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| Year : 1985 | Volume
: 31
| Issue : 2 | Page : 98-101 |
Management of post-term pregnancy.
Karande VC, Deshmukh MA, Virkud AA
How to cite this article:
Karande V C, Deshmukh M A, Virkud A A. Management of post-term pregnancy. J Postgrad Med 1985;31:98-101 |
Last menstrual period is the best physiological land mark to assess the gestational period in pregnancy. However, a few women are sure of their dates and often cause anxiety when they come with postdatism. A post-term pregnancy is the one which extends beyond 42 weeks or 294 days from the first day of the last menstrual period.[11]
Post-dated pregnancy always poses a high risk, as there is a possibility of foetal distress and death due to progressive foetal hypoxia following plancental insuffiency as a result of its agening. This is however a rare complication as usually there is enough reserve. Although it appears desirable for the pregnancy to be terminated before such a problem arises, it is not always possible to do so as there is a significant number of patients where obstetric dates are not well substantiated; further, when pregnancy reaches 42 weeks, there are patients with a cervix unfavorable for induction and in whom induction results in a high caesarean section rate.
Eighty-five patients were studied over a period of 5 years from 1978 through 1982 in one of the units of the Department of Obstetrics and Gynaecology at the K.E.M. Hospital, Bombay. Patients who were sure of their dates and had gone 10 days beyond their expected date of delivery were studied. After admission to the antenatal ward, the maturity of the foetus was determined so as to avoid any premature induction. X-rays of the abdomen were taken in all 85 patients to confirm the maturity of the foetus. However, 15 cases went into spontaneous labour within 48 hours of admission and hence further monitoring could not be done in these patients. Ultrasound examination, Nile blue cell count,[2] lecithin/sphingomyelin ratio[8] and amniotic fluid creatinine estimation[10] were carried out in the remaining 70 cases. Amniocentesis could be done only on 39 cases as the remaining cases refused the procedure.
A conservative approach to the problem was chosen. Patients were kept under observation and foetal well-being was monitored by urinary oestriol levels,[9] nonstress tests[12] done biweekly and foetal movements[13] checked daily.
There were a total of 3200 deliveries in the unit during the last 5 years of which 85 cases showed post-datism, thus giving an overall incidence of 2.6%. [Table - 1] depicts their gravidity in relation to their age.
Ultrasound examination showed a biparietal diameter between 9.1 and 9.3 cm in 30 cases and between 9.4 and 9.5 cm in 40. Nile blue cell count, lecithin/sphingomyelin ratio and amniotic fluid creatnine confirmed the maturity levels. The urinary oestriol levels were more than 4 mg per 24 hours and the foetal movements were more than one per hour in all. In the non-stress test, 8 cases showed a nonreactive pattern and hence they further underwent an oxytocin challenge test.[7] Four of these showed this test to be positive. Amniocentesis done in these 4 cases showed meconium-stained liquor and hence they were taken up for elective caesarean section. The remaining 66 cases were further assessed. for the favourability of induction by Bishop's score.[1] Twenty six of these had a Bishop's score of 7 or more and were induced by stripping of membranes and a simple enema.[3] Twenty of these went into labour when enema was repeated after 24 hours. The remaining 6 patients were started on a slow pitocin drip and were delivered within 24 hours. Forty patients who were not induced because of their Bishop's score being less than 5 were monitored for foetal well-being without any interference. All these remaining cases went into spontaneous labour within the next 7-14 days. [Table - 2] shows the mode of delivery and duration of their pregnancy.
Of the 55 patients who went into labour spontaneously, 48 delivered vaginally of which six were outlet forceps deliveries. The remaining seven were caesarean sections. Of the 26 patients undergoing induction of labour, 22 delivered vaginally and 4 were taken up for caesarean section. Thus eleven cases had an emergency caesarean section whereas 4 had elective procedure thus making a total of 15 caesarean sections (17.6%). [Table - 3] depicts the details of these 15 cases.
[Table - 4] shows the detailed outcome o: all 85 cases.
All the babies after birth were checked for signs of post-maturity according to Clifford's criteria.[5] Six babies showed definite sings of post-maturity; of these, one was delivered by elective section at 42 weeks. The rest 5 were all beyond 42 weeks; 3 of these were born to mothers going into spontaneous labour and two to those who were induced. There were 2 perinatal losses. One was a fresh still birth. One of the patients under observation went home against medical advice but came back within 7 days with advanced labour and absent foetal heart sounds. She was delivered a still birth baby with multiple loops of cord around the neck. Another baby had multiple congenital anomalies which were incompatible with life and the baby died on the second day after birth.
All tests on liquor amnii are tests of maturity for certain organs and hence they are the indirect indices of overall foetal growth in utero[6] Campbell's modification of ultrasonic method of biparietal cephalometry carried out between 20eth and 30eth week of gestation in competent hands can correctly assess the maturity to within ± 9 days in 95% of cases.[4] Unfortunately, the accuracy falls off markedly as term approaches.[6] Thus, none of the tests done before delivery could predict post-maturity of the foetus. The virtue of antepartum tests is the high predictivity of normal outcome by the normal test results and on the assumption that a normal test result would permit the pregnancy to continue.[14] Dignosis of post-maturity had to be confirmed after delivery by the Clifford's criteria. On this basis, 6 out of 85 cases showed definite signs of postmaturity.
Clifford [5] has described three intensities of abnormality in post-term infants as a consequence of placental insufficiency. The mildest changes are: (a) desquamating loose skin, (b) long nails and (c) abundant hair. More severe foetal com promise results in meconium-staining of the amniotic fluid, skin, vernix and membranes. In the most severe stage, all the above changes are more marked and the nails and the skin are stained bright yellow. Of the 6 post-mature babies in our series, only one belonged to the severe group whereas the rest 5 were in the moderately affected group.
During the study period of 5 years, there were 23378 deliveries in the K.E.M. Hospital, with 1196 caesarean sections, giving an overall caesarean section rate of 5%. In the present series, the C.S. rate was 17.6%. Yeh and Read,[14] in a similar study of 880 patients, had the C.S. rate of 15.8% and they reported 8 perinatal losses.
Apparantly, the rule that "duration of pregnancy should be 280 days" does not apply to all with an unfavourable cervix. These cases can be conserved with proper monitoring. However, the absence of baseline variability of foetal heart rate, reduced foetal movements and the presence of meconium are ominous signs and mean that the foetus is in danger requiring close observation and selective intervention when one or more tests become abnormal. The last word has not been said about post-maturity.
We thank the Dean, K.E.M. Hospital and Seth G.S. Medical College and Dr. V. N. Purandare, Honorary Professor and Head, Department of Obstetrics and Gynaecology, K.E.M. Hospital, for allowing us to publish the hospital data.
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