Modern maternity care
1 Discuss how maternity care has changed since its inception.
The modern National Health Service (NHS) was established by an Act of Parliament in 1946. This bill instigated
free maternity care for all women. (1 mark)
Antenatal care was perceived as beneficial, acceptable and available for all. This was reinforced by the finding that
the perinatal mortality rate seemed to be inversely proportional to the number of antenatal visits. (2 marks)
The cooperation card was launched on the NHS maternity services the 1950s. This allowed a continuous record
to be held by the mother and improved the communication between all health care professionals involved in the
delivery of maternity care. (2 marks)
The advent of obstetric ultrasound brought with it a dramatic revolution in the antenatal care and screening for
fetal anomalies. This has allowed early pregnancy viability and accurate dating of pregnancies. Improved technologies with ultrasound have given rise to fetal anomaly screening. (3 marks)
During the early 1950s, there was a move toward hospital confinement from home confinement. Home deliveries
are now an infrequent event with a countrywide average of about 2 per cent. (2 marks)
Screening has formed part of antenatal care since its inception. There are discrepancies in the screening tests offered
for various diseases including Down’s syndrome. The National Screening Committee has been set up to improve
screening standards. (2 marks)
See Chapter 2, Obstetrics by Ten Teachers, 18th edition.Short answer questions 33
Maternal and perinatal mortality: the confidential enquiry
2 Write short notes on maternal mortality, perinatal mortality and Confidential Enquiry into Stillbirths and
Deaths in Infancy (CESDI).
Maternal mortality
This can be defined as the death of a woman while pregnant, or within 42 days of the termination of pregnancy,
from any cause related to, or aggravated by, the pregnancy or its management, but not from accidental or incidental causes. In the UK, this is the number of deaths from obstetric causes per 100 000 maternities. (2 marks)
This can be further subdivided into direct and indirect deaths. Direct deaths are those resulting from an obstetric complication, the most common being thromboembolism and hypertensive disorders. (2 marks)
Indirect deaths are those resulting from a previous existing disease or disease that developed during pregnancy
and which is not due to a direct obstetric cause. The most common causes of indirect death are cardiac disease
and psychiatric disorders. (2 marks)
Perinatal mortality
This is defined as the number of stillbirths and early neonatal deaths per 1000 live births and stillbirths.
(2 marks)
The most common cause of death is antenatal fetal death, of this a quarter is unexplained, a quarter is associated with intrauterine growth retardation, and the remainder are associated with placental abruption and
diabetes. (1 mark)
The next most common cause of death is immaturity. Although only 8 per cent of babies are born prematurely,
this group comprises 50 per cent of all neonatal deaths. The immediate causes of death amongst this group
include respiratory distress syndrome and neurological causes. (2 marks)
CESDI
This enquiry was set up in the early 1990s to improve the understanding of how the risk of death from 20 weeks
of pregnancy to 1 year after birth might be reduced. (2 marks)
All deaths are notified to the regional coordinator so the full clinical picture can be obtained. A specialist panel
will review only a subset of the cases. Each panel consists of experts from several disciplines, including an obstetrician, a paediatrician, a perinatal pathologist, a general practitioner and an independent chair. The panel grade
the cases from 0 to 3. Grade 0 equates to no substandard care and 3 to suboptimal care, and a change in management would be expected to alter the outcome. (3 marks)
See Chapter 3, Obstetrics by Ten Teachers, 18th edition.
Physiological changes in pregnancy
3 Outline the physiological changes that occur in response to pregnancy in the cardiovascular system, the
cervix and the respiratory system.
Cardiovascular system
Early pregnancy is characterized by a decrease in the peripheral vascular resistance. A significant increase in the
heart rate is observed as early as 5 weeks, and this contributes to an increase in cardiac output. This increase in
heart rate continues into the third trimester. The stroke volume increases in the late first trimester and further
increases the cardiac output. (4 marks)
Cervix
Under the influence of the pregnancy hormones oestradiol and progesterone, the cervix becomes swollen and
softer during pregnancy. Oestradiol stimulates the growth of the columnar epithelium of the cervical canal and34 Obstetrics
this becomes visualized as an ectopy. Increased vascularity of the cervix causes it to become a blueish colour.
