Assessment of fetal wellbeing in pregnancy and labour Dr Ban Hadi

1. Assessment of fetal wellbeing in pregnancyand labourDr Ban Hadi

2. Green-top Guideline 57February 2011 Most women are aware of fetal movements by 20 weeks of gestation. Clinicians should be aware (and should advise women) that although fetal movements tend to plateau at 32 weeks of gestation, there is no reduction in the frequency of fetal movements in the late third trimester.

3. Green-top Guideline 57February 2011 Although some multiparous women may perceive fetal movements as early as 16 weeks of gestation , some primiparous women may perceive movement much later than 20 weeks of gestation

4. Factors which influence a woman’s perception of this activity 1. Fetal ‘sleep’cycles 2. Maternal position 3.Drugs, smoking 4.Maternal blood glucose 5.Administration of corticosteroids 6.Fetal malformations, position

5. Fetal movements are usually absent during fetal ‘sleep’cycles, which occur regularly throughout the day and night and usually last for 20–40 minutes. These sleep cycles rarely exceed 90 minutes in the normal, healthy fetus

6. women perceive most fetal movements when lying down, fewer when sitting and fewest while standing. It is therefore not surprising that pregnant women who are busy and not concentrating on fetal activity often report a misperception of a reduction of fetal movements. an anteriorly positioned placenta may decrease a woman’s perception of fetal movements

7. cigarette smoking is associated with a decrease in fetal activity Raised maternal blood glucose may increase fetal movements

8. The administration of corticosteroids to enhance fetal lung maturation has been reported by some authors to decrease fetal movements and fetal heart rate variability detected by cardiotocography (CTG) over the 2 days following administration

9. Fetuses with major malformations are generally more likely to demonstrate reduced fetal activity (anencephaly has more activity) Fetal presentation has no effect on perception of movement

10. Fetal position might influence maternal perception: 80% of fetal spines lie anteriorly in women who were unable to perceive fetal movements despite being able to visualise them when an ultrasound scan was performed

11. How can fetal movements be assessed? 1.Subjective maternal perception of fetal movements 2.Objective assessments of fetal movements use Doppler or real-time ultrasound

12. If women are unsure whether movements are reduced after 28+0 weeks of gestation, they should be advised to lie on their left side and focus on fetal movements for 2 hours. If they do not feel 10 or more discrete movements in 2 hours, they should contact their midwife or maternity unit immediately.

13. There is lack of clinical data of precise normal movement count Maternal anxiety is a draw back of maternal fetal movement counting

14. Management of women with RFM 1.History : a. Risk factors for FGR and IUD, duration of RFM b. Kick count: reassuring if 4 or more movements in 1 hr. 3 or less indicate further assessment A second approach is to have the mother begin counting fetal movements when she wakes up in the morning and record the number of hours required to feel 10 movements. On average, this takes 2 to 3 hours. Again, maternal reports of decreased movement should prompt further testing

15. 2.Examination: The key priority when a woman presents with RFM is to confirm fetal viability. In most cases, a handheld Doppler device will confirm the presence of the fetal heart beat General: BMI, general health Vital signs: blood pressure Abdominal exam. measurement of symphysis–fundal height to detect SGA fetuses

16. 3.CTG :Non stress test After fetal viability has been confirmed and history confirms a decrease in fetal movements, arrangements should be made for the woman to have a CTG to exclude fetal compromise if the pregnancy is over 28+0 weeks of gestation

17. At least two or more accelerations with fetal movement in 20 min. by at least 15 bpm for 15 sec. is considered as reactive NST Before 32 weeks, accelerations are defined as having an acceleration that is 10 bpm or more above baseline for 10 seconds or longer .

18. A reactive NST is highly predictive of low risk for fetal mortality in the subsequent 72 to 96 hours and is still predictive at 1 week. Fetuses do not routinely demonstrate reactivity before 28 weeks, and it may be normal to have a nonreactive tracing as late as 32 weeks' gestation. After 32 weeks, a nonreactive tracing should prompt further evaluation of fetal well-being, such as measuring a biophysical profile

19. 4.Ultrasound: Ultrasound scan assessment should be undertaken as part of the preliminary investigations of a woman presenting with RFM after 28+0 weeks of gestation if: 1.The perception of RFM persists despite a normal CTG or 2.If there are any additional risk factors for FGR/stillbirth.

