Obstetrics Flashcards
What is Pre-eclampsia
Pre-eclampsia refers to new high blood pressure (hypertension) in pregnancy with end-organ dysfunction, notably with proteinuria (protein in the urine). It occurs after 20 weeks gestation, when the spiral arteries of the placenta form abnormally, leading to a high vascular resistance in these vessels.
Pre-eclampsia features a triad of:
- Hypertension
- Proteinuria
- Oedema
Pre-eclampsia is a significant cause of maternal and fetal morbidity and mortality. Without treatment, it can lead to
maternal organ damage, fetal growth restriction, seizures, early labour and in a small proportion, death.
What is Eclampsia
Eclampsia is when seizures occur as a result of pre-eclampsia.
Patho of Pre-eclampsia
When the blastocyst implants on the endometrium, the outermost layer, called the syncytiotrophoblast, grows into the endometrium. It forms finger-like projections called chorionic villi. The chorionic villi contain fetal blood vessels.
Trophoblast invasion of the endometrium sends signals to the spiral arteries in that area of the endometrium, reducing their vascular resistance and making them more fragile. The blood flow to these arteries increases, and eventually they break down, leaving pools of blood called lacunae (lakes). Maternal blood flows from the uterine arteries, into these lacunae, and back out through the uterine veins. Lacunae form at around 20 weeks gestation.
When the process of forming lacunae is inadequate, the woman can develop pre-eclampsia. Pre-eclampsia is caused by high vascular resistance in the spiral arteries and poor perfusion of the placenta. This causes oxidative stress in the placenta, and the release of inflammatory chemicals into the systemic circulation, leading to systemic inflammation and impaired endothelial function in the blood vessels.
Risk Factors for Pre-Eclampsia
High-risk factors are:
- Pre-existing hypertension
- Previous hypertension in pregnancy
- Existing autoimmune conditions (e.g. systemic lupus erythematosus)
- Diabetes
- Chronic kidney disease
Moderate-risk factors are:
- Older than 40
- BMI > 35
- More than 10 years since previous pregnancy
- Multiple pregnancy
- First pregnancy
- Family history of pre-eclampsia
Women are offered _____ from 12 weeks gestation until birth if they have one high-risk factor or more than one moderate-risk factors for pre-eclampsia
Women are offered aspirin from 12 weeks gestation until birth if they have one high-risk factor or more than one moderate-risk factors.
Pre-eclampsia has symptoms of the complications:
- Headache
- Visual disturbance or blurriness
- Nausea and vomiting
- Upper abdominal or epigastric pain (this is due to liver swelling)
- Oedema
- Reduced urine output
- Brisk reflexes
Diagnosis of Pre-eclampsia
The NICE guidelines (2019) advise a diagnosis can be made with a:
- Systolic blood pressure above 140 mmHg
- Diastolic blood pressure above 90 mmHg
PLUS any of:
- Proteinuria (1+ or more on urine dipstick)
- Organ dysfunction (e.g. raised creatinine, elevated liver enzymes, seizures, thrombocytopenia or haemolytic anaemia)
- Placental dysfunction (e.g. fetal growth restriction or abnormal Doppler studies)
Proteinuria in pregnancy can be quantified using:
- Urine protein:creatinine ratio (above 30mg/mmol is significant)
- Urine albumin:creatinine ratio (above 8mg/mmol is significant)
NICE recommends using placental growth factor PlGF between __ and __ weeks gestation to rule-out pre-eclampsia.
NICE recommends using PlGF between 20 and 35 weeks gestation to rule-out pre-eclampsia
All pregnant women are routinely monitored at every antenatal appointment for evidence of pre-eclampsia, with:
Blood pressure
Symptoms
Urine dipstick for proteinuria
When gestational hypertension (without proteinuria) is identified, the general management involves:
- Treating to aim for a blood pressure below 135/85 mmHg
- Admission for women with a blood pressure above 160/110 mmHg
- Urine dipstick testing at least weekly
- Monitoring of blood tests weekly (full blood count, liver enzymes and renal profile)
- Monitoring fetal growth by serial growth scans
- PlGF testing on one occasion
When pre-eclampsia is diagnosed, the general management is similar to gestational HTN to gestational hypertension, except:
- Scoring systems are used to determine whether to admit the woman (fullPIERS or PREP‑S)
- Blood pressure is monitored closely (at least every 48 hours)
- Urine dipstick testing is not routinely necessary (the diagnosis is already made)
- Ultrasound monitoring of the fetus, amniotic fluid and dopplers is performed two weekly
Medical management of pre-eclampsia is with:
- Labetolol is first-line as an antihypertensive
- Nifedipine (modified-release) is commonly used second-line
- Methyldopa is used third-line (needs to be stopped within two days of birth)
- Intravenous hydralazine may be used as an antihypertensive in critical care in severe pre-eclampsia or eclampsia
- IV magnesium sulphate is given during labour and in the 24 hours afterwards to prevent seizures
- Fluid restriction is used during labour in severe pre-eclampsia or eclampsia, to avoid fluid overload
What can be given o women having a premature birth to help mature the fetal lungs.
