwife and obstetrician
Further assessment for possible causes - uterine hyperstimulation, maternal hypotension & cord prolapse
Conservative interventions - repositioning the mother or giving IV fluids for hypotension
Fetal scalp stimulation - acceleration in response reassuring sign
Fetal scalp blood sampling - test for fetal acidosis
Delivery of baby - instrumental or emergency CS
DR C BRaVADO
Assess features of a CTG in a structured way
DR - define risk
C - contractions
BRa - baseline rate
V - variability
A - accelerations
D - decelerations
O - overall impression
Perineal tears
Occurs where the external vaginal opening is too narrow to accommodate the baby
Perineal tears classification
First degree - injury limited to the frenulum of the labia minora and superficial skin
Second degree - including the perineal muscles, but not affecting the anal sphincter
Third degree - including the anal sphincter, but not affecting the rectal mucosa
Fourth degree - including rectal mucosa
Perineal tears mx
Sutures
Broad-spectrum abx to reduce the risk of infection
Laxatives to reduce the risk of constipation
Physiotherapy
Follow-up
Elective CS in subsequent pregnancies
Perineal tears complications
Short-term: pain, infection, bleeding, wound dehiscence or wound breakdown
Long-term: urinary incontinence, anal incontinence & altered bowel habit, fistula, sexual dysfunction & painful sex, mental health consequences
Episiotomy
Obstetrician or midwife cuts the perineum before the baby is delivered
Done in anticipation of needing additional room for delivery of the baby
Perineal massage
Method for reducing the risk of perineal tears
Involves massaging the skin and tissues between the vagina and anus
Done in a structured way from 34 weeks onwards to stretch and prepare the tissues for delivery
Breastfeeding
Recommended for the first 6 months of life, with introduction of solid food around this time & continued breastfeeding up to 2 years of age or longer
Breastfeeding maternal benefits
Lowers risk of:
- breast cancer
- ovarian cancer
- osteoporosis
- CVD
- obesity
Breastfeeding foetal benefits
Reduces risk of:
- infections
- D&V
- SIDS
- obesity
- CVD in adulthood
Gas and air (entonox)
Used during contractions for short term pain relief
Woman takes deep breaths using a mouthpiece at the start of a contraction, the stops using it as the contraction eases
Can cause lightheadedness, nausea or sleepiness
IM pethidine or diamorphine
Opioid medications usually given by IM
May help with anxiety and distress
May cause drowsiness or nausea in the mother & can cause respiratory depression in the neonate if given too close to birth
Patient controlled analgesia
Patient controlled IV remifentanil
Requires careful monitoring
Access to naloxone for respiratory depression & atropine for bradycardia
Epidural
Inserting a small tube into the epidural space in the lower back
Local anaesthetic medications are infused through the catheter into the epidural space → surrounding tissues & spinal cord
Offers good pain relief during labour
Adverse effects:
- headache
- hypotension
- motor weakness in the legs
- nerve damage
- prolonged second stage
- increase probability of instrumental delivery
Urgent anaesthetic r/w if motor weakness → catheter may be in the subarachnoid space
PPROM & PROM
PROM - rupture of fetal membranes at least one hour prior to the onset of labour, at > 37 weeks gestation
P-PROM - rupture of fetal membranes occurring <37 weeks gestation
PPROM & PROM aetiology & pathophysiology
Combination of factors can lead to the early weakening & rupture of fetal membranes:
- early activation of normal physiological processes
- infection
- genetic predisposition
PPROM & PROM risk factors
Smoking (< 28 weeks gestation)
Previous PROM/pre-term delivery
Vaginal bleeding during pregnancy
Lower genital tract infection
Invasive procedures eg. amniocentesis
Polyhydramnios
Multiple pregnancy
Cervical insufficiency
PPROM & PROM clinical features
Hx of ‘broken waters’
Gradual leakage of watery fluid from vagina
Damp underwear/pad
Change in the colour/consistency of vaginal discharge
O/E - speculum: pooling of fluid in the posterior vaginal fornix; lack of normal vaginal discharge
PPROM & PROM ix
Actim-PROM - swab test looking for IGFBP-1 in vaginal samples (100-1000x conc in amniotic fluid)
Amnisure - looks for placental alpha microglobulin (found in large concentrations in amniotic fluid)
USS - not routine
High vaginal swab - GBS
PPROM & PROM > 36 weeks mx
Monitor for signs of clinical chorioamnionitis
Clindamycin/penicillin during labour if GBS
Watch & wait for 24 hours/consider IOL
IOL & delivery recommended if > 24 hours
PPROM & PROM 34 - 36 weeks mx
Monitor for signs of clinical chorioamnionitis & advise patient to avoid sexual intercourse
Prophylactic erythromycin for 10 days
Clindamycin/penicillin during labour if GBS isolated
Corticosteroids if between 34 and 34+6 weeks gestation
IOL & delivery recommended
PPROM & PROM 24 - 33 weeks mx
Monitor for signs of clinical chorioamnionitis
Advise patient to avoid sexual intercourse
Prophylactic erythromycin for 10 days
Corticosteroids
Aim expectant mx until 34 weeks
PPROM & PROM complications
Chorioamnionitis
Oligohydramnios
Neonatal death - prematurity, sepsis & pulmonary hypoplasia
Placental abruption
Umbilical cord prolapse
