Obstetrics 2 Flashcards
Can sodium valproate be used in pregnancy for epilepsy?
NO
___________ are important in maintaining the ductus arteriosus in the fetus and neonate.
Prostaglandins are important in maintaining the ductus arteriosus in the fetus and neonate.
Are NSAIDs used in preganancy?
NSAIDS are generally avoided in pregnancy unless really necessary (e.g. in rheumatoid arthritis). They are particularly avoided in the third trimester, as they can cause premature closure of the ductus arteriosus in the fetus. They can also delay labour
WHat is used for HTN in pregancy
Beta blocker- labetalol
Pregnancy
Beta-blockers can cause:
- Fetal growth restriction
- Hypoglycaemia in the neonate
- Bradycardia in the neonate
ACE Inhibitors and Angiotensin II Receptor Blockers
Can these be used in pregancy?
Medications that block the renin-angiotensin system (ACE inhibitors and ARBs) can cross the placenta and enter the fetus. In the fetus, they mainly affect the kidneys, and reduce the production of urine (and therefore amniotic fluid). The other notably effect is hypocalvaria, which is an incomplete formation of the skull bones.
no
ACE inhibitors and ARBs, when used in pregnancy, can cause:
- Oligohydramnios (reduced amniotic fluid)
- Miscarriage or fetal death
- Hypocalvaria (incomplete formation of the skull bones)
- Renal failure in the neonate
- Hypotension in the neonate
The use of _____ during pregnancy can cause withdrawal symptoms in the neonate after birth. This is called ______ ______ ________ (NAS). NAS presents between 3 – 72 hours after birth with irritability, tachypnoea (fast breathing), high temperatures and poor feeding.
The use of opiates during pregnancy can cause withdrawal symptoms in the neonate after birth. This is called neonatal abstinence syndrome (NAS). NAS presents between 3 – 72 hours after birth with irritability, tachypnoea (fast breathing), high temperatures and poor feeding.
Warfarin may be used in younger patients with ….
Warfarin may be used in younger patients with recurrent venous thrombosis, atrial fibrillation or metallic mechanical heart valves
can you use warfarin in pregancy
no
Warfarin crosses the placenta and is considered teratogenic in pregnancy, therefore it is avoided in pregnant women. Warfarin can cause:
- Fetal loss
- Congenital malformations, particularly craniofacial problems
- Bleeding during pregnancy, postpartum haemorrhage, fetal haemorrhage and intracranial bleeding
The use of sodium valproate in pregnancy causes _____ ____ ______ and _________ ___
The use of sodium valproate in pregnancy causes neural tube defects and developmental delay.
should valproate taken in girls
no
Lithium is particularly avoided in the first trimester, as this is linked with ______ ______ ________. In particular, it is associated with_____ _______, where the tricuspid valve is set lower on the right side of the heart (towards the apex), causing a bigger right atrium and a smaller right ventricle.
Lithium is particularly avoided in the first trimester, as this is linked with congenital cardiac abnormalities. In particular, it is associated with Ebstein’s anomaly, where the tricuspid valve is set lower on the right side of the heart (towards the apex), causing a bigger right atrium and a smaller right ventricle.
Can you use Selective Serotonin Reuptake Inhibitor in preganacy
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly used antidepressants in pregnancy.
. SSRIs can cross the placenta into the fetus. The risks need to be balanced against the benefits of treatment. The risks associated with untreated depression can be very significant.
Women need to be aware of the potential risks of SSRIs in pregnancy:
- First-trimester use has a link with congenital heart defects
- First-trimester use of paroxetine has a stronger link with congenital malformations
- Third-trimester use has a link with persistent pulmonary hypertension in the neonate
- Neonates can experience withdrawal symptoms, usually only mild and not requiring medical management
Isotretinoin is a retinoid medication (relating to vitamin A) that is used to treat severe acne
IT can not be used in pregnancy
WHy?
Isotretinoin is highly teratogenic, causing miscarriage and congenital defects. Women need very reliable contraception before, during and for one month after taking isotretinoin.
Name the medication that should not be used in pregnancy
Non-Steroidal Anti-Inflammatory Drugs
Beta-Blockers- except labetolol
ACE Inhibitors and Angiotensin II Receptor Blockers
Opiates
Warfarin
Sodium Valproate
Lithium
Isotretinoin (Roaccutane)
Selective Serotonin Reuptake Inhibitors?