Corticosteroids
What happens if pre-eclampsia can not be controlled
Planned early birth
What is used to managed seizures in Eclampsia
. IV magnesium sulphate is used to manage seizures associated with pre-eclampsia.
complication of pre-eclampsia and eclampsia
HELLP
Haemolysis
Elevated Liver enzymes
Low Platelets
What is Gestational Diabetes
Gestational diabetes refers to diabetes triggered by pregnancy. It is caused by reduced insulin sensitivity during pregnancy, and resolves after birth.
What are common complications from gestational diabetes
The most significant immediate complication of gestational diabetes is a large for dates fetus and macrosomia.
This has implications for birth, mainly posing a risk of shoulder dystocia
. Longer-term, women are at higher risk of developing type 2 diabetes after pregnancy.
WHat should be the investigation for anyone with risk factors for gestational diabetes?
oral glucose tolerance test at 24 – 28 weeks gestation. Women with previous gestational diabetes also have an OGTT soon after the booking clinic.
RF for gestational Diabetes
The NICE guidelines (2015) list the risk factors that warrant testing for gestational diabetes:
- Previous gestational diabetes
- Previous macrosomic baby (≥ 4.5kg)
- BMI > 30
- Ethnic origin (black Caribbean, Middle Eastern and South Asian)
- Family history of diabetes (first-degree relative)
OGTT should be given to a pregant lady if:
Large for dates fetus
Polyhydramnios (increased amniotic fluid)
Glucose on urine dipstick
An OGTT should be performed in the morning after a fast (they can drink plain water). The patient drinks a ____glucose drink at the start of the test. The blood sugar level is measured before the sugar drink (fasting) and then at 2 hours.
An OGTT should be performed in the morning after a fast (they can drink plain water). The patient drinks a 75g glucose drink at the start of the test. The blood sugar level is measured before the sugar drink (fasting) and then at 2 hours.
OGTT normal results for pregnant ladies
Normal results are:
- Fasting: < 5.6 mmol/l
- At 2 hours: < 7.8 mmol/l
Results higher than these values are used to diagnose gestational diabetes.
TOM TIP: It is really easy to remember the cutoff for gestational diabetes as simply 5 – 6 – 7 – 8.
Management for gestational diabetes
The initial management suggested by the NICE guidelines (2015) is:
- Fasting glucose less than 7 mmol/l: trial of diet and exercise for 1-2 weeks, followed by metformin, then insulin
- Fasting glucose above 7 mmol/l: start insulin ± metformin
- Fasting glucose above 6 mmol/l plus macrosomia (or other complications): start insulin ± metformin
Gestational Diabetes
__________ (a sulfonylurea) is suggested as an option for women who decline insulin or cannot tolerate metformin.
Glibenclamide (a sulfonylurea) is suggested as an option for women who decline insulin or cannot tolerate metformin.
Gestationa Diabetes
Women need to monitor their blood sugar levels several times a day. The NICE (2015) target levels are:
- Fasting: 5.3 mmol/l
- 1 hour post-meal: 7.8 mmol/l
- 2 hours post-meal: 6.4 mmol/l
- Avoiding levels of 4 mmol/l or below
Before becoming pregnant, women with existing diabetes should aim for good glucose control. They should take__mg _____ ___ from preconception until 12 weeks gestation.
Before becoming pregnant, women with existing diabetes should aim for good glucose control. They should take 5mg folic acid from preconception until 12 weeks gestation.
_________ _______ should be performed shortly after booking and at 28 weeks gestation. This involves referral to an ___________ to check for _______ ________. Diabetes carries a risk of rapid progression of retinopathy, and interventions may be required.
