Post term pregnancy

An overview on post-term pregnancy

1. POST-TERM PREGNANCY Joyce F. Mwatonoka, MD April 2018

2. Outline Introduction Etiology Diagnosis Investigations Complications Management Sxs of post-maturity in a newborn Prevention

3. Introduction Post-maturity or post-term pregnancy is a pregnancy continuing beyond two weeks of the expected date of delivery (> 294 days/>42 completed weeks) Average incidence is about 3-12% (10%) Many suspected post-term pregnancies are actually wrongly dated

4. 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

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

6. 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

7. 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

8. 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

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

10. 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

11. 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

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

13. Complications to the fetus/newborn Big baby ( macrosomia ) Placental insufficiency, which might cause; - oligohydramnios (decreased amniotic fluid), which might lead to IUGR, deformation and increased risk of cord compression -poor oxygen supply Meconium aspiration syndrome Hypoglycemia Antepartum stillbirth

14. Maternal complications An increase in severe perineal injury related to macrosomia and operative delivery which is also related to higher risk of hemorrhage, endometritis and thromboembolic disease Increase in labour dystocia

15. Management Before formulating the plan of management one should be sure of the Gastational Age Induction of labour (likely) Expectant management, with regular ultrasound and biophysical profile

16. 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

17. Prevention Women should keep truck of their menstral cycles Ultrasonography in the 1 st 12 weeks most important

18. References ; DC Dutta’s text book of Obstetrics Emedicine.medscape.com NMS Obstetrics and Gynaecology , 6th Edition Obstetrics by 10 Teachers 16 th Edition