Fergus P. Meehan

True rupture/scar dehiscence in delivery following prior section.

Fear of uterine rupture has led to the widespread practice of ‘Once a section, always a section’. Between 1972 and 1982, 1498 patients with one or more previous cesarean sections were delivered at University College Hospital, Galway. Trial of labor was undertaken in 844 patients, while the remaining 654 patients underwent repeat elective section because they had two or more prior sections. Eight true ruptures and 22 scar dehiscences were found. Regional analgesia and oxytocin did not significantly affect the rate of true rupture. The mean parity with uterine rupture was five, and it occurred most frequently in the initial trial of labor. There were four perinatal deaths associated with true rupture. Failure to detect the already compromised fetus before labor and delivery, rather than the method of delivery, was responsible for fetal demise in some instances. Five true ruptures were found in the trial of labor group (i.e. a ratio of 1 : 169), with the loss of three babies. A further baby was stillborn in a mother who ruptured a classical scar before labor. There were no maternal deaths in trial‐of‐labor patients and one in the elective section group. Two patients with true rupture had their uterus repaired, and were subsequently delivered by section. Another two patients with bloodless dehiscence and no repair, had two subsequent elective repeat sections each, and the unrepaired scar dehiscence was not evident.

True rupture of the Caesarean section scar (a 15 year review, 1972–1987)

In a 15 year period (1972-1987) a total of 2434 parturients with one or more previous Caesarean sections were delivered at University College Hospital, Galway. There were 1084 (44.5%) patients booked for elective repeat Caesarean delivery, because they had two or more prior sections (maximum number = 10) or a recurrent indication for section other than the prior section. Trial of labour was undertaken in 1350 (55.5%) patients, and 81.26% achieved a vaginal delivery. Regional analgesia was employed in 25.5% and oxytocin in 31.9%. There were 6 (0.44%) or 1:225, true scar ruptures, resulting in 1 stillbirth and 2 neonatal deaths with no maternal death. There were 4 (0.37%), or 1:271, uterine ruptures in patients booked for elective repeat section: a classical scar rupture before labour, with a fresh stillbirth; placenta praevia percreta with bladder involvement in two patients (both resulting in maternal death), and a patient with placenta praevia accreta.

Stillbirths: A Clinicopathological Survey (1972–1982)

A survey of 325 stillbirths from 27,072 babies delivered at University College Hospital Galway from April 1, 1972 to March 31, 1982, gave a stillbirth rate of 12 per thousand, which, when corrected for 66 lethal congenital abnormalities, became 9.6 per thousand. The cause of death in each stillbirth was determined clinically and pathologically where possible and was classified according to a modified Aberdeen classification of perinatal death. Consideration of the birth weights of the babies who died showed that 223 (68.6%) weighed over 1,500 g, and excluding those with abnormalities, they must be considered salvageable with the application of intensive neonatal care. There were 54 (16.6%) intrapartum deaths, which must also be considered preventable. The application of ultrasonic surveillance should complement clinical acumen, by allowing easier detection of the fetus at risk, thereby facilitating earlier intervention which in turn should reduce antenatal stillbirths.

The return of postpartum fertility monitored by enzyme-immunoassay for salivary progesterone

A longitudinal study in which daily salivary progesterone and estrone were measured by solid-phase enzyme-immunoassays was performed in 30 postpartum women to monitor the return of ovarian activity. Ovulation was inferred from a sustained rise in salivary progesterone over 251 pmol/l, but salivary estrone measurements were not as informative as progesterone in this regard. Recovery of ovarian activity was slower in lactating women compared with non-lactators; the mean delivery-menstruation interval were 123 (+/- 10) and 57 (+/- 7) days, respectively. An abnormal luteal phase was noted in 35% of the first ovulatory cycles, 20% had short luteal phases and 15% were less than the 5th percentile of a normal control corridor. The pregnancy rate in this study of 3.3% was lower than the anticipated rate of 8.8%. We conclude that salivary progesterone measurements are useful for monitoring the return of ovarian activity postnatally.

Trial of labour following prior section; a 5 year prospective study (1982-1987)

Between 1982 and 1987, 506 women previously delivered by Caesarean section were subjected to a trial of labour. Vaginal delivery was achieved in 78.6% with only 1 true rupture of the scar (0.2%). There were no intrapartum or neonatal deaths. Moreover, 7 of the 8 antepartum stillbirths were due to asphyxia, and, as the perinatal mortality rate for the study group was higher than for the overall population, the need for antenatal surveillance in previously sectioned patients is emphasized. Induction of labour was performed in 127 patients with 74.1% achieving vaginal delivery. Oxytocin was administered to 162 patients for either induction or augmentation of labour and 80.3% had a vaginal delivery, with 1 true rupture and 4 bloodless dehiscences. It is concluded that trial of labour following prior section is associated with little risk of true rupture, and with no added risk to the fetus. Our policy and management has helped maintain over the past 5 years an overall moderate Caesarean section rate (10-11%) with a low perinatal mortality rate.

Perinatal Mortality in Multiple Pregnancy Patients

A study of perinatal mortality in multiple pregnancy over a period of 12 years, 1972 to 1984, showed prematurity and low birthweight as the major causes of fetal loss. The highest risk was found at 28 to 30 weeks gestation (306/1,000). There was a significantly greater risk to babies delivered by the breech (136/1,000), and likewise in the second twin when compared with the first, ratio 1:14. A significant drop in the perinatal mortality rate, from 98/1,000 to 39/1,000, was observed between 1972-1978 and 1979-1984. Ultrasound has facilitated the earlier diagnosis of twins and provides more accurate serial fetal assessment. Bedrest, more vigilant antenatal care, intrapartum surveillance and improved neonatal care, are required to maintain and further reduce the perinatal mortality rate. When regional analgesia was employed in labour, the number of babies lost was 41/1,000, vs 93/1,000 in patients not receiving regional analgesia. External cephalic version and vertex delivery of the second twin is preferable to internal version and breech extraction. It should also be contemplated, as an alternative to elective cesarean section for a transverse lie or breech presentation of the second fetus.

The frequency of salivary progesterone sampling and the diagnosis of luteal phase insufficiency

A profile of salivary progesterone concentrations, based on daily samples taken over a full menstrual cycle, provides a detailed picture of changes in luteal function, at the expense of analyzing a large number of samples. Strain can be placed on analytical services by assaying daily samples instead of one or a few serum (or saliva) samples. This study sought to determine the minimum number of salivary progesterone determinations which adequately describe luteal function. Daily salivary progesterone levels from 215 cycles, of which 29 cycles had progesterone profiles indicative of luteal phase insufficiency, were analyzed to ascertain the efficiencies of various sampling patterns of reduced frequency. A single mid-luteal salivary progesterone estimation or the mid-luteal Lenton progesterone index (n = 4) satisfactorily reflected the normal luteal phase, but a frequency of one sample every 3 days over the luteal phase (n = 5-6) was necessary to allow recognition of a short luteal phase or poor progesterone surge.