GTG 2018 - Care of women with obesity in Pregnancy

Question 1

women with a BMI great than ___ should be advised to take ____ of folic acid 1 month prior to pregnancy and during 1st trimester.

Answer 1

BMI >30
5mg folic acid.

Question 1

Women should be informed that weight loss between pregnancies reduces the risk of:

Answer 1

Stillbirth,
hypertensive complications,
fetal macrosomia,
and increases the success of VBAC.

Question 2

What specific risk assessments are required for anaesthetics?

Answer 2

Women with a booking BMI of 40 or greater should be referred to an obstetric anaesthetist.

Question 3

what special consideration does maternal obesity have for screening for chromosomal anomalies during pregnancies?

Answer 3

All women should be offered screening but counselled that some forms of screening are slightly less effective with a raised BMI.

Question 4

What special consideration does maternal obesity have for screening for structural anomalies during pregnancy?

Answer 4

Screening and diagnostic tests for structural anomalies should be offered however women should be counselled that all forms of screening for strucural anomalies are more limited in obese pregnant women.

Question 5

Serial SFH is recommended at each antenatal appointment from what gestation.

Answer 5

Serial measurement of SFH from 24 weeks as this improves the prediction of SGA fetuses.

Question 6

Women with a BMI >35 are more likely to have innaccurate SFH measurements and should be offered

Answer 6

Serial assessment using ultrasound.

Question 7

What are the clinical risks of previous bariatric surgery to maternal and fetal health during pregnancy?

Answer 7

A minimum waiting period of 12-18 months after bariatric surgery is recommended before attempting pregnancy to allow stabilisation of body weight and to allow the correct identification and treatment of any possible nutritional deficiences that may not be evidence during the first months.

Question 8

What level of antenatal care should women with previous bariatric surgery have?

Answer 8

They have a high risk pregnancy and should have consultant led care.

Question 9

What specific monitoring should women with previous bariatric surgery have?

Answer 9

They should have nutritional surveillance and screening for deficiencies.
They should also be referred to a dietician.

Question 10

In 2018 what percentage of the antenatal population was obese?

Answer 10

21.3%

Question 11

In 2018 what percentage of women have a BMI in the normal range?

Answer 11

47.3%

Question 12

Which BMI ranges constitute class I, II and III obesity?

Answer 12

Class 1 - 30-34.9
Class 2 - 35-39.9
Class 3 - >40

Question 13

Can anti-obesity or weight loss drugs be recommended in pregnancy?

Answer 13

No.
Currently there is a paucity of information about the effect of anti-obesity drugs on the fetus.
In a Swedish study 248 infants exposed to orlistat there was no increase in major malformation.
Topiramate is linked to oral clefts. OR 6.26. It also presents in breastmilk
Lorcaserin showed lower birthweight which persisted into adulthood in animal studies

Question 14

In women who have had pre-eclampsia what BMI rnage should they aim for to reduce their risk of recurrence.

Answer 14

18.5-24.9 Normal range.

One study demonstrated the risk of PET increases in a linear fashion with increasing BMI.

Question 15

Obese pregnant women are at greater risk of congenital structural anomalies. Data from the Consortium on Safe Labour study has identified that even in the absence of GDM…

Answer 15

obese pregnant still women remain at risk of developing congenital cardiac defects.

Question 16

How is first trimester screening affected by BMI?

Answer 16

Maternal BMI has a significant effect on the success of obtaining accurate NT measurements. There is a high chance of unsuccessful attempts at NT measurements.
One retrospective cohort study demonstrated that the proportion of pregnant women who completed first trimester screening is inversely proportional to their BMI.

Question 17

How is NIPT screening affected by BMI?

Answer 17

Non-invasive prenatal test involves detecting free fetal DNA fractions in the maternal serum for results. These have been shown to decrease with increasing maternal weight.
Results of screening for trisomies with NIPT may therefore by less effective for obese pregnant women.

Question 18

What was the effect of high maternal BMI seen with amniocentesis?

Answer 18

For women with a BMI between 30 and 40 there is no increased risk of fetal loss.
For women with a BMI greater than 40 higher loss rates were observed.

Question 19

Obese women are at increased risk of a prolonged pregnancy and induction of labour

Answer 19

aOR 1.52 for Class I obesity
aOR 1.75 for Class II obesity
aOR 2.27 for Class III obesity

approximately 60% of obese primips and 90% of obese multips acheived vaginal birth following IOL.

Question 20

Maternal obesity is associated with an incidence of

Answer 20

Induction of labour OR 1.7
Augmentation of labour aOR 1.26
Intrapartum caesarean aOR 1.5
Shoulder dystocia OR 2.9
PPH OR 1.39
increased analgesia requirement
- aOR 1.20 for requesting epidural

Question 21

NICE recommends that women with a booking BMI greater than ________ should have birth in an obstetric unit.

Answer 21

35

Question 22

Should elective induction of labour be offered to obese women.

Answer 22

Elective induction of labour at 37 or 39 weeks may reduce the risk of caesarean section and macrosomia with no increased odds of operative vaginal birth lacerations, BPI or RDS.

Question 23

What is the effect on outcomes of IOL offered for suspected fetal macrosomia?

Answer 23

IOL for suspected fetal macrosomia did not reduce the risk of BPI however it did result in lower birthweight
fewer fractures
fewer cases of shoulder dystocia

Question 24

How does obesity effect success rates of VBAC?

Answer 24

Obesity is a risk factor for unsuccessful VBAC.
One retrospect cohort study demonstrated 54% of obese women had successful VBAC vs 70.5% of those with a normal BMI.
Those who had a normal BMI at booking but subsequently had a obese BMI at birth had reduced VBAC success 56% vs 74.2%

Question 25

When discussing VBAC with women with Class 3 obesity they should also be counselled regarding increased risks of:

Answer 25

Uterine rupture in labour
Neonatal injury
Emergency CS in women with obesity is also associated with an increased risk of serious maternal morbidity due to operative and anaesthetic difficulties.

Question 26

Regarding place of birth, which risks should a women be informed of in order to make a decision.

Answer 26

Women with obesity are at greater risk of shoulder dystocia, EMCS and atonic PPH after vaginal birth.
Immediate obstetric intervention is vital in these situations
Babies born to obese women are 1.5 time more likely to be admitted to NICU.

Question 27

How does bariatric surgery effect pregnancy outcomes?

Answer 27

A meta analysis compared obese women who had undergone bariatric surgery to obese women who had not had surgery.
Those who had bariatric surgery had lower odds of :
GDM
hypertensive disorders
fetal macrosoma
however there were increased odds for SGA babies.
There is inconsistent evidence to suggest that preterm birth may be increased.