Per-Håkan Persson

Intrauterine growth curves based on ultrasonically estimated foetal weights

Available standard intrauterine growth curves based on birthweights underestimate foetal growth in preterm period. New growth curves are presented based on data from four Scandinavian centres for 759 ultrasonically estimated foetal weights in 86 uncomplicated pregnancies. Mean weight of boys exceeded that of girls by 2‐3%. A uniform SD value of 12% of the mean weight was adopted for the standard curves as the true SD varied non‐systematically between 9.1 and 12.4%. Applied to an unselected population of 8663 singleton births, before 210 days of gestation, 32% of birthweights were classified as small‐for‐gestational age (SGA; i.e. below mean ‐2SD); the corresponding figures were 11.1% for gestational ages between 210 and 258 days, and 2.6% for ages of 259 days or longer. The new growth curves reveal better the true distribution of SGA foetuses and neonates, and are suggested for use in perinatological practice.

Reliability of Ultrasound Fetometry in Estimating Gestational Age in the Second Trimester

The reliability of ultrasound fetometry for estimating gestational age (GA) in the second trimester was evaluated, using the fetal variables: biparietal diameter (BPD), occipitofrontal diameter (OFD), mean abdominal diameter (AD), and femur length (FL), each value being taken as the mean of five measurements. of the individual variables, BPD gave the best precision, with a standard deviation (SD) from true GA of 3.2 days. Using a combination of all four variables, GA could be estimated with a SD of 2.2 days, which was not significantly better than the formula, GA = BPD × 1.2 + FL × 1.0 + 49, which gave results with a SD of 2.4 days. Equations obtained from regression analysis of the variables against true GA were tested in 44 cases where the precise date of conception was known, GA being estimated by BPD with a SD of 3.2 days, and by the combination of BPD and FL with a SD of 2.7 days; the maximum difference between GA estimated by BPD and by FL was 7 days. Using a combination of BPD and FL to estimate GA in the total population, the number of post‐term deliveries was only marginally less than when using BPD alone.

Benefits of ultrasonic screening of a pregnant population.

Abstract. The present study describes the evolution over a 5‐year period of an ultrasonic routine screening programme of a pregnant population with participation of approximately 90 % of the pregnant women. One obvious result obtained in the screening programme is the pronounced improvement of early detection of twins, the incidence now approaching 95 % with the mean gestational age for the detection being 20 (median 19) weeks. Early detection in combination with clinical measures was associated with a decrease in the incidence of twins born preterm (before week 37) from 33 % to 10 %. The perinatal mortality rate of twins fell from 6 to 0.6 % after the introduction of this programme.

A Study of Smoking and Pregnancy with Special Reference to Fetal Growth

Abstract. A prospective study of the influence of smoking on pregnancy and its outcome was made of 5272 women in an urban community during 1974/75. Approximately 90 % of the pregnant women in the population took part in the programme. Ultrasonic measurements of the fetal biparietal diameter (BPD) were made from the 18‐20th week (early in the study the first BPD measurements were obtained at 28 weeks). Growth curves of BPD were constructed for each week, separately for the smoking groups (49 %) and the non‐smoking group (51 %) by compiling 5714 BPD measurements, only women subsequently delivered between 266 and 294 days after the last menstrual period were included to avoid erroneously skewed growth profiles. The BPD increased faster during gestation in the non‐smoking group, the difference from the smoking group being significantly apparent from the 28th week onwards and positively correlated to the average number of cigarettes smoked. There was a preponderance within the non‐smoking group for marriage, and preeclampsia; and within the smoking group for abruptio placentae, pre‐term delivery, low birth‐weight, short birth‐length, small head circumference, and small‐for‐gestational‐age. The low birth‐weights were independent of maternal prepregnant weight and weight gain. Compared with data obtained in a similar study in the same community, 1963/64, the prevalence of smoking among pregnant women had increased from 44 % to 49 %. The present study demonstrates the early onset of intrauterine growth retardation in pregnancies of smoking mothers. The results suggest that the fetal growth retardation is a direct pharmacological effect on the fetus rather than an influence resulting from nutritional deprivation and points to appearent inefficiency of the programme deterring women from smoking.

Normal Range Growth Curves for Fetal Biparietal Diameter, Occipito Frontal Diameter, Mean Abdominal Diameters and Femur Length

Normal range curves for the growth of fetal biparietal diameter (BPD), occipitofrontal diameter (OFD), mean abdominal diameter (AD), and femur length (FL) were obtained in a longitudinal series of ultrasound measurements in 19 normal pregnancies. Regression analysis was used to fit the data to equations. The best equations for BPD and AD on gestational are close to similar longitudinally obtained regression curves from other Scandinavian countries.