Prostaglandins induce remodelling of the cervical collagen towards term, which allows softening. (4 marks)
Respiratory system
Dramatic changes occur in the respiratory system with the onset of pregnancy. The increased cardiac output
causes a substantial increase in the pulmonary blood flow. There is an increase in the tidal volume. These two
effects combine to give more efficient oxygen exchange. This increase oxygen exchange causes a decrease in
pCO2 and a slight increase in pO2. Thus oxygen availability to the tissues increases. The mechanical changes
that occur in the lung include increases in the tidal volume, and decreases in the vital capacity and functional
residual capacity. (4 marks)
See Chapter 5, Obstetrics by Ten Teachers, 18th edition.
Normal fetal development
4 Write short notes on the fetal cardiovascular system and fetal blood.
Fetal cardiovascular system
The fetal circulation is significantly different from that of the adult. The lungs do not participate in oxygen
exchange; therefore, their blood supply is significantly reduced. This reduction is achieved via the ductus arteriosus, which shunts blood away from the pulmonary artery and into the aorta. (3 marks)
All oxygenation occurs within the placenta; therefore, blood passing back from the placenta needs to pass directly
into the left side of the circulation. This is achieved in two ways. First, the ductus venous is present within the
liver to direct blood into the right atrium of the heart. Second, the foramen ovale shunts oxygenated blood from
the right atrium into the left atrium. (3 marks)
Fetal blood
The first fetal blood cells are formed on the surface of the yolk sac and haemopoiesis continues at this site until
the third month. During the fifth week of life, the extramedullary haemopoiesis begins in the liver and, finally,
bone marrow production starts at 7–8 weeks and reaches its peak by the 26th week of life. (3 marks)
Haemoglobin F (HbF) is the most common in the fetus. HbF has a higher affinity for oxygen than adult haemoglobin (HbA), therefore enhancing gaseous exchange across the placenta. The production of HbA is initiated at
around 28 weeks and, by term, it makes up 20 per cent of the blood haemoglobin. (3 marks)
See Chapter 6, Obstetrics by Ten Teachers, 18th edition.
Antenatal care
5 Write short notes on booking blood investigations, antenatal visit examination and customized antenatal
care.
Blood tests
All pregnant women should be encouraged to undergo screening for a number of health issues. The following
blood tests are normally performed. A full blood count is taken to screen for anaemia and thrombocytopenia.
The woman’s blood group and red-cell antibodies are also determined. If the woman is rhesus negative, then she
will be offered prophylactic anti-D administration at 28 and 32 weeks’ gestation. Maternal blood will be screened
for hepatitis B, human immunodeficiency virus (HIV) and syphilis. If any of these are positive, then appropriate treatment is initiated. In the case of HIV, this includes commencing antiviral drugs and offering Caesarean
section. If the patient was a carrier or had presence of a recent infection, then the fetus should be actively and
passively immunized at birth. Syphilis is treated with high-dose maternal antibiotics. (5 marks)Short answer questions 35
Antenatal visit examination
At each visit, the mother’s blood pressure is tested to screen for pre-eclampsia. The maternal abdomen is palpated
to confirm fetal presentation. The symphysis–fundal height is measured to screen fetal growth. (5 marks)
Customized antenatal care
Through the process of booking and antenatal care it may become apparent that a women and her pregnancy
have risk factors that are not met by standard services. In these cases, referral to other caregivers may be appropriate to ensure that the woman has customized antenatal care. One example of this is diabetes, where women
receive customized care within a dedicated clinic. (5 marks)
See Chapter 7, Obstetrics by Ten Teachers, 18th edition.
Antenatal imaging and fetal assessment
6 Describe the use of ultrasound in obstetrics.
Ultrasound scanning is one of the most commonly used modalities in obstetrics. It can be carried out throughout all gestations to assess the fetus and surrounding structures. (1 mark)
In the first trimester, it is used to confirm viability, for accurate dating, and the diagnosis of twin pregnancies. It
is also used for the determination of chorionicity in twin pregnancies. Uterine abnormalities and ovarian cysts
may be determined during the first trimester scan. Within the first trimester, there is opportunity for ultrasound
screening with the nuchal translucency. (4 marks)
During the second trimester, the anomaly scan is performed. This is undertaken at approximately 20 weeks. It
involves a detailed structural survey of the fetus to detect any abnormalities. Uterine artery Doppler scans may
be performed to determine if the mother has an increased risk of developing pre-eclampsia. Cervical length may
also be determined and utilized to assess the risk of preterm labour. Monochorionic twins may be assessed for
signs of twin–twin transfusion. (5 marks)
During the third trimester, ultrasound can be utilized to determine the placental site accurately. However,
the most important role of ultrasound during the third trimester is that of determining fetal well-being. This
is achieved by the measurement of fetal growth parameters, liquor volume and umbilical artery Doppler
measurements. (4 marks)
See Chapter 8, Obstetrics by Ten Teachers, 18th edition.
