Jan Laurin

Ultrasound measurement of fetal blood flow in predicting fetal outcome

Summary. The efficacy of fetal blood flow assessment in predicting fetal outcome was evaluated in 159 pregnancies suspected of intrauterine growth retardation (IUGR). Blood flow in the fetal aorta and umbilical vein was measured with imaging and pulsed Doppler ultrasound. Volume blood flow values and variables describing the waveform of the maximum aortic blood velocity were checked for relations to subsequent fetal outcome. A new semi‐quantitative velocity waveform variable, blood flow class (BFC), was designed and tested. The occurrence of IUGR, imminent fetal distress, a low Apgar score at f and 5 min, and a low pH in the umbilical artery and vein were adopted to characterize fetal outcome. Receiver operating characteristic curves were used to demonstrate the sensitivity and false positive rate, and the Cohens Kappa index was used to compare the predictive capacity of the various blood flow variables. BFC, describing the blood velocity waveform with emphasis on its end‐diastolic part, was found to be the most powerful marker of imminent fetal asphyxia (Kappa = 0.66) and of intrauterine growth retardation (Kappa—0.48).

Placental hstology and fetal blood flow in intrauterine growth retardation

Objective. To define the histological lesions in the placenta associated with abnormal blood flow findings and to evaluate their possible clinical significance.

Circulatory Changes in Fetuses with Imminent Asphyxia

Blood flow was measured in 11 term fetuses who were later delivered by means of emergency caesarean section because of cardiotocographic changes indicating imminent asphyxia. Blood flow was recorded in the fetal descending aorta and in the intraabdominal part of the umbilical vein by combined real-time and 2-MHz pulsed Doppler ultrasound method. In all 11 fetuses, the waveform of the maximum aortic blood velocity was changed in a typical way with elimination of the diastolic flow (zero flow). In 4 of the fetuses, a short-lasting reversal of the diastolic flow occurred. In 5 fetuses, the pulsatility index of the aortic flow was increased, and the aortic volume flow was pathologically low in 3 fetuses. In the umbilical vein, the volume flow was within normal limits in all cases. The umbilical flow, which normally is continuous and nonpulsatile, showed heart-synchronous pulsations in 3 of the fetuses. The typical changes in the aortic diastolic flow occurred 1-3 days before the onset of the cardiotocographic changes. This suggests that the changes in the fetal aortic blood velocity might be a clinically useful early sign of imminent asphyxia.

Placental morphology in relation to umbilical artery blood velocity waveforms

The association between umbilical artery flow velocity waveforms, placental morphology and arterial vascular pattern was investigated in 30 pregnant women at risk for intra-uterine growth retardation. The blood velocity waveform was assessed in the umbilical arteries with pulsed Doppler ultrasound. Placentas from fetuses with an end-diastolic zero flow were small and thick with an extrachorial configuration, marginal cord insertion, magistral or mixed allantochorial vessel pattern and few cotyledons. The incidence and the extension of gross lesions were slightly increased in these placentas compared to placentas from fetuses with a normal S/D ratio (peak systolic velocity/minimum diastolic velocity). Placentas from fetuses with an increased S/D ratio (greater than +2SD) were large and thin with a high maximum diameter/maximum thickness ratio. Heavily smoking mothers were overrepresented in the group, with an increased S/D ratio and corresponding SGA infants. End-diastolic zero flow in the umbilical artery was strongly correlated with placental developmental abnormalities.

Clinical symptoms after anal sphincter rupture: a retrospective study.

Background. To evaluate the current anal sphincter function, the frequency of urinary incontinence and of dyspareunia in patients with earlier anal sphincter rupture following vaginal delivery.

The effect of bedrest in hospital on fetal outcome in pregnancies complicated by intra-uterine growth retardation

A prospective study was made to evaluate whether bedrest in hospital is beneficial in pregnancies where intrauterine growth retardation (IUGR) was suspected. Diagnosis was based on routine fetometry at 32 weeks of gestation, in conjunction with general ultrasound screening. 107 patients with suspected IUGR‐pregnancies were divided into two groups, 49 in a hospital bedrest group and 58 in an ‘outpatient’ group. Fifteen women in the bedrest group refused hospitalization, and 8 women in the out‐patient group had to be hospitilised for medical reasons other than suspected growth retardation, leaving 79% of the women in their allocated group. The women in the bedrest group were hospitalized for a mean duration of 29.2 days (range 5‐54). The results suggest that bedrest in hospital is not beneficial, either to fetal growth or to pregnancy outcome.

