How to diagnose Foetal growth Restriction in an unbooked case with uncertain LMP ?

 

How to diagnose  Foetal growth Restriction  in an unbooked case with uncertain LMP ?Clinical problem :  An unbooked case presented at ER  with decrease of DFMC : One should insist on NSTà if   abnormal    NST   or abnormal  BPP ( Biophysical profile) at about 33 weeks -should we jump on induction ?

 Answer is No. We have to establish gest age  ( as she is an unbooked case) & exclude existence of  possible FGR  :--then we have to accept the protocol of standard management   of  what we call as “ suspected IUGR with suspected Foetal compromise “:

However a brief outline of day to day management of such a case is mentioned below and pointed as  Flow  charts

The first suspicion of FGRà usually comes from Clinical examination  e.g 1) Low Symphiso-Fundal Ht(  SFH in cm) calculated  from stated LMP of unbooked case  , tone (feel) of uterus and maternal abdominal  circumference matched for known and certain gest age verified from first trimester USG if booked cases only .

2) FGR can also be suspected if third trimester EFW as mentioned in USG report page of unbooked case   . But if lower per centile of foetal wt is mentioned that may be due to constitutional / real FGR :

3) Is all the foetal biometry symmetrical? Then possibility is more of “Wrong date or symmetrical FGR ( mind you dear members we are dealing with an unbooked case)” .

4)  To get it confirmed about real FGR,  2 D should  suggests AC or EFW will be  < 10 centile then diagnosis of FGR is almost certain . But such per centile is possible only when Gest age have been assigned earlier at first trimester. Otherwise the notion of < 10 th centile remains a matter of speculation.

In our vast country it is difficult to have routine first trimester USG for preg dating to all women .Admittedly, there are several clinical methods of assessing Foetal growth & well being like good  DFMC, reasonably normal audible regular FHS .

What are the warning symptoms / Signs ? But there are few alarming symptoms or signs as well which are often called nonreassuring signs .These are   1) tightening of uterus 2) increasing white discharge(though not a symp of FGR but is a presumptive  symp of Preterm labour/ Early PPROM)   3) less Foetal movement as perceived by the mother(DFMC) .

 All such symptoms warrant due attention. Coming back to the different available    biophysical methods like A) NST or B) BPS.  sadly, these are full of false positive and may even be false negative interpretations. But whatever it may be, as a clinician such symtomatic   triad of decreased a)  DFMC, b) Preterm Ut contractions and c) progressive white discharge warrant a careful and possibly fortnightly assessment.

Q.1;-How to diagnose FGR in USG? :à If 2 D suggests AC/ EFW is < 10 centile then one can consider possibility of FGR.

Q. 2.  FGR -What step next?? Ans;- AC/ EFW < 10^th per centile –Doppler evaluation , estimation of  AFI, MVP(Mean vertical Pocket) . There will be some change in Doppler flow like reduced diast flow in umbilical arteries. AFI may be suboptimal .

Q.3 :- Having diagnosed  FGR(IUGR) from different biometry  like lagging of AC /EFW then next step on the part of clinician is how safe is the foetus in utero ??  Is fetoplacental unit functionally good or compromised and therefore early delivery is indicated?

 Ans- Umbilical A Doppler study:à will offer some informations this but we have to take into account of other parameters as well. Put in such situation the relevance of Umb A Doppler becomes an urgent necessity. In fact for last three decades   umbilical artery Doppler   studies has been considered as the better ability to pick up & predict poor condition of Foetus in utero( uteroplacental Insuffiency and downstream resistance in placental bed)  & possible poor perinatal   outcome in FGR   fetuses.

For instance an increased S/D ratio in the umbilical artery   is indicative   of increasing placental bed resistance and possible   fetal   compromise. A patient   with raised S/ D ratio can be monitoredà by   serial Doppler studies but how long??

Till

1.                   37  weeks maturity

2.                   Absent or  reversed diastolic flow

3.                   Reversal of Doppler   velocities in ductus venosus   during atrial contractions.

4.                   Appearances of Pulsations in Umbilical veins

But by that I do not mean this is a rule of thumb .However these are the usual sequential changes in blood FVW (Flow velocity waveforms)  which should be taken in consideration with  her age, mode of conception, (?ART),  NICU facility,  and  associated medical disorders and concomitant drug therapy .

Taken all factors together the date of delivery (usually elective CS) is planned.