POSTMATURITY SYNDROME-WHEN PREGNANCY EXCEEDS BEYOND TIME.
Dr Himani Gupta
Consulting Gynecologist in Kharghar, Navi Mumbai
-Pregnancy is period of joy and expectation, not just for the woman but her entire family. Getting timely labor pains and delivering normally also should be part of this joyous event.
-At times timely labor pains don’t start even at the approach of Expected Due Date-EDD which is considered to be 40 completed weeks of gestation.
-A pregnancy beyond due date comes under the category of ‘Postmaturity’ and its effect on fetus/newborn is known as ‘Postmaturity Syndrome”
-In this article we will discuss, what happens to pregnancy and fetus if pregnancy goes beyond due date.
Appearance of new born baby
-Wrinkled, patchy, peeling skin
-Long, thin body-suggesting of wasting
– Open eyes
-Old and worried look
Reason- loss of protection effects of vernix caseosa
Placental Dysfunction/ Senescence
-Placental apoptosis which is programmed cell death. This is a natural phenomenon of ageing. At 41-42 weeks of pregnancy (Gestation age), this phenomenon is happening more rapidly than at 36-39 weeks of pregnancy.
-As placental ageing is happening more rapidly, fetal oxygenation gets compromised which may lead to increased cord blood Erythropoietin levels.
-Fetal somatic (bodily) growth will continue albeit at a slower rate than 37-40 weeks. It will lead to larger fetus at birth. Paradoxically umbilical blood flow does not increase proportionally to growth of fetus- this will lead to further compromise of fetus.
Fetal distress and oligohydramnios
-Oligohydramnios (less water around baby in uterus) is a common condition associated with post-maturity syndrome. When these women go in labor chances of cord compression are high with each labor contraction of uterus. This may lead to fetal distress.
– In postmaturity, at times we see drastic reduction of fluid within 24-48 hours. It is also unpredictable, which patient will get this.
-AFI- Amniotic Fluid Index, is the term used to measure fluid around fetus
Non reassuring fetal heart rate tracing
-During labor, monitoring of fetal well-being is done by fetal heart rate monitoring. A tracing on a machine is taken out known as NST- Non-Stress Test
-After 42 weeks of pregnancy, fetus produces less urine- Oligohydramnios. This will lead to further decrease of blood flow to fetal kidneys, further decrease of urine production, oligohydramnios worsens. This is a vicious cycle.
-When women with postmaturity and oligohydramnios go into labor- because of less liquor, chances of cord occlusion are there.
– Viscous meconium- because of placental ageing and oligohydramnios there are higher chances that fetus will pass meconium (fetal stool) during labor. Fetus may inhale this meconium and that will lead to fetal lung infection- known as Meconium Aspiration Syndrome.
Fetal growth restriction
After 42 weeks of gestation, interval fetal growth is restricted. There is association of still birth and fetal growth restriction
With postmaturity, though interval growth is restricted, but fetus will continue to grow, albeit at slower pace. This will lead to macrosomia – big baby.
-Timely induction of labor after thorough check up of fetal well-being should be done.
– Twice weekly monitoring of fetal wellbeing by Ultrasound, Color Doppler, NST should be done if wait & watch policy is adopted for natural labor pains to come.
SUCCESSFUL INDUCTION POLICY
-Three parameters of cervix- Dilatation, Effacement & Consistency are considered
– Two parameters of fetal head- Station & Position are considered
It is applied to a scientific score- Bishop’s score.
A good Bishop’s score at the start of induction is a good predictor of successful, easy, non-traumatic vaginal birth with good maternal and new born condition and outcome.
However, if induction is started at no cervical dilatation and cervical length of > 3 cm, which indicates poor Bishop’s score, there are high chances of Caesarean delivery because of either failed induction, non- progress of labor or fetal distress.
Cervical ripening and induction agents
Prostaglandin E2 gel and pessary
– Stripping of membranes
All said and done, the decision to deliver a woman depends on so many factors like- the gestation age, history of patient, availability of diagnostic tests at a particular location, availability of prompt emergency medical services like NICU, Operation theatre, Gynecologist, Anesthetist, Pediatrician, Blood Bank, Ambulance, Affordability of expensive monitoring tests etc.
The decision is always an informed one where Gynecologist will explain in detail to patient and relatives, all the pros and cons of delivering patient now or wait and watch policy to deliver later.