Week 3 - H - Large for gestational age babies - Macrosomia, diabetes, twins, polyhdramnios

Question 1

Some foetus are small for their gestational age (constitutionally small or intra-uterine growth restrictions) and some are large for their gestational age

What are some of the main causes of large for dates babies?

Answer 1

• Wrong dates
• Foetal macrosomia
• Polyhydramnios
• Diabetes
• Multiple pregnancy

Question 2

Wrong dates is a simple mistake that can make a pregnancy seem small or large for their gestational age Define small for gestational age? Define feotal macrosomia?

Answer 2

Small for gestational age - infant with a birthweight below the 10th centile for gestation corrected for maternal height, weight, foetal sex and birth order

Foetal macrosomia - estimated foetal weight greater than the 90th centile

Question 3

What is the normal range for birthweight of a baby? give in punds/ounces and in kg

Answer 3

5 pounds 8 oounces to 8 pounds 13 ounces (2.5 kg to 4kg)

Question 4

An abnormally large baby may have problems when giving birth What is it known as when even though the uterus is contracting normally, the baby does not exit the pelvis during childbirth due to being physically blocked? What is it known as when the head manages to get through the pelvis but the anterior shoulder of the baby cannot pass below the pubic symphysis alting the pregnancy?

Answer 4

Labour dystocia - usually caused by foetal macrosomia or when the pelvis is too small - baby cannot exit pelvis even though uterine contractions are present Shoulder dystocia - anterior shoulder of baby cannot pass under the pubic symphysis

Question 5

What is the major concern with shoulder dystocia?

Answer 5

The major concern is the stretching of the nerves within the brachial plexus - can cause Erb’s or Klumpke;s palsy This affects the sensory and motor supplies of the hand

Question 6

What spinal nerve roots are affected in erb’s and klumpke’s palsy? What is a syndrome can Klumpke’s palsy cause?

Answer 6

Erb’s palsy - affects the C5 and C6 nerve roots and is far more common than Klumpkes palsy

Klumpke’s palsy affects C8 and T1 spinal nerve roots

• Klumpke’s can cause Horner syndrome if the T1 root is affected - may affect sympathetic chain

Question 7

Polyhdramnios is excess amniotic fluid What are known causes of polyhdramnios? What is hydrops fetalis? Can cause polyhdramnios

Answer 7

• MAternal diabetes
• Monochorionic twin pregnancy
• Rhesus disease
• Fetal anomaly

Hydrops foetalis is where there is accumulation of fluid in tow or more sites in the foetus

Question 8

What diseases are known to cause hydrops foetalis? (name two)

Answer 8

Rhesus disease (rheuss isoimmunisation) and infection eg erythrovirus B19

Question 9

Clinical features of polyhdraminos include Abdominal discomfort Prelabour rupture of membranes Preterm labour Cord prolapse What is the amniotic fluid index for diagnosing polyhdraminios?

Answer 9

Amnitoic fluid index is measured by splitting the abdomen into 4 quadrans - The AFI method uses the sum of measurements obtained for the deepest vertical pocket from four quadrants of the uterus AFI greater than 25 is polyhdraminos

Question 10

Instead of measuring the amntioic fluid index, the deepest vertical pocket of the deepest quadrant can be measured instead What is the deepest vertical pocket score for polydramnios? What is the DVP and the AFI score for oligohydramnios? How are the quadrants divided?

Answer 10

• AFI - >25cm for polyhdramnios
• DVP > 8cm for polydramnios
• AFI <5cm for oligohydramnios
• DVP <2cm for oligohdramnios
• Quadrants - the linea nigra separates right from left, the umbilicus sepearates superior from inferior

Question 11

What are the causes for polydramios? What may be seen in abdominal examination of a mother with polydramnios? Now think of investigations that can be carried out to determine the causes of polydramnios?

Answer 11

Causes Maternal diabetes Hydrops detalis - rhesus disease and echovirus B19 Monochorionic twin pregnancies May see a shiny abdomen with stria (stria gravidarum) Oral glucose tolerance test - maternal diabetes Serology for presence of RhD or infection USS

Question 12

When should induction of labour be carried out in a patient with polyhydramnios?

Answer 12

INduction of labour by 40 weeks usually

Question 13

Large foetus for gestation dates Talked about, wrong dates, foetal macrosomia and polyhdramnios Next is multiple pregnancy and finally diabetes What modern advance in technology increases the incidence of multiple pregnancies? (A multiple pregnancy means that a woman has two or more babies in her uterus)

Answer 13

The use of assisted conception techniques -IVF increases the chances of multiple pregnancies

Question 14

What are the UK limits to the number of embryos used in assisted cocneption? What are the guidelines for IVF use also?

