1. a
Preconception Care in Obese Women
Lisa Webber MA BMBCh PhD MRCOG
Consultant Gynaecologist
Specialist in Reproductive Medicine

3. Principles of preconception care
To address:
• undiagnosed, untreated
or poorly controlled
medical conditions
• immunization history
• nutritional issues
• family history & genetic
risk
• substance use/high risk
behaviours
• occupational/environme
ntal exposures
• social issues
• mental health issues

4. Principles of preconception care
To address:
• undiagnosed, untreated
or poorly controlled
medical conditions
• immunization history
• nutritional issues
• family history & genetic
risk
• substance use/high risk
behaviours
• occupational/environme
ntal exposures
• social issues
• mental health issues
for obese women
✓
✓
✓ ✓
✓

6. Preconception care for obese women
• Weight reduction
– identification & treatment of eating disorders
– consider bariatric surgery if BMI >35
• Information about risks of obesity in pregnancy
& childbirth
• Nutritional supplements?
• Diabetes screening?

7. (Average height woman 1.63m tall)
starting
BMI
target
BMI
target
weight
loss (%)
target
weight
loss (kg)
35 30 14.7% 13 kg
40 35 12.5% 13 kg
40 30 25.4% 27 kg
Weight reduction

8. Optimisation of weight - impact of time
Marital fertility rates [Drawn from Menken et al. (1986) Science]

9. Reproductive effects of obesity

10. Reproductive effects of obesity
Impact of obesity on
–fertility
–the pregnant mother
–the fetus
–the child

11. Impact of obesity on fertility
• Spontaneous conception rate probably
reduced in ovulatory women

12. Impact of obesity on fertility
conception
70
50
30
10
cumulativepregnancyrate
after12cyclesDI(%)
<20 20.1-25 25.1-30 >30
BMI kg/m2
Zaadstra et al 1993

13. Impact of obesity on fertility
conception
70
50
30
10
<0.7 0.7-0.75 0.76-0.8 0.81-0.85 >0.85
waist:hip ratio
Zaadstra et al 1993
cumulativepregnancyrate
after12cyclesDI(%)

14. Impact of obesity on fertility
• Spontaneous conception rate probably
reduced in ovulatory women
• Ovulation rate reduced in women with PCOS

15. Women with PCOS vs weight-matched controls
• insulin resistant (Robinson et al 1993)
–downstream to insulin receptor (Dunaif et al 1995)
• hyperinsulinaemic
–increased secretion from β cells (Holte et al 1994)
contributes to obesity
Impact of obesity on fertility
ovulation

16. Obesity causes:
• peripheral insulin resistance
• resulting in hyperinsulinaemia
Impact of obesity on fertility
ovulation
PCOS and obesity have synergistic detrimental
effects on insulin metabolism

17. Impact of obesity on fertility
ovulation
• Insulin is a gonadotrophin
• Stimulating effect on the ovary similar to
luteinizing hormone (LH)
• Insulin potentiates effect of LH: even in IR
• Follicles in PCO respond prematurely to LH &
insulin which leads to follicle arrest
• So high LH or high insulin = less frequent
ovulation

18. Impact of obesity on fertility
• Spontaneous conception rate probably
reduced in ovulatory women
• Ovulation rate reduced in women with PCOS
• Ovulation induction is less successful

19. Impact of obesity on fertility
ovulation induction: clomifene/FSH
20
40
60
80
18-24 30-34 >35
BMI kg/m2
ovulationrate(%) Al-Azemi et al 2004

20. Impact of obesity on fertility
ovulation induction: LOD
20
40
60
80
<29 29-34 >34
BMI kg/m2
ovulationrate(%) Amer et al 2004100
pregnancyrate(%)

21. • Clomifene
higher dose
• Gonadotrophins
more treatment days
higher threshold dose
higher total dose
higher cost
Balen et al 2006
Impact of obesity on fertility
ovulation induction

22. • Higher risk of hyperstimulation
• Ultrasonographic monitoring more difficult
Impact of obesity on fertility
ovulation induction

23. Impact of obesity on fertility
• Spontaneous conception rate probably
reduced in ovulatory women
• Ovulation rate reduced in women with PCOS
• Ovulation induction is less successful
• ART outcomes compromised

24. Impact of obesity on fertility
all fertility treatments
30
20
10
ongoingpregnancies(%)
18-32 32-35 35-40 >40 p=0.002
BMI kg/m2
Gillett et al 2006

25. • Oocyte quality?
• Embryo quality?
• Endometrium?
• Environment?
Impact of obesity on fertility
assisted reproduction

