Postterm Pregnancy Associate Professor Iolanda Blidaru, MD, PhD.

Prolonged pregnancy = postterm pregnancy Prolonged pregnancy = postterm pregnancy = postdate pregnancy = postdate pregnancy It is one that has lasted longer than 42 weeks or 294 days beyond the first day of the last menstrual period DEFINITION

20 % cases of prolonged pregnancy are associated with: 20 % cases of prolonged pregnancy are associated with: 1.Meconium - stained amniotic fluid 2.Oligohydramnios 3.Fetal distress 4.L oss of subcutaneous fat 5.C racked skin Post-maturity syndrome

Etiologic Factors The most frequent – an error in dating. When truly exists, the cause usually is unknown. Risk factors Primiparity Prior postterm pregnancy

Etiologic Factors Rarely, it may be associated with placental sulfatase deficiency fetal abnormalities (anencephaly, adrenal hypoplasia, absence of pituitary gland). male sex. genetic predisposition.

Using the definition of 294 days, the incidence of postterm pregnancy is %. Using the definition of 294 days, the incidence of postterm pregnancy is %. I NCIDENCE

Fetal risks The perinatal mortality > 42 weeks twice that at term > 43 weeks > 6-fold that at term

Uteroplacental insufficiency → fetal distress, hypoxia, growth restriction fetal distress, hypoxia, growth restriction Oligohydramnios - risk for cord accidents Oligohydramnios - risk for cord accidents meconium aspiration meconium aspiration Macrosomia - labor abnormalities, shoulder dystocia Macrosomia - labor abnormalities, shoulder dystocia Sudden infant death syndrome (death within the first year of life). Fetal risks

Maternal risks 1) 1)Labor dystocia 2) 2)Severe perineal injury related to macrosomia 3) 3)Increased rate of cesarean delivery. 4) 4)A source of anxiety for the pregnant woman.

DIAGNOSIS 1.Gestational age calculation Because actual dates of conception are rarely known, the LMP is used as the reference point. Because actual dates of conception are rarely known, the LMP is used as the reference point. The accuracy determination of gest ational age unreliable because of : The accuracy determination of gest ational age unreliable because of : 1. Irregular menses. 2. Recent cessation of birth control pills. 3. Inconsistent ovulation times.

2. Routine early pregnancy ultrasound ♣ Reduces the number of women who require induction of labour for apparent postterm pregnancy. ♣ It is recommended to all pregnant women and certainly those who do not have regular menses, for gestational age determination, prior to 20 weeks.

The available evidences are strongly in support that dating by e arly ultrasonography alone is a very accurate method for predicting EDD. The available evidences are strongly in support that dating by e arly ultrasonography alone is a very accurate method for predicting EDD.

3. Oligohydramnios US diagnosis US diagnosis  No vertical pocket > 2 cm or  Amniotic fluid index (AFI) – reduced - considered an indication for delivery.

1) 1)Gestational age, 2) 2)Absence / presence of maternal risk factors 3) 3)Evidence of fetal compromise 4) 4)Maternal options.  Successful management depends on effective counselling of women and their full involvement in the decision making process. Management options depend on

a.Inducing labour routinely at weeks gestation or b.Awaiting the onset of spontaneous labour, while monitoring the fetal wellbeing. The decision is difficu lt. The decision is difficu lt. Management of prolonged pregnancy

The condition of the fetus can change quickly → monitoring at frequent intervals. biophysical profile biophysical profile non stress test non stress test amniotic fluid index amniotic fluid index FETAL SURVEILLANCE

BIOPHYSICAL PROFILE 1. fetal heart rate acceleration 2. fetal breathing 3. fetal active movements 4. fetal tone 5. amniotic fluid volume

A.Healthy, uncomplicated pregnancy + fetal growth/ amniotic fluid normal  No elective induction of labor or serial antenatal monitoring B. Presence of maternal risk factors or evidence of fetal distress  Recommend cervical ripening and induction of labour Management at weeks gestation

A. Healthy, uncomplicated pregnancy  Inform the woman of the options and risks/ benefits of labor induction versus expectant management, and offer her labor induction.  Assess the cervical (Bishop) Score and a ripening agent (PG) prior to induction. Management at 41 weeks gestation

B. If mother declines induction, then provide expectant management  Daily fetal movement counts  Non stress test (NST) and Amniotic fluid index (AFI) twice / week to 42 weeks.  If the NST or AFI is abnormal, then initiate induction immediately Management at 41 weeks gestation Induce at 42 weeks even if NST and AFI are normal.

BISHOP SCORE 1. dilatation (cm) 2. effacement (%) 3. station 4. cervical consistency (firm, medium, soft) 5. cervical position (posterior, midposition, anterior)

۞ Amniotomy to diagnose thick meconium, if present → risk of meconium aspiration, continuous fetal assessment with electronic fetal monitoring. ۞ Complications: shoulder dystocia and need for neonatal resuscitation at delivery. Management during labour and delivery