Prenatal diagnosis
7 Describe the techniques used for invasive prenatal diagnosis.
Amniocentesis is the most commonly used diagnostic test and can be performed from 15 weeks to term. It is carried out on pregnancies that have been identified as high risk by prior screening or history. (2 marks)
Amniocentesis is performed with a trans-abdominal needle and carries fetal loss rates of 0.5–1.5 per cent.
(2 marks)
Chorionic villus sampling (CVS) is an alterative to amniocentesis. It has the similar indication of increased risk
by prior screening. However, it has the advantage that it can be performed either transabdominally of transvaginally from 10 weeks’ gestation to term. (2 marks)
Chorionic villus sampling has a similar fetal loss rate to that of amniocentesis. One of the major disadvantages
of CVS is the potential for contamination of the sample by maternal cells or the presence of placental mosaicism;
this can lead to either a false-negative result, or make the result difficult to interpret. (2 marks)
Cordocentesis is the final method of invasive fetal testing. This involves the direct sampling of fetal blood from
the umbilical vein. The test is usually performed at or after 20 weeks’ gestation. (2 marks)
See Chapter 9, Obstetrics by Ten Teachers, 18th edition.36 Obstetrics
Second trimester miscarriage
8 Define second trimester miscarriage and outline the possible aetiologies.
Second trimester miscarriage is defined a pregnancy loss occurring between 12 and 24 weeks’ gestation.
(1 mark)
The likely aetiologies behind second trimester losses vary with gestation. At 12–15 weeks, the predominant cause
will be the same as first trimester losses: fetal chromosomal and structural anomalies. (2 marks)
A specific iatrogenic risk factor for late miscarriage is mid-trimester amniocentesis. This is usually performed at
between 16 and 18 weeks’ gestation and carries a risk of miscarriage of 1 in 200. (2 marks)
At the end of the second trimester, between 19 and 23 weeks, the commonest factors underlying miscarriage will be
those linked to premature labour. Overdistension of the uterus, either by multiple pregnancy or polyhydramnios,
leads to increased myometrial contractility and premature shortening and opening of the cervix. (4 marks)
Intrauterine bleeding irritates the uterus, leading to contractions, membrane damage and early rupture.
(1 mark)
Ascending infection from the vagina may pass through the cervix and reach the fetal membranes. This may have
the effect of stimulating prostaglandin release and trigger contraction of the uterus. (2 marks)
Cervical weakness that has occurred as a result of previous surgical injury or a congenital defect may allow the
cervix to shorten and open prematurely, the membranes then prolapse and may be damaged by stretching or
direct contact with a bacterial pathogen. (2 marks)
See Chapter 10, Obstetrics by Ten Teachers, 18th edition.
Antenatal obstetric complications
9 A 26-year-old woman presents in clinic at 30 weeks’ gestation. The community midwife has referred her
because she is ‘large for dates’. An ultrasound scan has demonstrated polyhydramnios. Discuss the possible causes of polyhydramnios in this pregnancy.
The causes of polyhydramnios can be divided into maternal, fetal and placental. The aim of any investigation of
polyhydramnios is to establish a diagnosis, so that a prognosis can be determined. (2 marks)
Initially a full maternal history should be taken. This should include past medical history, as there are various
diseases that can cause fetal polyhydramnios. The most common maternal disease associated with polyhydramnios is poorly controlled diabetes mellitus. Therefore, a random blood glucose level should be obtained and this
should be followed by an oral glucose tolerance test, if indicated. Maternal red cell antibodies should be checked
to exclude isoimmunization, as this is associated with fetal hydrops. (4 marks)
A detailed ultrasound should be arranged to check fetal growth, quantify the amniotic fluid index and examine
for fetal abnormality. (1 mark)
Fetal abnormalities that can cause polyhydramnios include the following.
• Neuromuscular conditions that have the effect of obstructing the swallowing of amniotic fluid by the fetus.
• Fetal gastrointestinal abnormalities, including oesophageal and duodenal atresia. These block the ingestions
of liquor into the fetus.