Answer 14

The UK limited the number of embryos in use to 2 The mother must be below the age of 43 and has been trying to get pregnant through regular unprotected sex for the past 2 years and been unable to get pregnant after 12 cycles of artificial insemination (Intrauterine insemination is when the sperm is artificially inseminated into the uterus)

Question 15

What factors may increase the risk of a multiple pregnancy?

Answer 15

African ethnicity Tall women Increased maternal age INcreased parity

Question 16

Multiple pregnancies are classified dependent on their zygosity and their chorionicity What are the different zygosities? Which is more common?

Answer 16

Monozygotic - this is the splitting of a single fertilised egg - accounts for 30% of twin births Dizygotic - this is the fertilisation of 2 ova by 2 sperm - accounts for 70% of twin births

Question 17

The chorionicty of twins can be 1 placenta or 2 placentas - the twins may share a placenta (monochorionic) or have one each (dichorionic) and may share or have a separate amniotic sac

Monozygotic or dizygotic twins:

• Dichorionic diamnitoic ?
• Monochorionic diamniotic?
• Monochorionic monoamniotic ?
• COnjoined twins?

Answer 17

Dizygotic twins will always be dichorionic diamniotic

Monozygotic twins may be

• Monochorionic diamniotic - most common of monozygotic twins
• Dichorionic diamniotic
• Monochorionic monoamniotic
• Conjoined twins

Question 18

What do the different types of monozygotic twin pregnancy depend upon? State the different types of monozygotic twin pregnancy again from most common to least

Answer 18

The different types of twin pregnancy depend on which days the zygote separates (splits/cleaved) to form two separate zygotes Monochorionic diamniotic - most common Dichorionic diamniotic Monochorionic monoamniotic COnjoined twins (technically monochorinic monoamniotic but there is a formed embryonic disc)

Question 19

With a dizygotic pregnancy, two ova are independently fertilised by two sperm leading to two zygotes. With a monozygotic twin pregnancy the separation of the zygote can occur at different days What are the different days of seperation for each type of monozygotic twin pregnancy?

Answer 19

Monozygocity * Dichorionic Dioamnitic - the egg splits in the first 0-3 days after fertilisation * Monochorionic diamniotic - egg splits in days 4-7 after fertilisation * Monochorionic monoamniotic - egg splits from day 8-13 after fertilisation * Conjoined twins - egg splits after day 13 of fertilisation and embryonic disc is formed

Question 20

At what stage of embryo development is the dichorionic diamniotic (DCDA), monochorionic diamniotic (MCDA) and monochorionic monoamnitoic (MCMA) formed? How many cells is the morula?

Answer 20

DCDA - at the morula stage (morula should be formed by day 3 after fertilisation and is 16 cells)

MCDA - fomed at blastocyst stage - blastocyst is formed by day4/5

MCMA - fomred by implantation (day6/7)

Question 21

What has formed and begins to differentiate by day 13 which prevents the proper splitting of what will be conjoined twins? Can dizygotic twins be conjoined?

Answer 21

The embryonic disk will have formed and therefore if the monozygote tries to split after its fomration, conjoined twins will resilt Only monozygotic twins can be conjoined

Question 22

How are multiple pregnancies diagnosed? How does it distinguish monochorionic pregnancies from dichorionic pregnancies? What is the most common type of twin pregnancy?

Answer 22

• Multiple pregnancies are diagnosed via ultrasound scanning in the first trimester -booking visit between 11-13 weeks -
• Monochorionic pregnancies show a Tsign on ultrasound
• Dichorionic show a lambda sign

DCDA is the most common type of twin pregnancy

Question 23

What are the symptoms of multiple pregnancy?

Answer 23

The uterus is large for gestational dates Exaggerated symptoms - eg hyperemesis gravidarum Multiple foetal poles

Question 24

What are the complications of a multiple pregnancy?

Answer 24

Premature birth of the foetus Growth restirction Cerebral palsy of the foetus Twin to twin transfusion

Question 25

What are some of the maternal complications due to multiple pregnancy?

Answer 25

Hyperemesis gravidarum Anaemia Pre-eclampsia Antepartum haemorrhage Pre-term birth Caesarean section

Question 26

The antepartum haemorrhage in the mother can be caused for different reasons (antepartum - occurring not long before childbirth) Two reasons are commoner - one where the placenta partially or completely separates from the uterus before birth and one where the placenta (normally located near the top of the uteru) is located near to or covering the cervix What are both of these known as?