What is Postpartum Haemorrhag
Postpartum haemorrhage (PPH) refers to bleeding after delivery of the baby and placenta. It is the most common cause of significant obstetric haemorrhage, and a potential cause of maternal death. To be classified as postpartum haemorrhage, there needs to be a loss of:
- 500ml after a vaginal delivery
- 1000ml after a caesarean section
Postpartum Haemorrhage
It can be classified as:
- Minor PPH – under 1000ml blood loss
- Major PPH – over 1000ml blood loss
Major PPH can be further sub-classified as:
- Moderate PPH – 1000 – 2000ml blood loss
- Severe PPH – over 2000ml blood loss
PPH can also be classified as
It can also be categorised as:
- Primary PPH: bleeding within 24 hours of birth
- Secondary PPH: from 24 hours to 12 weeks after birth
There are four causes of postpartum haemorrhage, remembered using the “Four Ts” mnemonic:
- T – Tone (uterine atony – the most common cause)
- T – Trauma (e.g. perineal tear)
- T – Tissue (retained placenta)
- T – Thrombin (bleeding disorder)
Risk Factors for PPH
- Previous PPH
- Multiple pregnancy
- Obesity
- Large baby
- Failure to progress in the second stage of labour
- Prolonged third stage
- Pre-eclampsia
- Placenta accreta
- Retained placenta
- Instrumental delivery
- General anaesthesia
- Episiotomy or perineal tear
Preventative Measures of PPH
Several measures can reduce the risk and consequences of postpartum haemorrhage:
- Treating anaemia during the antenatal period
- Giving birth with an empty bladder (a full bladder reduces uterine contraction)
- Active management of the third stage (with intramuscular oxytocin in the third stage)
- Intravenous tranexamic acid can be used during caesarean section (in the third stage) in higher-risk patients
Management to stabilise the patient who has PPH involves:
- Resuscitation with an ABCDE approach
- Lie the woman flat, keep her warm and communicate with her and the partner
- Insert two large-bore cannulas
- Bloods for FBC, U&E and clotting screen
- Group and cross match 4 units
- Warmed IV fluid and blood resuscitation as required
- Oxygen (regardless of saturations)
- Fresh frozen plasma is used where there are clotting abnormalities or after 4 units of blood transfusion
PPH
The treatment options for stopping the bleeding can be categorised as:
Mechanical
- Rubbing the uterus through the abdomen to stimulates a uterine contraction (referred to as “rubbing up the fundus”)
- Catheterisation (bladder distention prevents uterus contractions)
Medical
- Oxytocin (slow injection followed by continuous infusion)
- Ergometrine (intravenous or intramuscular) stimulates smooth muscle contraction (contraindicated in hypertension)
- Carboprost (intramuscular) is a prostaglandin analogue and stimulates uterine contraction (caution in asthma)
- Misoprostol (sublingual) is also a prostaglandin analogue and stimulates uterine contraction
- Tranexamic acid (intravenous) is an antifibrinolytic that reduces bleeding
Surgical
- Intrauterine balloon tamponade – inserting an inflatable balloon into the uterus to press against the bleeding
- B-Lynch suture – putting a suture around the uterus to compress it
- Uterine artery ligation – ligation of one or more of the arteries supplying the uterus to reduce the blood flow
- Hysterectomy is the “last resort” but will stop the bleeding and may save the woman’s life
What is Secondary Postpartum Haemorrhage
Secondary postpartum haemorrhage is where bleeding occurs from 24 hours to 12 weeks postpartum. This is more likely to be due to retained products of conception (RPOC) or infection (i.e. endometritis).
Secondary Postpartum Haemorrhage
Investigations involve:
Ultrasound for retained products of conception
Endocervical and high vaginal swabs for infection
Secondary Postpartum Haemorrhage
Management depends on the cause:
- Surgical evaluation of retained products of conception
- Antibiotics for infection
Labour and delivery normally occur between 37 and 42 weeks gestation.
There are three stages of labour:
What are they?
- First stage – from the onset of labour (true contractions) until 10cm cervical dilatation
- Second stage – from 10cm cervical dilatation until delivery of the baby
- Third stage – from delivery of the baby until delivery of the placenta
Explain First stage of labour and the three phases it has
The first stage of labour is from the onset of labour (true contractions) until the cervix is fully dilated to 10cm. It involves cervical dilation (opening up) and effacement (getting thinner). The “show” refers to the mucus plug in the cervix, which prevents bacteria from entering the uterus during pregnancy, falling out and creating space for the baby to pass through.
The first stage has three phases:
- Latent phase – from 0 to 3cm dilation of the cervix. This progresses at around 0.5cm per hour. There are irregular contractions.
