Coasting: Helpful

or Costly Mistake?

Dr Santosh GuptaMBBS,MS,FRM

Consultant, Reproductive Medicine

Ovarian Hyper-Stimulation Syndrome (OHSS)

• Serious

• Iatrogenic

• Severe OHSS can be lethal(0.1 – 2%)

Preventive strategies

• Prior to stimulation

• During stimulation

• After stimulation

Coasting

Nautical terminology

Nature Coasting

What is Coasting?

• Withholding gonadotropins with continuation of agonist or antagonist

• Drug holiday/ no stimulation

Principle

• Withholding Gonadotropins

• Apoptosis of small & medium follicles, larger follicles continue to grow

• Lesser granulosa cell population

• Reduce release of Vascular Endothelial Growth Factor-VEGF /vasoactive substances

• Lesser chance of OHSS

Serum E2 during coasting

• Classically 1st day of coasting E2 increases• Start falling gradually after 1.7days

When to start…….?

Three factors

• Serum estradiol level(reflects the functional granulosa cell population)

• Number of follicles (predicts potential for further granulosa cell proliferation and rise in E2)

• Diameter of leading follicle

CoastingTypes

• Early coasting :When growing follicles of intermediate size 12 -15 mm

• Late coasting:Growing follicle>15mmLarger follicles less dependent on FSH

Coasting… systemic review

Coasting …….

• Reduces severe OHSS

• Reduces /eliminates cycle cancellation

• Reduces cost of therapy

• More chances of fresh transfer

• Thus offers best chance in index cycle

• Reduces distress of cancellation , OHSS and

cryopreservation of all embryos

Coasting may spoil cycle outcome..???

Days of coasting(Mansour et al, 2005)

Is early coasting feasible……??

Early and late coasting Chen Chao et al ,fert sterl 2003

Coasting in PCOS when E2 level >1500 but <3000pg/ml

(Egbase et al, human reprod 2002)

E2 on coasting D1 1943±693

E2 on coasting D2 2526±1063

E2 on coasting D3 2169±9753.6

No of follicles 25.2±4.1

No of oocytes retrieved 16.5±3.6

Fertilization rate 74%

Cleavage rate 88%

No of embryo transferred 2.4±0.2

Clinical pregnancy rate 45%

Severe OHSS nil

All pts PCOS with high BMI

Does it really reduces OHSS……?

coasting with antagonist ???

Antag coasting

Antagonist coasting

• Long protocol with hyper-stimulation can be coasted with antagonist switching resulting in rapid fall in E2

• Mean coasting days were significantly less in antag gp(1.74 vs 2.82,p value<0.0001)

• No significant difference in clinical pregnancy rate

(Aboulgar et al 2011, fert sterl)

Will it spoil my embryos……..??

Coasting and endometrial receptivityV. Ifaza ,Garcia et al, hum rep, 2002

• Coasting might impair endometrial receptivity

• Prolonged coasting associated with luteinization of endometrium

• Poor endometrial receptivity d/t high E2 level

• Thus embryo quality and implantation potential is best studied in recipients having donor oocytes from coasted vs non coasted donors

Embryo Quality in Coasting

recipient Coasted donor Non coasted donor P value

M II oocytes 6.9 7.4 ns

Fertilization rate 80.7% 83.3% ns

Cleavage rate 92% 96% ns

Embryos transferred/pt 2.6 2.9 ns

Implantion rate 22 27.7 ns

Preg rate 52.9% 54.5% ns

When coasted more than four days implantation rate was significantly low in coasted donor group probably due to bad quality oocytes /embryosImplantation rate 30.5 % vs 11.3% (p value<0.005,sign)Pregnancy rate 72% vs 37% (p value <0.005,sign)

Ifiza etal , hum rep 2002

Can we stop agonist also….???

Step Wise Integrated Approach

• Tailor made protocol• Lesser dose Gn• Step down• Coasting• Low dose hCG/ agonist trigger• Albumin/bromocriptine• Cryopreservation

Take home message

Coasting is one of the very important tool to prevent OHSS without

compromising clinical outcome

Coasting is equally feasible with antagonist protocol

Thank you

Have

safe

stimulation