• Fetal hydrops, which should be excluded on an ultrasound scan, as this is associated with polyhydramnios
secondary to cardiac failure or anaemia.
• Twin-to-twin transfusion is a rare cause of acute polyhydramnios in the recipient sac of monochorionic twins.
It is associated with oligohydramnios in the other sac and requires urgent treatment by amniodrainage.
A detailed examination of the placenta may reveal a chorioangioma. (5 marks)
See Chapter 11, Obstetrics by Ten Teachers, 18th edition.Short answer questions 37
Twins and higher order multiple gestations
10 Outline the complications that may occur with a twin pregnancy.
Complications that occur in twins can be divided into those that occur in all twins and those that occur specifically to monochorionic twins. Monochorionic twins have specific complications owing to the fact that both
twins share the same placenta. (2 marks)
The overall perinatal mortality rate for twins is six times higher than for singletons. The main contributing factor to this high rate is preterm delivery. (2 marks)
Spontaneous preterm delivery is an ever-present risk in any twin pregnancy and approximately half of all twin
pregnancies deliver prematurely. In a dichorionic pregnancy, the chance of late miscarriage is approximately
2 per cent, and for monochorionic twins the risk is as high as 12 per cent. (2 marks)
Compared to singleton pregnancies, the risk of poor growth is higher in each individual twin alone and substantially raised in the pregnancy as a whole. In dichorionic twins, each fetus runs twice the risk of a low birth weight
and there is a 20 per cent chance that at least one twin will suffer poor growth. The chance of poor fetal growth
for monochorionic twins is almost double that for dichorionic twins. (3 marks)
Compared to singleton pregnancies, twins carry at least twice the risk of a baby with a birth defect. Each dichorionic twin pregnancy has at least twice the risk of a structural anomaly. In contrast, monochorionic twins carry
a risk that is four times higher. (2 marks)
Chromosomal abnormality risk increases with maternal age independent of the number of fetuses. Therefore, in
monozygotic twins, the risk is the same as for maternal age as both fetuses arise from the same egg. However,
dizygotic twins have twice the risk, as the fetuses come from two different eggs. (2 marks)
All monochronic twins share vascular anastomoses and it is an imbalance in the blood flow across these anastomoses that causes the specific complication of twin-twin transfusion syndrome. (1 mark)
See Chapter 12, Obstetrics by Ten Teachers, 18th edition.
Disorders of placentation
11 A 24-year-old woman presents at 36 weeks in her first pregnancy. She has a blood pressure of
140/100 mmHg and urine dipstix shows 3 proteinuria. Outline the management of this woman.
The most likely diagnosis is pre-eclampsia; however, this needs to be confirmed. A full history is required to
ascertain whether there are any risk factors for pre-eclampsia. These include a family history of pre-eclampsia
and multiple pregnancy. (2marks)
She should be admitted for both maternal and fetal assessment. Maternal assessment should include a full blood
count to determine platelet count. Urea and electrolytes should be determined to assess renal function. Liver
function tests should also be performed.A 24-hour urine collection should be initiated to confirm that the urinary protein is greater than 0.3 g/save. An urgent mid-stream urine and microscopy should be sent to exclude a
urinary tract infection. (3 marks)
A full medical examination of the woman should be undertaken, including; a neurological examination of
reflexes, which are brisk in pre-eclampsia. An abdominal palpation will demonstrate whether the fetus is clinically small for dates. (3 marks)
Cardiotocography (CTG) should be performed to assess immediate fetal well-being. If there are any abnormalities noted, then delivery should be considered. An ultrasound scan is useful to determine fetal well-being and
presentation. (2 marks)38 Obstetrics
A diagnosis of pre-eclampsia should merit delivery. A vaginal examination should be performed to assess the
cervix for favourability for induction of labour. If the cervix is unfavourable, then induction with prostaglandin
pessaries is indicated. If an artificial rupture of the membranes is possible, then this should be undertaken. The
fetus should be monitored continuously throughout labour. This woman requires close observation with regard
to blood pressure and urine output, and one-to-one midwifery care. (3 marks)
See Chapter 13, Obstetrics by Ten Teachers, 18th edition.
Preterm labour
12 A 27-year-old woman, who is 30 weeks’ gestation in her first pregnancy, is admitted from home with a history of painful contractions. Outline the management of this problem.