- Active phase – from 3cm to 7cm dilation of the cervix. This progresses at around 1cm per hour, and there are regular contractions.
- Transition phase – from 7cm to 10cm dilation of the cervix. This progresses at around 1cm per hour, and there are strong and regular contractions.
What is Braxton-Hicks Contractions
Braxton-Hicks contractions are occasional irregular contractions of the uterus. They are usually felt during the second and third trimester. Women can experience temporary and irregular tightening or mild cramping in the abdomen. These are not true contractions, and they do not indicate the onset of labour.
They do not progress or become regular. Staying hydrated and relaxing can help reduce Braxton-Hicks contractions.
Diagnosing the Onset of Labour
The signs of labour are:
- Show (mucus plug from the cervix)
- Rupture of membranes
- Regular, painful contractions
- Dilating cervix on examination
NICE guidelines on intrapartum care (2017) refer to the latent first stage and established list stage.
The latent first stage is when there are both:
The established first stage of labour is when there are both:
The latent first stage is when there are both:
- Painful contractions
- Changes to the cervix, with effacement and dilation up to 4cm
The established first stage of labour is when there are both:
- Regular, painful contractions
- Dilatation of the cervix from 4cm onwards
What the definitions for these phrases
Rupture of membranes (ROM):
Spontaneous rupture of membranes (SROM):
Prelabour rupture of membranes (PROM):
Preterm prelabour rupture of membranes (P‑PROM):
Prolonged rupture of membranes (also PROM):
Rupture of membranes (ROM): The amniotic sac has ruptured.
Spontaneous rupture of membranes (SROM): The amniotic sac has ruptured spontaneously.
Prelabour rupture of membranes (PROM): The amniotic sac has ruptured before the onset of labour.
Preterm prelabour rupture of membranes (P‑PROM): The amniotic sac has ruptured before the onset of labour and before 37 weeks gestation (preterm).
Prolonged rupture of membranes (also PROM): The amniotic sac ruptures more than 18 hours before delivery.
Prematurity is defined as birth before
37 weeks gestation
From what weeks is resuscitation not considered in babies that do not show signs of life.
23 to 24 weeks,
The World Health Organisation classify prematurity as:
Under 28 weeks: extreme preterm
28 – 32 weeks: very preterm
32 – 37 weeks: moderate to late preterm
What are Prophylaxis of Preterm Labour
Vaginal Progesterone
Cervical Cerclage
What is the role of Progesterone
Progesterone can be given vaginally via gel or pessary as prophylaxis for preterm labour. Progesterone has a role in maintaining pregnancy and preventing labour by decreasing activity of the myometrium and preventing the cervix remodelling in preparation for delivery. This is offered to women with a cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation
What is Cervical Cerclage
Cervical cerclage involves putting a stitch in the cervix to add support and keep it closed. This involves a spinal or general anaesthetic. The stitch is removed when the woman goes into labour or reaches term.
Cervical cerclage is offered to women with a cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation, who have had a previous premature birth or cervical trauma (e.g. colposcopy and cone biopsy).
“Rescue” cervical cerclage may also be offered between 16 and 27 + 6 weeks when there is cervical dilatation without rupture of membranes, to prevent progression and premature delivery.
What is Preterm Prelabour Rupture of Membranes
Preterm prelabour rupture of membranes is where the amniotic sac ruptures, releasing amniotic fluid, before the onset of labour and in a preterm pregnancy (under 37 weeks gestation)
Rupture of membranes can be diagnosed by speculum examination revealing pooling of amniotic fluid in the vagina. No tests are required.
Where there is doubt about the diagnosis, tests can be performed:
- Insulin-like growth factor-binding protein-1 (IGFBP-1) is a protein present in high concentrations in amniotic fluid, which can be tested on vaginal fluid if there is doubt about rupture of membranes
- Placental alpha-microglobin-1 (PAMG-1) is a similar alternative to IGFBP-1
Management for Premature Labour
Prophylactic antibiotics should be given to prevent the development of chorioamnionitis. The NICE guidelines (2019) recommend erythromycin 250mg four times daily for ten days, or until labour is established if within ten days.
Induction of labour may be offered from 34 weeks to initiate the onset of labour.
What is Preterm Labour with Intact Membranes
Preterm labour with intact membranes involves regular painful contraction and cervical dilatation, without rupture of the amniotic sac.
Preterm Labour with Intact Membranes
Diagnosis
Clinical assessment includes a speculum examination to assess for cervical dilatation. The NICE guidelines (2017) recommend:
- Less than 30 weeks gestation, clinical assessment alone is enough to offer management of preterm labour.