ULTRASOUND SCREENING FOR DETECTION OF INTRA-UTERINE GROWTH RETARDATION

Intra‐uterine growth retardation (IUGR) is a major problem in contemporary obstetrics. Early antenatal diagnosis is important if morbidity and mortality are to be minimized. We present the results of one years ultrasound fetometric screening for IUGR of the pregnant population in the city of MalmO. All pregnancies were dated by early bi‐parietal diameter (BPD) measurement. From findings at 32 weeks of gestation, an IUGR risk‐group (n =436) was selected on the basis of predicted birthweight deviations with reference to standard curves, established at the Department, for BPD, abdominal diameter, femur length, and intra‐uterine weight, all plotted against gestational age. The risk‐group, which included 60 (77%) of the 78 IUGR infants eventually born, was subjected to additional fetometry examinations at 34, 36 and 38 weeks of gestation, in the total pregnant population of 2068, each pregnancy was the subject of 2.3 examinations. Other fetometry variables were evaluated for their efficacy as IUGR markers, but were not found to be superior to the current screening procedure in which BPD and abdominal diameter are combined in a simple formula to assess intra‐uterine growth. Overall, the screening procedure currently used at Malmd had a sensitivity of 64.1% and a specificity of 96.5%, the prevalence for IUGR being 3.8%.

Perinatal Outcome in Growth Retarded Pregnancies Dated by Ultrasound

To analyse the incidence of fetal growth retardation and its impact on perinatal mortality and neonatal morbidity, pregnancies complicated by intra‐uterine growth retardation (IUGR) were compared with matched non‐IUGR pregnancies. The IUGR group included all infants born in the city of Malmö during the study period and having a birthweight of 2 standard deviations or more below the mean birthweight for gestational age. The gestational age of all pregnancies was assessed with ultrasound in the first half of pregnancy. The IUGR fetuses were more vulnerable during delivery, and emergency cesarean section due to imminent fetal asphyxia was performed more frequently, but Apgar scores were similar in both groups. The frequency of respiratory disorders was lower in the IUGR group than in the non‐IUGR group when corticosteroid‐treated pregnancies were excluded. The IUGR group required slightly longer care on the neonatal ward than the non‐IUGR group, but not more intervention. The IUGR group as a whole had an unexpectedly low neonatal complication rate, such complications as did occur being related to preterm birth rather than to growth retardation.

The efficacy of biochemical assays in assessing an IUGR risk-group, preselected with ultrasound fetometry

Dehydroepiandrosterone sulphate, progesterone, estradiol, estriol and human placental lactogen (hPL) were biochemically assayed in a group of 92 pregnancies in which intra-uterine growth retardation was suspected. The group was selected with ultrasound fetometry at 32 weeks of gestation, and maternal blood was sampled at 33, 35, 37 and 39 weeks of gestation. The IUGR group consisted of 30 pregnancies resulting in the birth of an infant with a birthweight of 2 standard deviations or more below the mean for gestational age in the Malmö population. Intra-uterine growth trends were defined by serial ultrasound fetometry performed every second week. Both serum hormone and hPL content were examined in relation to birth-weight, occurrence of imminent asphyxia at delivery, Apgar score, and pH in the umbilical vein. Neither dehydroepiandrosterone sulphate, nor progesterone nor estradiol values correlated to any of the outcome variables. To some extent estriol values distinguished IUGR from non-IUGR fetuses but not until the 39th gestational week, whereas hPL was effective in this respect in all weeks studied. An hPL value below 4 mg/l predicted IUGR with a sensitivity ranging from 52% to 74%, and a specificity ranging from 85% to 78%. HPL correlated well with the subsequent intra-uterine growth rate, but not with the outcome variables studied.