Post Term pregnancy and complications.pptx

Postdated pregnancy for undergraduates

1. Post term Pregnancy

2. Definitions: postdates pregnancy - patient who has not delivered by end of 42nd week or 294 days from first day of last menstrual period (LMP) prolonged pregnancy - exceeds 40 weeks (280 days) from known time of ovulation

3. Incidence: 27 percent of pregnancies deliver in the 40 th and 41 st week . 5.5 percent deliver at ≥42 weeks.

4. Incidence: pregnancies dated by first trimester ultrasound examination: ≥41 weeks ranges from 5 to 11 percent ≥42 weeks is about 2 percent

5. Causes: The commonest cause is error in calculation of gestational age. Congenital anomalies like anencephaly which disrupt foetal pitutary adrenal axis and rare maternal enzyme deficiencie(placental sulphatase. In most cases cause is not known.

6. Determining Gestational Age Naegele's rule Quickening (around 16 to 20 weeks GA) Uterine size , increases with GA Ultrasound examination in the first trimester provides the most accurate dating Electronic Doppler ultrasound may detect fetal heart tones as early as 10-11 weeks‘ GA

7. Risk Factors Maternal or paternal personal history of postterm birth Nulliparity Male fetus Maternal obesity Older maternal age lower socioeconomic groups

8. Etiology Not Clear It is common in : * primigravida * previous post term pregnancy. 30% The cause may be due to : 1. low cortisol levels with post term fetal distress. 2. relative adrenocortical insufficiency leading to delay in the onset of labor & increased risk of intrapartum hypoxia or death.

9. Support for this theory is that : infants delivered following a post term pregnancies are at increased risk of : * sudden infant death syndrome. * death up to 2 years of age.

10. Etiology Wrong dates ; inaccurate LMP (most common) Biological variability (hereditary/familial) Maternal factors : Primiparity , previous prolonged pregnancy, sedentary habit and obesity, elderly multiparae

11. Cont… Fetal factors : Congenital anomalies: Anencephaly → abnormal fetal HPA axis and adrenal hypoplasia → diminished fetal cortisol response Placental factors : Sulphatase deficiency → low estrogen Male baby

12. Pathogenesis: amniotic fluid volume decreases amniotic fluid volume reaches maximum at 24 weeks, constant until 37 weeks, then decreases decreased amniotic fluid volume associated with decreased fetal movement and fetal heart rate decelerations

13. Diagnosis Menstrual history ; useful if the patient is sure about her date Clinical findings ; Weight record: Regular periodic weight checking reveals stationary or even falling weight Girth of the abdomen: It diminishes gradually because of diminishing liquor History of false pain : that subsided

14. Cont… Obstetric palpation : The following findings, taken together are helpful: height of the uterus, size of the fetus and hardness of the skull bones. As the liquor amnii diminishes, the uterus feels “full of fetus” a feature usually ass/c post-maturity Internal examination : While a ripe cervix is usually suggestive of fetal maturity, to find an unripe cervix does not exclude maturity. Feeling of hard skull bones either through the cervix or through the fornix usually suggests maturity

15. Investigations Aims are: To confirm the fetal maturity To detect placental insufficiency (fetal well being)

16. Cont… 1. To confirm fetal maturity Sonography ; Early ultrasound scan (in the 1 st trimester) can reduce the incidence of true post-maturity Amniocentesis : The biochemical and cytological parameters are helpful. However, this invasive method has been mostly replaced by sonography

17. Cont… Straight X-ray abdomen : Thickness and density of the skull bone shadow, appearance and density of the ossification centers in the upper end of the tibia (38–40 weeks) and lower end of the femur (36–37 weeks) are taken together to assess the maturity Not commonly done

18. Cont… 2. Fetal well being assessment; done by twice weekly, Nonstress test Biophysical profile (heart rate, movement, breathing, and amnionic fluid volume)

19. A. Fetal Complications Still birth rate increases significantly at term with advancing gestation. It is 0.35 /1000 pregnancies at 37 weeks While 2.12 /1000 pregnancies at 43 weeks .

20. Meconium aspiration Macrosomia Asphyxia before, during and after delivery Fractures and Peripheral nerve injury Pneumonia Septicaemia Intra cranial hemorrhage

21. Dysmaturity ( postmaturity syndrome) Incidence 20% stage 1 - alert facial expression; recent weight loss with decreased subcutaneous fat and muscle mass stage 2 - green meconium staining of skin and umbilicus, fetal distress, hypoxia stage 3 - yellow staining of nails, skin and umbilicus indicative of prolonged passage of meconium

22. B. Maternal Complications cesarean delivery rates of primary cesarean delivery 8.2% at 38 weeks 8.8% at 39 weeks 9% at 40 weeks 14% at 41 weeks (p < 0.001) 21.7% at ≥ 42 weeks (p < 0.001)

23. operative vaginal delivery 8.8% at 38 weeks 9.4% at 39 weeks 10.9% at 40 weeks (p < 0.001) 13.3% at 41 weeks (p < 0.001) 17.4% at ≥ 42 weeks (p < 0.001)

24. postpartum hemorrhage, starting at 38 weeks third- or fourth-degree laceration, starting at 39 weeks prolonged labor (> 24 hours), starting at 39 weeks chorioamnionitis , starting at 40 weeks endomyometritis , starting at 41 weeks

25. Symptoms of post-maturity in a newborn Dry loose peeling skin Large amount of hair on the head Overgrown nails Green-yellowish/brownish coloring of the skin from in- uteral passing of meconium More alert and wide-eyed

26. Induction versus expectant management: compared with delivery induction, expectant management associated with decreased mortality risk at 37 weeks gestation (relative risk [RR] 0.87. 95% CI 0.77-0.99) similar mortality risk at 38 weeks gestation (RR 1.11, 95% CI 1-1.22) increased mortality risk at 39 weeks gestation (RR 1.47, 95% CI 1.35-1.59) 40 weeks gestation (RR 1.58, 95% CI 1.45-1.71) 41 weeks gestation (RR 1.63, 95% CI 1.47-1.81) Reference - Obstet Gynecol 2012 Jul;120(1):76

27. Prevention: Recording LMP and calculating EDD at the time of first ANC visit. Routine early ultrasound for dating of pregnancy. Review of antenatal card and ultra sonographic reports in terms of fetal growth. Sweeping of membranes from 38 wks onwards decreases number of pregnancies going beyond 41 and 42 wks. As soon as prematurity is ruled out in high risk cases induction of labour will prevent post maturity.