The likely differential diagnosis from the scenario is that of either preterm labour with or without membrane
rupture. (1 mark)
The first step is to take the relevant history. This should determine whether there are any risk factors for either
preterm labour or preterm rupture of the membranes (PROM). The common risk factors for both PROM and
preterm labour that should be enquired about are twin pregnancy, uterine abnormalities, cervical damage (cone
biopsy or repeat dilatation). It should also be determined whether there is a history of recurrent antepartum
haemorrhage or sepsis. A full social history should be taken to determine whether the women smokes or takes
drugs, and her social class, as all these factors increase the risk of preterm labour. (4 marks)
The diagnosis of preterm labour is difficult as women often present with vague cramp like pains and discomfort.
The coexistence of bleeding should always be taken seriously. An increased analgesia requirement can also help
refine the diagnosis. The most reliable diagnostic feature of PROM from the history is that of a sudden rush of
fluid per vaginum. (3 marks)
A full examination should be undertaken. Abdominal palpation may reveal the presence of uterine tenderness,
suggesting abruption or chorioamnionitis. Infection may lead to an increased pulse and temperature. A careful
speculum examination should be performed to determine if there is any pooling of liquor and a visual assessment of cervical dilation is possible. (2 marks)
Maternal well-being should be assessed with measurement of blood pressure, pulse and temperature. A full
blood count should be performed to determine if there is an increase in the white cell count indicating infection.
While the speculum examination is being undertaken, a high vaginal swab (HVS), a fibronectin and a nitrazine
test can be performed. A positive fibronectin test increases the probability of preterm delivery. Similarly a positive nitrazine test increases the probability of PROM. (3 marks)
Fetal assessment should include CTG to determine if there is a fetal tachycardia indicative of infection. An ultrasound scan can yield important information on liquor volume and cervical length can be determined if PROM
has been excluded. (2 marks)
Maternal steroids should be given to induce fetal lung maturity. Tocolysis should be considered to allow the
administration of maternal steroids. If PROM has been confirmed, then a 10-day course of erythromycin should
be commenced, as this has been shown to improve neonatal outcome. If the HVS is positive for beta-haemolytic
streptococcus, then intravenous antibiotics should be administered during labour. If labour continues, then
continuous fetal monitoring should be initiated. (3 marks)
See Chapter 14, Obstetrics by Ten Teachers, 18th edition.Short answer questions 39
Medical diseases of pregnancy
13 A 24-year-old woman with poorly controlled insulin-dependent diabetes attends a general practitioner
(GP) clinic, she is planning to start a family. Outline the advice specific to her condition that you would
give regarding pregnancy.
She should be advised that poor glucose control in pregnancy increases the risk of congenital anomalies and also
increases the risk of miscarriage. However, with good control, these risks are substantially reduced. (2 marks)
She should be advised that she will require hospital care and that this will take the form of a joint clinic with an
obstetrician, diabetic physician, diabetic nurses and dieticians. (2 marks)
The aim of treatment is to maintain the blood glucose levels as near normal as possible. Insulin requirements go
up during pregnancy and these will require careful monitoring. She should monitor her own blood glucose levels
and have blood taken for haemoglobin A1c to monitor long-term control. She is at increased risk of both diabetic
ketoacidosis and hypoglycaemia, and should be educated about the signs and symptoms of both. (3 marks)
It should be explained that an ultrasound scan at approximately 20 weeks’ gestation would examine for structural anomalies especially cardiac and neural tube defects. (2 marks)
There is also a risk that both diabetic nephropathy and retinopathy will worsen with pregnancy; however, these
complications usually improve postdelivery. There is an increased risk of pre-eclampsia, which will require regular monitoring of blood pressure and urine. (2 marks)
There is also an increased risk of polyhydramnios, which is associated with an increase in premature delivery.
Poor control is associated with macrosomia and an increased rate of shoulder dystocia. The unexplained stillbirth rate is increased after 36 weeks and careful fetal monitoring will be necessary. (4 marks)
During labour, normoglycaemia should be maintained using a sliding scale of insulin and blood glucose should
be tested hourly. Continuous fetal monitoring will be required during labour in view of the increased risk of her
pregnancy. (2 marks)
See Chapter 15, Obstetrics by Ten Teachers, 18th edition.