Retinopathy screening should be performed shortly after booking and at 28 weeks gestation. This involves referral to an ophthalmologist to check for diabetic retinopathy. Diabetes carries a risk of rapid progression of retinopathy, and interventions may be required.
A sliding-scale insulin regime is considered during labour for women with type 1 diabetes. A_____ and ____ ______ is titrated to blood sugar levels, according to the local protocol. This is also considered for women with poorly controlled blood sugars with gestational or type 2 diabetes.
A sliding-scale insulin regime is considered during labour for women with type 1 diabetes. A dextrose and insulin infusion is titrated to blood sugar levels, according to the local protocol. This is also considered for women with poorly controlled blood sugars with gestational or type 2 diabetes.
Babies of mothers with diabetes are at risk of:
- Neonatal hypoglycaemia
- Polycythaemia (raised haemoglobin)
- Jaundice (raised bilirubin)
- Congenital heart disease
- Cardiomyopathy
Babies need close monitoring for ______ _______, with regular blood glucose checks and frequent feeds. The aim is to maintain their blood sugar above 2 mmol/l, and if it falls below this, they may need __ _______ of nasogastric feeding.
Babies need close monitoring for neonatal hypoglycaemia, with regular blood glucose checks and frequent feeds. The aim is to maintain their blood sugar above 2 mmol/l, and if it falls below this, they may need IV dextrose of nasogastric feeding.
If you remember two complications of gestational diabetes, remember ________ and ________ __________
If you remember two complications of gestational diabetes, remember macrosomia and neonatal hypoglycaemia.
What is placenta praevia
Placenta praevia is where the placenta is attached in the lower portion of the uterus, lower than the presenting part of the fetus. Praevia directly translates from Latin as “going before”.
The RCOG guidelines (2018) recommend the following definitions:
- Low-lying placenta is used when the placenta is within 20mm of the internal cervical os
- Placenta praevia is used only when the placenta is over the internal cervical os
What are three causes of antepartum haemorrhage?
signs?
placenta praevia, placental abruption and vasa praevia. These are serious causes with high morbidity and mortality.
Causes of spotting or minor bleeding in pregnancy include cervical ectropion, infection and vaginal abrasions from intercourse or procedures
Placenta praevia is associated with increased morbidity and mortality for the mother and fetus. The risks include:
- Antepartum haemorrhage
- Emergency caesarean section
- Emergency hysterectomy
- Maternal anaemia and transfusions
- Preterm birth and low birth weight
- Stillbirth
The RCOG guidelines (2018) recommend against using this grading system, as it is considered outdated. The two descriptions used are l____ ____ _______ a and _____ _______
The RCOG guidelines (2018) recommend against using this grading system, as it is considered outdated. The two descriptions used are low-lying placenta and placenta praevia.
The risk factors for placenta praevia are:
- Previous caesarean sections
- Previous placenta praevia
- Older maternal age
- Maternal smoking
- Structural uterine abnormalities (e.g. fibroids)
- Assisted reproduction (e.g. IVF)
Presentation and Diagnosis of placenta praevia
The 20-week anomaly scan is used to assess the position of the placenta and diagnose placenta praevia.
Many women with placenta praevia are asymptomatic. It may present with painless vaginal bleeding in pregnancy (antepartum haemorrhage). Bleeding usually occurs later in pregnancy (around or after 36 weeks).
For women with a low-lying placenta or placenta praevia diagnosed early in pregnancy (e.g. at the 20-week anomaly scan), the RCOG guideline (2018) recommends a repeat __________ ______ ______ at:
- 32 weeks gestation
- 36 weeks gestation (if present on the 32-week scan, to guide decisions about delivery)
For women with a low-lying placenta or placenta praevia diagnosed early in pregnancy (e.g. at the 20-week anomaly scan), the RCOG guideline (2018) recommends a repeat transvaginal ultrasound scan at:
- 32 weeks gestation
- 36 weeks gestation (if present on the 32-week scan, to guide decisions about delivery)
Management for Placenta Praevia
Corticosteroids are given between 34 and 35 + 6 weeks gestation to mature the fetal lungs, given the risk of preterm delivery.
Planned delivery is considered between 36 and 37 weeks gestation. It is planned early to reduce the risk of spontaneous labour and bleeding. Planned cesarean section is required with placenta praevia and low-lying placenta (<20mm from the internal os).
Emergency caesarean section may be required with premature labour or antenatal bleeding.