- More than 30 weeks gestation, a transvaginal ultrasound can be used to assess the cervical length. When the cervical length on ultrasound is less than 15mm, management of preterm labour can be offered. A cervical length of more than 15mm indicates preterm labour is unlikely.
What is an alternative to transvaginal ultrasound
Fetal fibronectin is an alternative test to vaginal ultrasound. Fetal fibronectin is the “glue” between the chorion and the uterus, and is found in the vagina during labour. A result of less than 50 ng/ml is considered negative, and indicates that preterm labour is unlikely.
Management
There are several options for improving the outcomes in preterm labour:
- Fetal monitoring (CTG or intermittent auscultation)
- Tocolysis with nifedipine: nifedipine is a calcium channel blocker that suppresses labour
- Maternal corticosteroids: can be offered before 35 weeks gestation to reduce neonatal morbidity and mortality
- IV magnesium sulphate: can be given before 34 weeks gestation and helps protect the baby’s brain
- Delayed cord clamping or cord milking: can increase the circulating blood volume and haemoglobin in the baby at birth
What is Tocolysis
Tocolysis involves using medications to stop uterine contractions.
Nifedipine, a calcium channel blocker, is the medication of choice for tocolysis.
Atosiban is an oxytocin receptor antagonist that can be used as an alternative when nifedipine is contraindicated.
Giving the mother corticosteroids helps to develop the fetal lungs and reduce respiratory distress syndrome after delivery. They are used in women with suspected preterm labour of babies less than 36 weeks gestation.
What is an example regime
An example regime would be two doses of intramuscular betamethasone, 24 hours apart.
Giving the mother __ __________ ______ helps protect the fetal brain during premature delivery.
Giving the mother IV magnesium sulfate helps protect the fetal brain during premature delivery
Magnesium Sulfate in pregnancy reduces the risk of?
It reduces the risk and severity of cerebral palsy.
Mothers need close monitoring for magnesium toxicity at least four hourly. This involves close monitoring of observations, as well as tendon reflexes (usually patella reflex). Key signs of toxicity are:
- Reduced respiratory rate
- Reduced blood pressure
- Absent reflexes
Induction of labour (IOL) refers to
the use of medications to stimulate the onset of labour.
Induction of labour can be used where patients go over the due date. IOL is offered between 41 and 42 weeks gestation.
Induction of labour is also offered in situations where it is beneficial to start labour early, such as:
- Prelabour rupture of membranes
- Fetal growth restriction
- Pre-eclampsia
- Obstetric cholestasis
- Existing diabetes
- Intrauterine fetal death
What is Bishop Score
The Bishop score is a scoring system used to determine whether to induce labour.
Bishop Score
Five things are assessed and given a score based on different criteria (minimum score is 0 and maximum is 13):
- Fetal station (scored 0 – 3)
- Cervical position (scored 0 – 2)
- Cervical dilatation (scored 0 – 3)
- Cervical effacement (scored 0 – 3)
- Cervical consistency (scored 0 – 2)
A score of 8 or more predicts a successful induction of labour. A score below this suggests cervical ripening may be required to prepare the cervix.
What are the options for Induction of Labour
Induction of Labour
Vaginal prostaglandin E2 (dinoprostone)
Cervical ripening balloon (CRB)
Artificial rupture of membranes with an oxytocin infusion
What is used to induce labour where intrauterine fetal death has occurred.
Oral mifepristone (anti-progesterone) plus misoprostol
What is membrane sweep
Membrane sweep involves inserting a finger into the cervix to stimulate the cervix and begin the process of labour. It can be performed in antenatal clinic, and if successful, should produce the onset of labour within 48 hours. A membrane sweep is not considered a full method of inducing labour, and is more of an assistance before full induction of labour. It is used from 40 weeks gestation to attempt to initiate labour in women over their EDD
What is Vaginal prostaglandin E2 (dinoprostone)
Vaginal prostaglandin E2 (dinoprostone) involves inserting a gel, tablet (Prostin) or pessary (Propess) into the vagina. The pessary is similar to a tampon, and slowly releases local prostaglandins over 24 hours. This stimulates the cervix and uterus to cause the onset of labour. This is usually done in the hospital setting so that the woman can be monitored before being allowed home to await the full onset of labour.
What is Cervical ripening balloon (CRB)
is a silicone balloon that is inserted into the cervix and gently inflated to dilate the cervix. This is used as an alternative where vaginal prostaglandins are not preferred, usually in women with a previous caesarean section, where vaginal prostaglandins have failed or multiparous women (para ≥ 3).