Perinatal infections
14 Write short notes on HIV, parvovirus and beta-haemolytic streptococcus.
HIV
This is caused by a RNA retrovirus. There is no indication that pregnancy causes the progression of the disease
in the mother. There is no evidence that pregnancy increases the risk of progression from HIV to the acquired
immunodeficiency syndrome (AIDS). (3 marks)
HIV has been shown to have specific effects on the pregnancy; there is an increased risk of miscarriage, preterm
delivery and intrauterine growth restriction. (3 marks)
Vertical transmission occurs in 25–40 per cent of pregnancies where there is no intervention. It is thought that
the majority of transmission occurs around the time of delivery and subsequent breast feeding. Three interventions have been shown to reduce the vertical transmission rate: avoiding breast feeding, elective Caesarean section, and antiviral medication during the later half of pregnancy and into the neonatal period. (4 marks)
Parvovirus
Parvovirus B19 is the cause slap cheek syndrome in children. The infection is asymptomatic in 50 per cent of
children and 25 per cent of adults. (2 marks)40 Obstetrics
In approximately 15 per cent of infections occurring during pregnancy, the fetus becomes chronically infected.
This leads to a persistent anaemia in utero, which may develop into non-immune hydrops. This may resolve spontaneously or may require a blood transfusion. (3 marks)
The diagnosis of primary parvovirus is confirmed by demonstration of virus-specific IgM in the maternal serum.
If this is demonstrated within the maternal serum, then the fetus needs close monitoring for signs of hydrops.
However, parvovirus is not a teratogenic virus. (3 marks)
Beta-haemolytic streptococcus
This is an asymptomatic bacterial commensal of the gut and genital tract. It is carried asymptomatically in
approximately 20–40 per cent of women. (2 marks)
It may cause severe neonatal infection and death. Although it can be detected on vaginal culture, screening and
treatment are not beneficial because of frequent recolonization post-treatment. (2 marks)
Therefore, the recommendation is that the organism should be sought by culture in complicated pregnancies or
where there has been a previous preterm delivery. If the organism is present or has been shown to be present in
a previous pregnancy, then intravenous antibiotics should be administered during labour. (2 marks)
The infants at most risk are premature, those with prolonged rupture of membranes and growth-restricted
fetuses. (2 marks)
See Chapter 16, Obstetrics by Ten Teachers, 18th edition.
Labour
15 Define primary dysfunctional labour, and outline its causes and possible treatments.
Primary dysfunctional labour is defined as poor progress, less than 1 cm per hour, in the active phase of labour.
(1 mark)
The progress of labour depends on three interconnected variables: the powers, the passages and the passenger.
(2 marks)
The most common cause of poor progress is ineffective uterine action, which is more common in the primiparous women. The treatment modalities that are available are rehydration, artificial rupture of the fetal membranes and intravenous oxytocin. (2 marks)
For adequate progress in labour, the tight application of the presenting part to the cervix is vital. Therefore, any
malpresentations of the passenger, such as a brow or breech presentation, may ultimately result in slow progress.
(2 marks)
Cephalopelvic disproportion (CPD) is also a cause of primary dysfunctional labour, and implies anatomical disproportion between the fetal head and the pelvis. It can be due to a large head, a small pelvis or a combination
of both. It should be suspected if labour progresses slowly despite oxytocin, the fetal head fails to engage,
vaginal examination shows severe moulding and caput, and the head is poorly applied to the cervix. Oxytocin
may overcome the relative CPD of an abnormal presentation, such as brow, but Caesarean section may the only
recourse, if the fetus in a favourable position. (3 marks)
Although abnormalities of the bony pelvis may cause delay of labour, abnormalities of the uterus and the cervix
may have a similar effect. An unsuspected lower uterine fibroid can prevent delay in descent of the fetal head and
result in Caesarean section. Cervical dystocia, owing to a scarred non-compliant cervix, can also result in a similar
outcome. (3 marks)
See Chapter 17, Obstetrics by Ten Teachers, 18th edition.Short answer questions 41
Operative interventions in obstetrics
16 Write short notes on ventouse and forceps
Ventouse
This is an instrument that utilizes suction to aid the delivery of the fetus. It can be used for both maternal and fetal
indications. The main maternal indication is exhaustion after prolonged pushing in the second stage, but is may
also be used when shorting of the second stage is an advantage, such with maternal cardiac disease. The main
fetal indication is suspected fetal compromise in the second stage. (4 marks)
The contraindications to its use are face presentation, gestation less than 34 weeks and marked bleeding from a
fetal blood sample site. The prerequisites for delivery with the ventouse are fully dilated, station below the ischial
spines, position known, good contractions, maternal bladder empty, adequate analgesia and maternal cooperation.