The main complication of placenta praevia is haemorrhage before, during and after delivery. When this occurs, urgent management is required and may involve:
- Emergency caesarean section
- Blood transfusions
- Intrauterine balloon tamponade
- Uterine artery occlusion
- Emergency hysterectomy
What is Placental Abruption
Placental abruption refers to when the placenta separates from the wall of the uterus during pregnancy.
The site of attachment can bleed extensively after the placenta separates.
Placental abruption is a significant cause of antepartum haemorrhage.
RF for Placental Abruption
The risk factors for placental abruption are:
- Previous placental abruption
- Pre-eclampsia
- Bleeding early in pregnancy
- Trauma (consider domestic violence)
- Multiple pregnancy
- Fetal growth restriction
- Multigravida
- Increased maternal age
- Smoking
- Cocaine or amphetamine use
The typical presentation of placental abruption is with:
- Sudden onset severe abdominal pain that is continuous
- Vaginal bleeding (antepartum haemorrhage)
- Shock (hypotension and tachycardia)
- Abnormalities on the CTG indicating fetal distress
- Characteristic “woody” abdomen on palpation, suggesting a large haemorrhage
The RCOG guideline (2011) defines the severity of antepartum haemorrhage as:
- Spotting: spots of blood noticed on underwear
- Minor haemorrhage: less than 50ml blood loss
- Major haemorrhage: 50 – 1000ml blood loss
- Massive haemorrhage: more than 1000 ml blood loss, or signs of shock
What is Concealed Abruption
Concealed abruption is where the cervical os remains closed, and any bleeding that occurs remains within the uterine cavity. The severity of bleeding can be significantly underestimated with concealed haemorrhage.
Concealed abruption is opposed to revealed abruption, where the blood loss is observed via the vagina.
Placental abruption is an obstetric emergency. The urgency depends on the amount of placental separation, extent of bleeding, haemodynamic stability of the mother and condition of the fetus. It is important to consider concealed haemorrhage, where the vaginal bleeding may be disproportionate to the uterine bleeding.
The initial steps with major or massive haemorrhage are:
- Urgent involvement of a senior obstetrician, midwife and anaesthetist
- 2 x grey cannula
- Bloods include FBC, UE, LFT and coagulation studies
- Crossmatch 4 units of blood
- Fluid and blood resuscitation as required
- CTG monitoring of the fetus
- Close monitoring of the mother
_________ can be useful in excluding placenta praevia as a cause for antepartum haemorrhage, but is not very good at diagnosing or assessing abruption.
Ultrasound can be useful in excluding placenta praevia as a cause for antepartum haemorrhage, but is not very good at diagnosing or assessing abruption.
There is an increased risk of _________ __________ after delivery in women with placental abruption. Active management of the third stage is recommended.
There is an increased risk of postpartum haemorrhage after delivery in women with placental abruption. Active management of the third stage is recommended.
Placental Abruption
Rhesus-D negative women require_____ ________ when bleeding occurs. A ________ ____ is used to quantify how much fetal blood is mixed with the maternal blood, to determine the dose of _____ that is required.
Rhesus-D negative women require anti-D prophylaxis when bleeding occurs. A Kleihauer test is used to quantify how much fetal blood is mixed with the maternal blood, to determine the dose of anti-D that is required.
What is Placenta Accreta
Placenta accreta refers to when the placenta implants deeper, through and past the endometrium, making it difficult to separate the placenta after delivery of the baby. It is referred to as placenta accreta spectrum, as there is a spectrum of severity in how deep and broad the abnormal implantation extends.
With placenta accreta, the placenta embeds past the endometrium, into the myometrium and beyond. This may happen due to a defect in the endometrium. Imperfections may occur due to previous uterine surgery, such as a caesarean section or curettage procedure. The deep implantation makes it very difficult for the placenta to separate during delivery, leading to extensive bleeding (postpartum haemorrhage).
WHat are the three layers to the uterine wall
- Endometrium, the inner layer that contains connective tissue (stroma), epithelial cells and blood vessels
- Myometrium, the middle layer that contains smooth muscle
- Perimetrium, the outer layer, which is a serous membrane similar to the peritoneum (also known as serosa)
Usually the placenta attaches to the________. This allows the placenta to separate cleanly during the ____ ____ __ _____, after delivery of the baby.
Usually the placenta attaches to the endometrium. This allows the placenta to separate cleanly during the third stage of labour, after delivery of the baby.