26. Impact of obesity on fertility
assisted reproduction
Bellver et al 2010
6500 ICSI cycles / 6.4% (419) BMI > 30 kg/m2
= fertilization rate
= embryo quality (day of ET, no of embryos,
blastocyst transfers, embryo Q on D2/3)
 implantation
 pregnancy
 live birth

27. • Higher doses of gonadotrophin for
superovulation & controlled ovarian
hyperstimulation
• Higher cost
Impact of obesity on fertility
assisted reproduction

28. Impact of obesity on fertility
• Spontaneous conception rate probably
reduced in ovulatory women
• Ovulation rate reduced in women with PCOS
• Ovulation induction is less successful
• ART outcomes compromised
Probability of pregnancy, spontaneous &
assisted, is reduced

29. Impact of weight loss on reproduction
Effectiveness
Increased ovulation & pregnancy rates in obese
anovulatory women with modest weight loss
• >5% weight loss Kiddy et al 1992
• average weight loss 6.3kg Clark et al 1995
• improvement in insulin sensitivity & central fat
Huber-Buchholz et al 1999

30. Impact of obesity on obstetrics

31. • gestational diabetes
• gestational hypertension / pre-eclampsia
• miscarriage
• caesarean section
• preterm delivery
• macrosomia
• urinary tract & wound infections
• thromoboembolism
Impact of obesity on mother & baby

32. Metwally et al 2008
Meta-analysis of 16 eligible studies
• Risk of miscarriage increased when BMI
>25kg/m2 (OR 1.67, 95% CI 1.25-2.25)
Lashen et al 2004
• Risk of recurrent miscarriage increased when
BMI >30kg/m2 (OR 3.5, 95% CI 1.03-12.01)
Impact of obesity on miscarriage

33. CEMACH 2003-5:
• 28% of mothers who died were obese
• 16-19% of maternity population obese
Impact of obesity on the mother
maternal mortality

34. Impact of obesity on the offspring

35. • congenital anomaly
• stillbirth
• neonatal death
• vertical transmission
Impact of obesity on the offspring

36. Increased risks for mother and child
Impact of obesity on pregnancy

37. Stothard et al 2009
Systematic review & meta-analysis: >30kg/m2
• Neural tube defects
• Cardiovascular anomalies
• Cleft palate +/- cleft lip
• Anorectal atresia
• Hydrocephaly
• Limb reduction anomalies
Impact of obesity on congenital anomality

38. Obesity and neural tube defects
Rasmussen et al 2008: meta-analysis of 12
observational cohort studies
Odds ratio for NTD cf healthy weight
• overweight: OR 1.22 (95% CI 0.99-1.49)
• obese: OR 1.7 (95% CI 1.34-2.15)
• severely obese OR 3.11 (95% CI 1.75-5.46)

39. Folic acid
• Maternal folate deficiency associated with NTDs
• Periconception folic acid reduces 1st occurrence
& recurrence
Lumley et al Cochrane Database of systematic reviews 2001 (3)
• Risk in women with previous NTD pregnancy
reduced by 4mg/day
MRC Vitamin Study Research Group Lancet 1991 CMACE
• CEMACE/RCOG – periconception high dose folic
acid (5mg) for BMI >30

40. High dose folic acid:
unproven in obesity
• No evidence that supplementation reduces
incidence of NTDs in the obese
Ray et al 2005
• Red cell folate not significantly lower in obese
pregnant women, despite lower folate intake cf
normal weight
Mojtabai 2004
• Possible role for periconception hyperglycaemia
- High dose folate not part of ACOG preconception
recommendations for the obese

41. Vitamin D supplements
• 25% of women 19-24yo & 17% of 25-34yo at
risk of vitamin D deficiency in Britain
Office for National Statistics 2004
• Prepregnancy BMI >30 associated with
maternal vitamin D deficiency & low cord
blood levels
• Bodanar et al 2007
• Encourage obese pregnant women to take
supplements: 10mcg daily

42. Summary
• Most preconception care delivered
opportunistically
• All healthcare practitioners should be aware
of the reproductive risks of obesity and be
prepared to counsel women (or arrange
referral)
• Inter-pregnancy may be an opportune time
due to increased contact with healthcare
practitioners

43. Preconception care in the obese
• Weight reduction: realistic goals, appreciation
of time constraints
• Counsel on reproductive risks
• Supplements – folic acid, vitamin D
• Screen for diabetes when appropriate
– family history
– anovulatory PCOS
• Engage with obese women to ensure they
access appropriate care

44. lisa.webber@uclh.nhs.uk