Prediction of Fetal Growth Deviation by Ultrasonic Biometry: II. Clinical application

Abstract. A previously developed mathematical formula for prediction of fetal growth deviation at birth by means of ultrasonic fetometry was applied to 505 unselected singleton pregnancies. The gestational age was assessed by measuring the fetal biparietal diameter (BPD) in the 17th week of pregnancy. In the 33rd and 38th week of pregnancy, BPD and the abdominal diameters (AD) were measured. In detecting fetuses small‐for‐gestational age (SGA) in the 33rd week, the ultrasonic diagnostic test had a nosological sensitivity of 77% and a nosological specificity of 78%. The nosological sensitivity and specificity for detecting fetuses large‐for‐gestational age (LGA) were 75% and 82%, respectively. The result was not improved significantly when the formula was applied to the total group in the 38th week. At the 33rd week examination risk groups with high prevalence of SGA and LGA fetuses were identified. When these groups were submitted to an additional examination in the 38th week, the prevalence of SGA and LGA fetuses in the new risk groups increased to 50%. At the 33rd week examination the predictive value of a negative test for SGA and LGA was 98%. Thus, the procedure described is well suited for general screening of pregnant women with ultrasound, and, combined with other biochemical and biophysical tests, makes possible a close clinical surveillance of the fetus at risk.

Normal Range Curves for the Intrauterine Growth of the Biparietal Diameter

Abstract. Normal range curves for the growth of the fetal biparietal diameter (BPD) measured by ultrasound were calculated in three different ways; I. 93 selected women examined longitudinally with three‐week intervals from the 16th gestational week to term. II. Measurements for each week compiled with only the first measurement from each patient. From the 20th to the 30th week, 3,243 BPD determinations obtained in a routine screening programme was used. III. 157 BPD measurements from 60 women with known date of ovulation.

Thyroid Gland Volume as Measured by Ultrasonography in Healthy Children and Adolescents in a Non‐Iodine Deficient Area

We performed this study to determine the normal thyroid gland size in children of various ages living in Malmo, which is an iodine-sufficient area of Sweden

Prediction of fetal growth deviation by ultrasonic biometry: I. Methodology

Abstract. Early information of impaired or accelerated fetal growth is of importance for antenatal care. The present study has produced a mathematical formula which in the 33rd week of pregnancy permits prediction of fetal weight deviation at birth. The prediction was based on two ultrasonic examinations: in the 17th week of pregnancy the biparietal diameter (BPD) was measured to assess the fetal gestational age; in the 33rd week of pregnancy, BPD and the abdominal diameter (AD) of the fetus were measured. Fetal growth deviation was then described by comparing the assessed BPD and AD with the expected mean values for the gestational age on the day of this measurement. For 872 fetuses the growth deviation found in the 33rd week was related to the fetal weight deviation at birth; multiple regression analyses were performed and a mathematical formula developed. For practical purposes this formula is expressed in a nomogram.

Filled bladder simplifies human embryo transfer

Collection of pre-ovulatory oocytes for fertilization in vitro is now considered a quite straightforward procedure, especially in stimulated women and when using a teflon-coated aspiration needle. Moreover, cleavage of oocytes after fertilization in vitro has reached a high figure (Leeton et al. 1982). However, difficulties encountered in embryo transfer are not uncommon (Edwards et al. 1980; Leeton et al. 1982). Various technical procedures have been tried to facilitate the passage of the transfer catheter through the cervical canal into the uterine cavity. These techniques include placing the patient in different positions (Leeton et al. 1982; Jones et al. 1982), an outer cannula in the cervical canal (Leeton et al. 1982), dilatation of the cervical canal (Lopata et al. 1980), and the use of a tenaculum on the anterior lip of the cervix (Leeton et a]. 1982). Moreover, sedation of the patient has been used (Leeton et al. 1982), as some of these techniques can be uncomfortable for the patient and the procedure is occasionally protracted, while some can be unnecessarily traumatic. A simple technique is described for easy passage of the catheter into the uterine cavity in women who have an anteverted uterus. It is the angle between the cervical-uterine canal and the vagina (speculum exposed) that often makes it difficult for the transfer catheter to pass smoothly into the uterine cavity. A filled bladder will tilt the uterus to an upright position in line with the vagina (speculum exposed) (Figs 1 & 2). The woman is therefore asked to drink 1 litre of water 1 h before embryo transfer (as for an ultrasound examination). If ultrasound is used, the catheter can be seen entering the uterine cavity. Otherwise, ultrasound examination before embryo transfer is useful, to measure the exact length from the external 0 s to the fundus for controlled deposition of a transferred embryo (Leeton et al. 1982). In 14 consecutive embryo transfers, the filledbladder method was used. The woman was placed in a slight Trendelenburg position and the cervix was exposed with a bivalve speculum. An intrauterine device inserter was gently introduced 0.5-1.0 cm into the cervical canal to guide the