Lecture of old pregnancy

2021-03-22 12:00 AM

Diagnosis and management of old-term pregnancies are very important because neonatal mortality is high, 3 times higher than that of babies born between 38 and 41 weeks.



The average gestation time is 9 months 10 days or 285 days (10 days from the first day of the last menstrual period).

Pregnancy is termed when the theoretical gestational age exceeds 42 weeks or 294 days.

Old pregnancy

Old pregnancy


Approximately 3 to 12% of pregnancies exceed 42 weeks, but in reality, the rate of senile pregnancy does not exceed 4% (due to not remembering the exact last menstrual date or the time of delayed ovulation).

The rate of maternal-fetal complications increases with gestational age, perinatal mortality rate increases from between 41 and 42 weeks, double at 43 weeks, and 4-6 times higher at 44 weeks compared to term gestation.

Complications for mothers, even cesarean section, are also doubled with bleeding, infection, and bruising.

Diagnosis and management of old-term pregnancies are very important because neonatal mortality is high, 3 times higher than that of babies born between 38 and 41 weeks.


The cause of this pregnancy is still unknown. However, there are a number of risk factors such as infarction, placenta sulfatase deficiency, prolonged use of progesterone, history of overdue birth.

The most common cause is inaccurate gestational age calculation.


Placenta and amniotic fluid play an important role in the transport and biological metabolism of the fetus. During the old pregnancy, the amount of amniotic fluid decreases gradually, the placenta cake degenerates gradually, leading to a decrease in blood flow in the placenta cake and nutrients to the fetus. Consequently, the fetus has a chronic failure in the uterus and may die in the uterus or die during labor (due to uterine contractions). Therefore, old pregnancy is a threatened pregnancy, lack of oxygen is the main cause of fetal failure, when the fetus is born alive, it shows special damage in the form of thinness, dehydration, wrinkled skin. 



Asking medical history to determine the gestational age:

Last sutra: take the landmark as the first day of the last menstrual period to calculate gestational age.

Time of fertilization: if infertility is used, this is a very valuable milestone to diagnose gestational age.

First obstetric visit: if there is a biological reaction, or an ultrasound to diagnose an early pregnancy (in the first trimester), it is very valuable.

Time of gestation: the comparison is usually at 18 weeks, and 16 weeks.

The abrupt reduction in fetal movements in pregnant women who are heavily peddled must be seriously considered.

Uterine high:

Measurements of uterine height decreased over the next 2 visits with decreased amniotic fluid (suggestive).

Additional testing

Early ultrasound (especially in the first trimester) helps accurately diagnose gestational age.

A late ultrasound is less accurate, but a low amount of amniotic fluid and calcified placenta suggests a diagnosis.

Doppler: This method allows the investigation of the fetal hemodynamic status and placenta circulation to predict fetal failure.

Pregnancy monitoring for chronic fetal failure (Nonstress test twice a week or constraction test).

Amniocentesis: look for signs of chronic pregnancy failure, yellow or green amniotic fluid may be seen.

Amniocentesis: only for confirmation of the fetus is mature, does not allow diagnosis of old-term pregnancy.

X-ray to find the ossification point: Béclard's point (head below femur). TOD score (the head-on tibial plateau). A relatively high rate of false negatives is rarely used today.

There are currently no standards that allow for certain confirmation of an old pregnancy, but it is best based on:

The last day of the sutra.


Amniotic fluid: Less amniotic fluid.

Having ruled out major gestational age errors, the only possibility remains is to closely monitor late in pregnancy to detect fetal failure.

Anyway, all pregnancies exceeding 41 weeks and 3 days are subject to follow-up and midwifery consultation with an obstetrician.

Complications of overdue pregnancy 

Risks for mother

Increased likelihood of cesarean section and delivery with surgical intervention.

Postpartum bleeding.

Long hospital stay and many complications.

Risk for pregnancy

Amniotic fluid (placenta deficiency):

Squeeze the umbilical cord.

Pregnancy failure.

Sudden fetal death.

Pregnancy maturity disorders:

(accounting for 10-20% of over-term pregnancy).

Gut inhalation syndrome:

25-30% of 42-week pregnancies have meconium in the amniotic fluid.

Adult pregnancy:

Causes difficulty delivery, bone damage, and fracture and leaves local and long-term neuropathy.

Tracking and handling

Commune level

Transfer pregnant women to higher levels after counseling.

District level or higher


If the gestational age is over 41 weeks and must be closely monitored, the woman will be determined the maturity and health status of the fetus.

Guide the patient to monitor fetal movements, and guide pregnant women to count fetal movements starting at a certain time of day. The fetus normally moves more than 10 times over a 12-hour period. A sudden decrease or decrease in the number of movements is a sign of fetal failure.

For example, after 2 hours without seeing the fetus need to be vigilant. After 12 hours, the fetus has not been found, possibly the fetus is dead.

Monitoring the amniotic fluid index by ultrasound: The fetal ultrasound checks the amniotic fluid at least 2 times/week. Amniotic fluid is defined as the amniotic fluid index ≤ 5 or the largest amniotic fluid index ≤ 2 x 2cm). Amniotic fluid is associated with a higher risk of fetal failure and neonatal mortality.

Monitor pregnancy failure with a monitor: two of the most commonly used are the non-stress test and the contraction stress test such as the nipple test or oxytocin infusion test. This test is done 2 times a week. Indicates cesarean section if Dip II occurs.

Termination of pregnancy:

In the case of a rare or mismatched pelvic head, a cesarean section is recommended.

If there is a fetal failure: cesarean section.

In other cases such as an adult fetus, the fetus is not impaired, conduct a prick test, if positive, a cesarean section is required. If negative, labor induction must be initiated and the Bishop's score assessed to predict the likelihood of inducing labor.

The Bishop Index.


0 points

1 point

2 points

3 points

Cervical opening (cm)


1 - 2

3 - 4

5 - 6

Cervical erasure (%)


40 - 50

60 - 70

≥ 80

Birth of the fetus



-1 - 0

+1 - +2

Cervical density





The direction of the cervix





If the cervix is ​​open, the Bishop is above 5, inducing labor by transmitting Oxytocin. During the urge to have fetal cardiac monitoring to be closely monitored because the fetus can fail very quickly.

If the cervix is ​​not open, the Bishop score is less than 5, it should be combined with other investigative methods such as monitoring of fetal movements, ultrasound to assess amniotic fluid reading, monitoring to decide to induce labor or follow up.

In the case of induction of labor, soften the cervix with vaginal misoprostol 50mcg.

If the transfer fails or the fetal failure occurs, a cesarean section is also required.

Take care of your baby

It is necessary to check whether the baby has to peel skin, placenta, amniotic fluid. When it is determined that the fetus is old, it is necessary to take special care measures, carefully absorb the respiratory tract, adjust metabolic acidosis, inject Vitamin K1, preventive antibiotics ... and monitor the child's development.

Note: Diagnosis of old pregnancy is based on suspicious signs. Therefore, it is required that the physician must closely monitor the patient and decide on the right management, avoid interventions on an under-term fetus, but also do not allow fetal failure and fetal death in the womb. Aging and degrading placenta.