(6 marks)
The commonest maternal complication is genital tract trauma. The main fetal complications are cephalhaematoma
and, rarely, serious intracranial injuries. (2 marks)
Forceps
Obstetric forceps can be divided into two distinct groups: non-rotational or rotational forceps. (2 marks)
Non-rotational forceps have similar maternal and fetal indications to the ventouse. Non-rotational forceps have
both a cephalic and a pelvic curve. Although the general indications for forceps and ventouse are similar, there
are several specific indications for forceps: face presentation, bleeding from a fetal blood sample, the aftercoming head of a breech presentation, and delivery prior to 34 completed weeks. Obstetric forceps can also be utilized
to aid delivery of the fetal head at Caesarean section. (6 marks)
Kjelland’s (rotational) forceps lack the pelvic curve and this allows their rotation within the pelvis. The rotational
forceps have additional indications for malpresentations, such as an occipital posterior position or deep transverse arrest. (2 marks)
The commonest maternal complication is maternal trauma. The forceps are less likely to cause cephalhaematoma
but may cause rare, serious, intracranial injuries. (2 marks)
See Chapter 18, Obstetrics by Ten Teachers, 18th edition.
Obstetric emergencies
17 Write short notes on cord prolapse, shoulder dystocia and primary postpartum haemorrhage.
Cord prolapse
This is defined as a loop or loops of umbilical cord that fall through the cervix in front of the presenting
part. Cord prolapse is associated with prematurity and malpresentations. This occurs in approximately 1 in 500
deliveries. (2 marks)
The diagnosis is usually made on vaginal examination because of an abnormal CTG. If the cord is through the
vulva, it should be replaced to keep it warm. Urgent Caesarean section is required unless the cervix is fully dilated
and assisted delivery can be performed safely. (4 marks)
While the Caesarean section is being arranged, it is vital that the umbilical vein is reduced to allow oxygen to pass
to the fetus. This is achieved by placing the mother on all fours in a ‘head down’ position. A hand should be
placed in the vagina to push the presenting part up. (2 marks)
Outcome depends on many factors including gestation and other pregnancy complications. (2 marks)
Shoulder dystocia
This is defined as difficulty in delivery of the fetal shoulder. The incidence varies between 0.2 and 1.2 per cent of
deliveries. (2 marks)42 Obstetrics
There are several risk factors that predispose to shoulder dystocia. These are: large fetus, small mother, maternal
obesity, diabetes mellitus, prolonged first stage of labour, prolonged second stage of labour and assisted vaginal
delivery. (2 marks)
Shoulder dystocia should be managed by a sequence of manoeuvres designed to facilitate delivery without fetal
damage. The initial response to a shoulder dystocia should be a call for senior help. Excess traction should be
avoided at all times. The legs should be hyperflexed and abducted at the hips. Suprapubic pressure should be
applied to adduct the fetal shoulders. This should overcome 85 per cent of shoulder dystocia. If this fails, then
more complex manoeuvres are required. These involve internal rotation of the fetal shoulders and delivery of the
posterior arm. (4 marks)
Following delivery, the mother and her partner need to be debriefed regarding the events surrounding the delivery.
(2 marks)
Postpartum haemorrhage
This is defined as excess blood loss (500 mL) after delivery. This can be further subdivided into primary
(within the first 24 hours) and secondary (up to 6 weeks) postpartum haemorrhage. (2 marks)
The most common cause of massive blood loss is uterine atony. This accounts for 90 per cent of cases. The first
step is to stop the bleeding, which can be initially achieved by uterine massage or bimanual compression. Uterine
contraction can then be maintained by pharmacological methods; these include the use of ergometrine and highdose Syntocinon. The bladder should be emptied to aid contraction. If the uterus still fails to respond, then
prostaglandin F2-alpha can be administered systemically or directly into the myometrium. (4 marks)
However, if the bleeding continues despite adequate uterine contraction, the next most common cause is genital
tract trauma. The patient will require an examination under anaesthesia to explore the genital tract and repair
the damage sustained. (2 marks)
If bleeding still persists, then clotting should be checked urgently as disseminated vascular coagulation may be
present and needs to be corrected with blood products. (2 marks)
See Chapter 19, Obstetrics by Ten Teachers, 18th edition.
