Piet C. Struijk

Risk factors for third degree perineal ruptures during delivery

Objective To determine risk factors for the occurrence of third degree perineal tears during vaginal delivery.

Anal sphincter damage after vaginal delivery: Functional outcome and risk factors for fecal incontinence

Objective. To assess the role of anal sphincter damage following delivery in the development of anorectal complaints and urinary incontinence, and to identify obstetric factors associated with subsequent fecal incontinence.

Umbilical artery waveform analysis based on maximum, mean and mode velocity in early human pregnancy

The objective of this study was to identify the best method for reconstructing blood-flow velocities from the early human umbilical artery to determine the physiological changes in fetal blood-flow velocity and heart rate. Pulsed Doppler recordings from the umbilical artery with a duration of approximately 7 s were made at 10-20 weeks of gestation. For reconstruction of the blood-flow velocity from the Doppler audio signal, the maximum (envelope), mean and mode frequency reconstruction methods were used. For the assessment of variability in blood-flow velocity and heart rate in the umbilical artery, the maximum velocity reconstruction method is preferred because it is relatively insensitive to noise, nonuniform insonation, and wall filter settings.

Maternal and fetal cardiovascular responses to strenuous bicycle exercise

In a longitudinal study we investigated some cardiovascular responses to strenuous bicycle exercise in 33 healthy women during pregnancy and the postpartum period. The exercise electrocardiogram demonstrated depression of the ST segment in 12% of women in the absence of clinical signs of ischemia, and the incidence of these changes was unaffected by pregnancy. In spite of slightly different blood pressures at rest during the first and second trimesters of pregnancy, the blood pressure response to exercise at approximately 75% Vo2max was virtually unaffected by pregnancy. After a maximal bicycle test, the fetal heart rate was increased by an average of 4 beats/min, without a change in pattern. Tocodynamometry suggested a transient increase in uterine activity after maximal exercise in 6% of the tests. These findings support the view that strenuous exercise of limited duration is not harmful to the healthy mother and fetus.

Anal sphincter damage after vaginal delivery: Relationship of anal endosonography and manometry to anorectal complaints

AbstractPURPOSE: This study was designed to assess the relationship of anal endosonography and manometry to anorectal complaints in the evaluation of females a long time after vaginal delivery complicated by anal sphincter damage. METHODS: Thirty-four patients with anal sphincter damage after delivery, 22 with and 12 without anorectal complaints, and 12 controls without anorectal complaints underwent anal endosonography, manometry, and rectal sensitivity testing. Complaints were assessed by questionnaire, with a median follow-up of 19 years. RESULTS: Median maximum anal resting pressures were significantly lower in patients with anal sphincter damage with complaints (31 mmHg) than in controls (52 mmHg; P < 0.001). Median maximum anal squeeze pressures were significantly lower in patients with (55 mmHg) and without (69 mmHg) complaints than in controls (112 mmHg; P < 0.001 for both). Maximum anal resting pressures were significantly lower in patients with anorectal complaints after anal sphincter damage than in patients without complaints (P = 0.02). Results of anal manometry showed a large overlap between all groups. Rectal sensitivity showed no significant differences between the three groups. Persisting sphincter defects, shown by anal endosonography, were significantly more present in patients with anal sphincter damage after delivery with (86 percent) and without (67 percent) complaints than in controls (8 percent; P < 0.001 and P < 0.01, respectively). No differences in the number of echocardiographically proven sphincter defects were found between patients with or without anorectal complaints after anal sphincter damage CONCLUSIONS: Echographically proven sphincter defects are strongly associated with a history of anal sphincter damage during delivery. Sphincter defects are present in the majority of patients with anorectal complaints. Anal manometry provides little additional therapeutic information when performed after anal endosonography in patients with anorectal complaints after anal sphincter damage during delivery.

Assessment of fetal liver volume and umbilical venous volume flow in pregnancies complicated by insulin-dependent diabetes mellitus

Objectives To determine fetal liver volume and its relation with umbilical venous volume flow and maternal glycosylated haemoglobin (HbA1c) in pregnancies complicated by diabetes mellitus type I.

Fetal heart rate and uterine contractility during maternal exercise at term.

OBJECTIVE Our aim was to assess the physiologic response of human fetal heart rate and uterine contractility to moderately strenuous maternal exercise. STUDY DESIGN We measured fetal heart rate and intrauterine pressure with the use of internal monitoring before, during, and after maternal exercise at a heart rate of 140 beats/min on a cycle ergometer in 30 term women admitted for elective induction of labor. The fetal heart rate tracings were assessed by three observers and were classified according to Fischer et al. and Nijhuis et al., and the frequency and intensity of uterine contractions were determined. RESULTS Fetal outcome was good in all cases. There were no significant differences in Fischer scores between rest, exercise, and recovery periods. The fetuses displayed a heart rate pattern A and B, indicative of behavioral states 1F or 2F, 85% of the time, with state changes apparently independent of exercise. Uterine activity increased significantly during the exercise period, with a 5.5-fold increase in contraction frequency and a fourfold increase in time-pressure integral compared with rest, with rapid recovery after the exercise. CONCLUSION Exercise in healthy pregnant women at term does not cause a change in fetal heart rate pattern suggestive of fetal distress or a change in fetal behavioral pattern, but it does significantly increase uterine activity.

Fetal brain/liver volume ratio and umbilical volume flow parameters relative to normal and abnormal human development

To estimate fetal brain volume from head circumference and published postmortem data; to determine normal values for the fetal brain/liver volume ratio relative to gestational age; to establish the relationship between the brain/liver volume ratio and fetal circulatory parameters during normal and restricted (SGA) fetal growth.

Hemodynamic Parameters of Stage 20 to Stage 35 Chick Embryo

ABSTRACT: Hemodynamic parameters of the chick embryo from stage 20 (3 d of a 21-d incubation) up to stage 35 (8 d) are described. Normal values of dorsal aortic flow velocity wave forms were measured with a 20-MHz directional-pulsed Doppler velocity meter that was validated to be accurate above 5 mm/s. An analysis of variance was carried out for each of the flow velocity parameters. The correlation coefficient that represents the reproducibility was satisfactory (r > 0.90). There was a 17-fold rise in mean dorsal aortic blood flow (mm3/s). Heart rate doubled from 123 ± 12 to 239 ± 8 bpm, and stroke volume increased from 0.14 ± 0.08 to 1.28 ± 0.55 mm3. A stage-related rise was seen in peak systolic and mean velocities and peak acceleration. These data may serve as a basis for flow velocity wave form investigation and interpretation in developmental stages of cardiac malformations.

Pulse pressure assessment in the human fetal descending aorta

Pulsatile vessel diameter recordings were obtained at two different levels of the fetal descending aorta in ten third-trimester human fetuses using an echo-tracking system. A derivation of the Moens-Korteweg equation was used to estimate the pulse pressure amplitude in this vessel. The positive phase of the first derivative of the diameter curves was cross correlated to assess the propagation time of the pulse wave. It is postulated that this method minimises the measuring errors resulting from diameter pulse wave changes during propagation along the longitudinal axis of the descending aorta. It was estimated from repeated measurements that approximately 13 recordings of 5.2 s each are required to assess the mean pulse pressure amplitude for an individual fetus with an estimated random error of 10%.