Answer 26

Placental abruption - pthe placenta partially or completely separates from the uterus before birth

Placenta previa - the placenta (normally located near the top of the uteru) is located near to or covering the cervix

Question 27

Monochorionic means twins share the one placenta Monoamniotic twins share the one amniotic sac What does one placenta risk? What does one sac risk?

Answer 27

One placenta risks twin-to-twin transfusion syndrome (TTTS), also known as feto-fetal transfusion syndrome (FFTS) and twin oligohydramnios-polyhydramnios sequence (TOPS) - this is due to a disproportionate blood supply between twins One sac risks the entanglement of the umbilical cord in the pregnancy

Question 28

How can twin oligohydramnios-polyhydramnios sequence (TOPS) occur?

Answer 28

As a result of sharing a single placenta, the blood supplies of monochorionic twin fetuses can become connected, so that they share blood circulation. This state of transfusion causes the donor twin to have decreased blood volume, leading to a lower than normal level of amniotic fluid (becoming oligohydramnios). The blood volume of the recipient twin is increased, which can lead to excess amniotic fluid (becoming polyhydramnios).

Question 29

After the first ultrasound scan that takes place around 11-13 weeks gestation, it is normal for a second ultrasound scan to be carried out at around 20 weeks gestation If the mother is carrying twins, how often are ultrasound scans carried out after this 20 week scan? (for both monochorionic and dichoironic scans) Remember monochorionic is a greater risk

Answer 29

Clincic appointments for ultrasound is every 2 weeks if monochorionic Clinic appointments for utrasound is 4weekly for dichorionic

Question 30

What supplements should the mother take during the twin pregnancy?

Answer 30

Low dose aspirin - 75mg daily from week 12 of the regnancy Iron supplmetns

Question 31

It is important to get the timing of the pregnancy corect in twins because waiting longer can increase the risk of complication When should elective birth be offered in both di and mono chorionic uncomplicated twins pregnancies?

Answer 31

Dichorionic - offer elective birth at 37 weeks Monochorionic - offer elective birth at 36 weeks

Question 32

What is the preferred mode of delivery in: Triplets or more? Twin delivery if one is cephalic presentation? What does cephalic mean?

Answer 32

Preferred mode of delivery in triplets or more - caesaren section Cephalic presentation means head first presentation - occiput first - vertex delivery If one twin is in cephalic presentation then vaginal delivery is recommended

Question 33

What drug is given after the first twin is delivered? What is the recommended intertwin delivery time?

Answer 33

After the first twin is delivered syntocinon should be given to help with inducing labour contractions for the second delivery The intertwin delivery should ideally be <30 minutes

Question 34

Large for dates pregnancy * Wrong dates * Foetal macrosomia * Polyhdramnios * Multiple pregnancies * Diabetes Define gestational diabetes?

Answer 34

This is when there is a carbohydrate intolerance resulting in hyperglycaemia with onset or first recognition during pregnancy

Question 35

What percentage of women with gestational diabetes go on to develop diabetes mellitus?

Answer 35

Approx 50% of women develop Type 2 diabetes Mellitus

Question 36

What are the common complications of pre-existing and gestational diabetes? (getsational diabetes can cause large babies remember, think about the postpartum complication for the foetus as well)

Answer 36

Pre-eclampsia Polyhdramnios Foetal macrosomia Neonatl hypoglycaemia Shoulder dystocia

Question 37

What are the risk factors for a women developing gestational diabetes?

Answer 37

Previous gestational diabetes BMI greater than 30 Previously had a large baby - weighed more than 4.5kg (10pounds roughly) Ethnic origin - afro-carribean or middle eastern

Question 38

Pregnancies are diabetogenic - ie they cause an increase in glucose which makes you more likely to become diabetic What does the placenta release that contributes to making the mother more likely to have gestational diabetes?

Answer 38

Placenta releases CRH (corticotropin releasing hormone) which causes the release of ACTH from the anterior pituitary gland - this acts on the adrenal glands to cause production of cortisol and aldosterone (aldosterone leads to hypertenison in pregnancy) Cortisol causes an increased insulin resistance (therefore a rise in blood sugar - hyperglycaemia) which can lead to gestational diabetes in the mother

Question 39

What are the normal diagnostic criteria for diabetes mellitus?

Answer 39

Diabetes symptoms (e.g. polyuria, polydipsia and unexplained weight loss for Type 1) plus: * a random venous plasma glucose concentration ≥ 11.1 mmol/l or * a fasting plasma glucose concentration ≥ 7.0 mmol/l or * Oral glucose tolerance test - two hour plasma glucose concentration ≥ 11.1 mmol/l two hours after 75g anhydrous glucose in an oral glucose tolerance test (OGTT).

