M. Maurice Abitbol

Obstetrics and posture in pelvic anatomy

Abstract To investigate the obstetric impact on the shape of the human pelvis, the pelvic dimensions of 500 female patients were compared with regard to the duration of their gestations, and to the weight of their newborns. It was demonstrated that there is no relationship between these variables. Similar observations were made on several mammals in which the dimensions of the pelvis are not influenced by the duration of gestation or fetal weight, although they are very responsive to sitting or erect posture. The pelvis in Australopithecus was shaped more to satisfy erect posture and bipedal locomotion than to allow increase in fetal size, which occurred much later, since the encephalization process was on the way only after the pelvis had taken more or less its present shape. Adjustments of the human female pelvis to the increased size of the fetal head are minor, compared with the adjustments to erect posture, because erect posture preceded encephalisation and was therefore first to make its demands on the pelvis. The modern human pelvis is certainly tight and frequently leads to difficult delivery. Socioeconomic factors such as diet, heavy physical work in adolescence, and early pregnancy also can be contributing factors to the multiple variety of shapes in the present female pelvis.

Management of the abnormal cervical smear and carcinoma in situ of the cervix during pregnancy

Abstract A series of 286 abnormal cervical smears and 42 cases of carcinoma in situ of the cervix during pregnancy is presented. Multiple biopsies were performed on all the patients with abnormal smears, and, additionally, conizations were done when the biopsy yielded carcinoma in situ. Three cases of invasive carcinoma were found, all having been diagnosed by biopsy alone. In this series of 286 abnormal smears, subsequent conization did not yield any invasive carcinomas that had not been diagnosed from the biopsies. These data suggest that even when colposcopy is available multiple biopsies rather than conization should be the routine procedure when abnormal smears are found during pregnancy. Because of the serious complications associated with conization during pregnancy, this procedure should seldom be done and should be limited to carefully selected and specific cases.

Carcinoma of the vulva: improvements in the surgical approach.

Abstract The classical incision line for radical vulvectomies is associated with a constant sloughing in the groin and in the perineum. A new incision line is proposed which leaves a major part of the mons veneris in place and which approaches the perineum in a “butterfly” shape. This line of incision allows primary healing in most of the cases, and there has, so far, been no case of local vulvar recurrence since more tissue is removed from the perineum. Also, meticulous attention to constant drainage with negative pressure for the groin has practically eliminated the extensive slough which occurs classically in this region. The results have been a much shorter hospital stay (2 weeks average) and, to date, the absence of local vulvar recurrence.

Fetal Heart Rate and Transcutaneous Monitoring during Experimentally Induced Hypoxia in the Fetal Dog

ABSTRACT: A model of impaired oxygen delivery, using an acute surgical preparation in the fetal dog, is described. Fetal heart rate, transcutaneous pO2 and pCO2, and tissue pH were simultaneously recorded during hypoxic episodes produced by a series of successive occlusions of the maternal abdominal aorta. Corresponding values were also determined in the arterial blood of the fetus. The following pathophysiologic sequence of events was observed: 1) a latency period with no changes; 2) a drop in pO2 which stabilized later at a lower pressure; 3) late fetal heart rate deceleration, the pattern of which was not related to the progressively deteriorating fetal condition; 4) a progressive increase in pCO2; 5) a progressive decrease in pH. Abnormal tissue values consistently preceded and were more adversely affected than corresponding blood values. This experimental model demonstrates first that late decelerations of the fetal heart rate are an early sign of fetal hypoxia and second that a fall in fetal blood pH, beyond that level normally seen during labor, occurs relatively late in this pathophysiologic sequence. Between these two, there are intermediary stages that could be continuously monitored in order to identify worsening fetal condition. Continuous tissue pH and transcutaneous pO2 and pCO2 recording may potentially be of significant clinical value.