The puerperium
18 A 26-year-old woman who is 8 days postdelivery following a normal delivery is admitted with a pyrexia of
38.5°C. Discuss the possible diagnosis, investigations and treatments.
Postpartum pyrexia is a common occurrence, with an incidence of approximately 5 per cent. The aetiology can
be broadly divided into three separate categories: infection of the urogenital tract; breast engorgement/infective
mastalgia; and distant infection. (3 marks)
The most common cause of postnatal pyrexia is a urinary tract infection. The patient will present with dysuria,
frequency and lower abdominal pain. This pain will be localized over the bladder and may radiate to the loins.
A clean catch urine specimen should be collected and dipstix analysis may show protein and nitrates. The specimen should be sent for microscopy and culture. A full blood count, and urea and electrolytes should be sent as
a general investigation of all women with pyrexia. Antibiotic therapy should be initiated; however, this should be
altered depending on the results of urine culture. (5 marks)
Endometritis is another common infection that occur in the postnatal period. It presents with fever, rigors and an
associated offensive vaginal discharge. A vaginal swab should be taken and antibiotics commenced. (3 marks)
Breast engorgement/infective mastalgia will present with a history of breast pain. Examination may reveal an
enlarged erythematous breast. Anti-inflammatory drugs can be used to alleviate the pain and antibiotics, if
infection is considered. If a breast abscess is present, it will need incision and drainage. (4 marks)Short answer questions 43
Chest infections are another cause of pyrexia that needs to be excluded, especially in a patient with an underlying chest problem, such as asthma. The patient may present with a productive cough. Examination would
reveal evidence of consolidation at the lung bases. Sputum should be sent for culture. Antibiotics and supportive therapy with oxygen and physiotherapy are required. (3 marks)
Deep vein thrombosis may present as a postpartum pyrexia. The patient may complain of a painful swollen
leg and calf tenderness. Examination would reveal an enlarged calf that would be red, swollen and hot to the
touch. A duplex Doppler of the leg would confirm the diagnosis. Anticoagulant treatment should be initiated.
(3 marks)
A pulmonary embolism may also present with pyrexia and, therefore, any patient where the diagnosis is questioned should be investigated. This may necessitate a ventilation/perfusion (V/Q) scan, and treatment with anticoagulants. (2 marks)
See Chapter 20, Obstetrics by Ten Teachers, 18th edition.
Psychiatric disorders in pregnancy and the puerperium
19 Discuss the possible psychiatric sequelae of pregnancy and how they might be treated.
Disturbances in the emotional state are common in the postnatal period. Up to 80 per cent of women will
experience some form of emotional alteration. It most commonly occurs between days 3 and 10. (2 marks)
Mild postnatal depression affects 7 per cent of postnatal women. It is associated with social adversity, single status and poor support. The history is of an insidious onset of insomnia and difficultly in coping. The most effective treatment for mild depression is counselling, which in this group is as effective as antidepressant therapy.
(4 marks)
Severe postnatal depression occurs in 3–5 per cent of all women. Most cases can be detected at the 6-week postnatal check by use of the Edinburgh postnatal score. A total of 30 per cent of those women with this condition
will present within the first 3 months after delivery. They may present with a history of early morning wakening,
altered appetite and ahedonism. The management should include explanation and reassurance. Tricyclic antidepressant therapy is effective with results observed within 2 weeks of commencing treatment. The course
should be maintained for 6 months. (4 marks)
Postpartum psychosis affects 2 in 1000 women. One-third of these women will present will an acute episode of
mania, while the other two-thirds will present with depression. Acute management should be aimed at sedation
with neuropleptic drugs, which allows both containment and assessment. (3 marks)
A psychiatrist with an interest in postpartum psychiatric disorders should perform an assessment and it should
coincide with admission to the nearest mother and baby unit. The patient should be continued on an oral neuroleptic agent, such as haloperidol. However, these drugs have extrapyramidal side effects, which can be treated
with procyclidine. Lithium carbonate can be used for the mother who presents with a manic pathology. For
women with severe depression, the firstline treatment is electroconvulsive therapy. The mother should be continued on treatment for at least 6 months and advised that there is a 50 per cent recurrence rate. (3 marks)
See Chapter 21, Obstetrics by Ten Teachers, 18th edition.
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