Question 40

What types of diabetes can HbA1c not be used in the diagnosis of? What is the cut off for HbA1c in the type of diabetes in can be used in?

Answer 40

An HbA1c of 48mmol/mol (6.5%) is recommended as the cut off point for diagnosing diabetes. Should not be used to diagnosed Type 1 diabetes or gestational diabetes

Question 41

Placental hormones cause the insulin resistance In the first semester screening questions for risk factors likely to cause gestational diabetes are asked If you have one or more risk factors for gestational diabetes you should be offered a screening test.

• What is the screening test and when is it carried out?
• What is the diagnostic criteria for gestational diabetes? (using either OGTT or fasting plasma glucose)

Answer 41

The screening test is an oral glucose tolerance test carried out at 24-28 weeks of pregnancy

The adoption of internationally agreed criteria for gestational diabetes using 75 g OGTT is recommended:

• * ƒ fasting venous plasma glucose ≥5.1 mmol/l, or
• * ƒ one hour value ≥10 mmol/l, or
• * ƒ two hours after OGTT ≥8.5 mmol/l.

Criteria is different in ENgland and Wales

• http://www.sign.ac.uk/assets/sign116.pdf - scottish guidline

Question 42

If the mother has had previous gestational diabetes, what can be done for screening?

Answer 42

The person can be advised to carry out BG monitoring themseleves or OGTT in the 1st trimester and another at 24-28 weeks if first is normal

Question 43

What is the cut off for diabetes? What are the diagnostic cut-offs for gestational diabetes?

Answer 43

Diabetes * Random plasma glucose - 11.1mmol/l or greeater * Fasting plasma glucose - 7.0 mmol/l or greater * OGTT - 11.1mmol/l or greater * Type 2 diabetes - also HbA1c 48mmol/l (6.5%) or greater Gestational diabetes * FAsting plasma glucose - 5.1mmol/l or greater * One hour after 75g glucose - >/=10mmol/l * OGTT (2hours after 75g glucose) - ./= 8.5mmol/l

Question 44

It is important to educate the mother how to control the gestational diabetes What should the mother be advised to do? (lifetsyle advice)

Answer 44

In women with gestational diabetes, the chances of having problems with the pregnancy can be reduced by controlling blood sugar levels. You’ll be given a blood sugar testing kit so you can monitor the effects of treatment. Blood sugar levels can be reduced by changes in diet and exercise.

Question 45

There are glycaemic targets that for a mother with gestational diabetes should aim for What is the preprandial target? What is the one hour post-prandial target?

Answer 45

Pre-prandial target - 3.5-5.9 1 hour postprandial - less than 7.8mmol/l

Question 46

When diet and exercise fail to maintain the gycaemic targets, what is the advice treatment for the gestational diabetes? What are the advantages of oral agents?

Answer 46

Oral hypoglycaemic agents or insulin Oral agents do not have the same hypoglycaemic risk as insulin and also do not require the same delivery education as required for insulin Also less weight gain

Question 47

Mode of delivery for foetal birth in gestational diabetes is usually for maternal preference or if there is any indication for C section What would the estimated foetal wight have to be for a recommended csection?

Answer 47

EFW - greater than 4.5kg

Question 48

Main risk factors for future development of type 2 diabtes in the mother include: * Obesity * Use of insulin during pregnancy * Fasting glucose levels from OGTT in pregnancy * IGT post partum (impaired glucose tolerance) * Ethnic group When is the post partum test carried out?

Answer 48

A fasting blood sugar test is carried out 6-8 weeks post natally to test for type 2 diabetes mellitus (Blood sugar of 7.0 mmol/l or greater would indicate diabtees mellitus) If signs or symptoms then can carry out an oral glucose tolerance test

Question 49

What is the normal folic acid supplemetation in women who are trying to get pregnant? What is the folic acid supplemetation in diabetic woman who are trying to get pregnant?

Answer 49

Normal folic acid supplementation - 400micrograms folic acid daily while you are trying to get pregnant and until you are 12 weeks pregnant. Diabetic woman folic acid supplementation - high dose folic acid supplemtation 5mg daily 3 months prior to conception and up to 12 weeks gestation

Question 50

What are the causes of large for gestation deates in a feotus to sum up?

Answer 50

Wrong dates Foetal macrsomia Polyhydramnios Multiple pregnancy Diabetes