20. Ultrasound scan assessment should include fetal biometry: the assessment of abdominal circumference and/or estimated fetal weight to detect the SGA fetus, and the assessment of amniotic fluid volume. Ultrasound should include assessment of fetal morphology if this has not previously been performed

21. 4.Ultrasound Biophysical profile: There may be a role for the selective use of BPP in the management or investigation of RFM There is evidence from uncontrolled observational studies that BPP in high-risk women has good negative predictive value; that is, fetal death is rare in women in the presence of a normal BPP

23. A score of 6 raises concern, and the BPP should be repeated in 6 to 24 hours, especially in fetuses over 32 weeks' gestation. If the score does not improve, delivery should be considered, depending on gestational age and individual circumstances. Scores of 4 or below are worrisome, and delivery should be considered, again depending on gestational age and clinical context

24. Non stress Test and Amniotic Fluid Index (AFI). This test is also known as the modified biophysical profile. In the third trimester, an AFI and NST are often used together to assess fetal well-being. The AFI is the sum of the maximum vertical pockets of umbilical-cord-free amniotic fluid in each of the four quadrants of the uterus. In general, the AFI reflects fetal perfusion, and, if decreased, raises suspicion for placental insufficiency. A normal test has a reactive NST and an AFI greater than 5 (and less than 25). An abnormal test lacks one or both of these findings.

25. Doppler study: of the umbilical and middle cerebral art.

29. A measure of the amount of diastolic flow relative to systolic is provided by several indices, such as the pulsatility index or resistance index, which essentially compare the amount of diastolic flow to systolic flow. When these indices are high, this indicates high resistance to flow; when the indices are low, resistance to flow is low

30. while a rising resistance in the fetal aorta reflects compensatory vasoconstriction in the fetal body. Absent diastolic flow in the fetal aorta implies fetal acidaemia. Perhaps the most sensitive index of fetal acidaemia and incipient heart failure is demonstrated by increasing pulsatility in the central veins supplying the heart, such as the ductus venosus and inferior vena cava.

31. Doppler ultrasound studies of the uterine arteries may demonstrate markers of increased resistance to flow including the diastolic ‘notch’ in the waveform

32. Uterine artery waveform with diastolic notch

34. 5.Contraction stress test: A positive‌ CST is one in which late decelerations occur with more than 50% of contractions. Late decelerations are decelerations that reach their nadir after the peak of the contraction. A negative‌ CST is one in which no late decelerations occur. A CST with non repetitive late decelerations is considered equivocal, and further evaluation of the pregnancy is performed. An inadequate or unsatisfactory CST is one in which adequate contractions are not achieved. Relative contraindications to CST include preterm labor, preterm premature rupture of membranes, placenta previa, and high risk for uterine rupture. Previous low transverse cesarean section is not a contraindication

35. Criteria for Interpretation of the ContractionStress Test Negative: no late or significant variable decelerations Positive: late decelerations following 50% or more of contractions (even if the contraction frequency is fewer than three in 10 minutes) Equivocal-suspicious: intermittent late decelerations or significant variable decelerations Equivocal-hyperstimulatory: fetal heart rate decelerations that occur in the presence of contractions more frequent than every 2 minutes or lasting longer than 90 seconds Unsatisfactory: fewer than three contractions in 10 minutes or an uninterpretabletracing

36. Assessment of fetal wellbeing during labour 1.History and examination

37. 2.Amount and color of amniotic fluid Clear liquore of normal amount is reassuring Absent liquore, blood stained and meconium stained liquore raise concern

38. 3. CTG: To interpret a CTG you need a structured method of assessing it’s various characteristics. The most popular structure can be remembered using the acronym DR C BRAVADO DR – Define RiskC – ContractionsBRa – Baseline Rate V – Variability A – Accelerations D – DecelerationsO – Overall impression

39. Define risk You first need to assess if this pregnancy is high or low risk This is important as it gives more context to the CTG reading

40. In the low-risk situation, intermittent auscultation, either by Pinard stethoscope or by handheld Doppler, is often advocated. Current guidelines suggest auscultating the FHR every 15 minutes in the active phase of the first stage of labour. This should be for 60 seconds following a contraction, in order to detect significant decelerations. Maternal pulse should also be recorded by palpation to avoid confusion, particularly when an FHR abnormality is suspected.

41. Contractions Record the number of contractions present in a 10 minute period – e.g. 3 in 10 Each big square is equal to 1 minute, so you look how many contractions occurred in 10 squares Individual contractions are seen as peaks on the part of the CTG monitoring uterine activity

42. Duration – how long do the contractions last? Intensity – how strong are the contractions?

46. The baseline rate: is the average heart rate of the fetus in a 10 minute window Look at the CTG & assess what the average heart rate has been over the last 10 minutes Ignore any Accelerations or Decelerations A normal fetal heart rate is between 110-160 bpm

48. Foetal Tachycardia Foetal tachycardia is defined as a baseline heart rate greater than 160 bpm It can be caused by: Foetal hypoxia Chorioamnionitis – if maternal fever also present Hyperthyroidism Foetal or Maternal Anaemia Foetal tachyarrhythmia

50. FoetalBradycardia Foetalbradycardia is defined as a baseline heart rate less than 110 bpm. Mild bradycardia of between 100-110bpm is common in the following situations: Post-date gestation Occiput posterior or transverse positions Severe prolonged bradycardia (< 80 bpm for > 3 minutes) indicates severe hypoxia