The use of an indwelling Doppler probe to study acute changes in umbilical artery waveforms in the fetal sheep

A chronic sheep model for Doppler umbilical vascular analysis was developed, in which indwelling Doppler probes were used. These were designed with a fixed angle of insonation and implanted directly on the umbilical cord to register umbilical artery velocity waveforms. The fetuses in eight pregnant ewes underwent maternal aortic and umbilical cord constrictions producing serial blood flow reductions. Occlusion of the umbilical cord and maternal aorta caused distinctly different waveforms. Cord occlusion produced an immediate response with an elevated systolic/diastolic ratio and disappearance of diastolic velocity. Maternal aortic occlusion produced a delayed response with drops in both systolic and diastolic velocity; diastolic velocity never reached zero. Although systolic/diastolic ratios are believed to reflect placental resistance, the maintenance of the systolic/diastolic ratio with diminution of systolic velocity suggests declining fetal cardiac output as an additional factor. It is possible to differentiate uteroplacental from umbilicoplacental insufficiency by Doppler methods. With technologic improvements Doppler ultrasonography may allow better analysis of acute stressful conditions during human labor.

Arterial Po2, Pco2, and pH versus transcutaneous Po2 and Pco2 and tissue pH in the fetal dog

In the fetal dog, simultaneous recording by transcutaneous PO2 and PCO2 and tissue pH electrodes were compared to corresponding arterial values during hypoxic episodes produced by occlusion of the maternal abdominal aorta. Before occlusion, the differences between the paired values were minimal. Under anoxic conditions, expected changes in the peripheral circulation were observed. However, the transcutaneous PO2 was lower, the transcutaneous PCO2 much higher, and the tissue pH much lower than in blood. Continuous electrodes demonstrate changes resulting from gas and hydrogen ion coming from cells more readily than blood because they are closer to the former. Additionally, carbon dioxide and hydrogen ion are buffered to a greater degree in blood than in cells. Consequently, under conditions of stress and active metabolism, PCO2 is higher while PO2 and pH are lower in cells than in blood. When compared with monitoring of gases and acid-base balance through blood sampling, continuous transcutaneous and intracutaneous monitoring would seem to be more representative of the environment at the cellular level.

Cesarean hysterectomy in the treatment of carcinoma in situ of the cervix diagnosed during pregnancy.

Abstract A series of 42 cases of carcinoma in situ of the cervix during pregnancy is presented. Hysterectomy was the mode of treatment in 24, and 7 of these were cesarean hysterectomies. The use of cesarean hysterectomy in the treatment of carcinoma in situ of the cervix during pregnancy is discussed. A simple technique for performing this latter type of operation is described which allows complete removal of the cervix and helps to diminish complications. No complications were encountered in this series. This suggests that cesarean hysterectomy, performed by the technique described in this report, warrants more consideration as one of the methods of treating selected cases of carcinoma in situ of the cervix during pregnancy.

Use of an indwelling Doppler probe to study acute changes in umbilical vein waveforms in the fetal sheep

A chronic sheep model for Doppler umbilical vascular analysis with indwelling probes was used for the investigation of umbilical vein velocity waveforms. Maternal aortic occlusions produced a delayed drop but never eliminated umbilical vein velocity. With umbilical cord occlusion, there was immediate umbilical vein waveform response. Sudden cord occlusion and release showed reactive venous overflow velocity at the beginning and end of occlusion. Total cord occlusion produced zero velocity, but within seconds, the flow velocity was seen despite persistent occlusion in 65% of the cases. A characteristic undulating venous waveform pattern synchronous with fetal heart rate in over half of the cases was often observed. Reduction of blood flow by uteroplacental insufficiency may be differentiated from umbilical cord occlusion.

Intrauterine Resuscitation in the Severely Distressed Fetal Dog

Severe fetal distress was produced in 16 fetal dogs by successive and/or prolonged occlusion of the maternal abdominal aorta in an acute surgical preparation, and was characterized in fetal arterial blood of 7.06 for pH, 10 mm Hg for O2, 127 mm Hg for CO2, and fetal heart rate decelerations. Five fetuses recovered spontaneously in utero and delivered normally; 3 needed maternal oxygenation before delivery; 3 suddenly died in utero; 5 fetuses were delivered while still alive in utero when the tpH reached 6.85, and eventually expired. Intrauterine recovery and resuscitation was effective in some fetuses.