Biomedical subjects

H Rydhstroem

Publications and source records attributed to H Rydhstroem.

23 records · Page 2Linked to original sources

PubMed1997

Association of blood loss during delivery to B-hemoglobin.

OBJECTIVE: To study the association between blood loss during delivery and B-hemoglobin before and after delivery (3 days and 10 weeks, respectively). MATERIALS AND METHODS: Information on blood loss for 693 women, 93.9% of all parturients during the study period, was extracted from the original medical records. B-hemoglobin was analyzed at the antenatal maternal health care unit at the last visit before delivery, in capillary samples taken on the ward on the 3rd day, or 10 weeks after delivery. Associations were estimated with Pearson's parametric correlation coefficient. RESULTS: Altogether, 31.3% of all parturients had a higher B-hemoglobin value on the 3rd day after delivery than on the last visit to the maternal health care unit before delivery; the mean intrapartum blood loss was 375 ml (range 100-2,200 ml). The correlation coefficient between B-hemoglobin on the 3rd day after delivery and blood loss was r = -0.53. When the last value recorded at the antenatal maternal health care unit was included in the analysis, the correlation coefficient remained virtually unchanged (r = -0.52). Only 14 (blood loss < or = 600 ml), or 11% (blood loss >600 ml) of the variation in the B-hemoglobin was accounted for by the amount of blood loss. No significant correlation coefficient was evident for B-hemoglobin 10 weeks after delivery vis-à-vis blood loss, irrespective of whether iron supplementation was administered (r = 0.01) or not (r = 0.17). CONCLUSION: The weak association between intrapartum blood loss and B-hemoglobin suggests that the value of B-hemoglobin determined after delivery may be less indicative than previously thought. This conclusion is strengthened by the fact that only a minor part (< or = 14%) of the variation in B-hemoglobin on the 3rd day after delivery is explained by the amount of blood lost.

Biomarkers↗

PubMed1996

The effect of maternal smoking on birth weight in twin pregnancies.

Information on 869 076 singletons and 17 566 twins, born during the period 1983-1991, was obtained from the Swedish Medical Birth Registry. Data on birth weight, gestational duration, vital status, and maternal smoking habits during pregnancy were analyzed in order to investigate whether twinning potentiates the effect of maternal smoking on birth weight and perinatal mortality. The individual birth weights were expressed as percentages of mean birth weight, where mean birth weights of singletons and twins were calculated separately. The birth weight reducing effect of maternal smoking was found to be of the same magnitude among twins and singletons weighing > 90% of mean birth weight. For infants weighing < 90% of mean birth weight, maternal smoking had a significantly stronger effect on birth weight among singletons than among twins. When gestational duration was taken into consideration, this difference was less pronounced. The effect of maternal smoking on gestational duration was stronger among singletons than twins. The smoking-related risk increase of perinatal death was of about the same magnitude among twins and singletons.

Birth Weight↗

PubMed1996

Pregnancy with stillbirth of both twins.

OBJECTIVE: To identify and evaluate clinical characteristics in pregnancy leading to stillbirth of both twins. MATERIAL AND METHODS: All 68 twin deliveries in Sweden from 1973 to 1989 inclusive, where both twins were dead at birth, were identified by extracting information filed at the Medical Birth Registry (MBR), the National Board of Health and Welfare, Stockholm. Information in the MBR was used for analysis. A questionnaire was also distributed to each delivery unit to obtain information on ultrasound scan made before either or both twins died, and type of placentation. RESULTS: The relative risk for like-sexed (n=66) vis-a-vis unlike-sexed fetuses (n=2) to suffer intrauterine death was 12.6 (95% confidence limits 4.3, 37.5). The rate of like-sexed twins was 97.1% versus 72.2% for the general twin population; monochorionic placentation was identified in 50.0% of these pregnancies. In only seven was there a cause of death evident, including five pregnancies with lethal malformation. The median gestational duration was 33 weeks (range 26 to 41). For the smaller twin in the pair there was an obvious trend toward low birthweight and 16.l% were by definition small for gestational age, whereas the larger twins seemed to have a normal birthweight distribution. The proportion of pregnancies with both twins stillborn increased significantly with increasing discordance in weight (linear trend X2=4.5; P=0.03). The interval between ultrasound examination showing two living fetuses and delivery was nine days or less in half the cases. CONCLUSION: The major risk factor for fetal deaths seems to be a like-sexed pregnancy with a monochorionic placenta. About half of pregnancies with available information had no more than nine days between an ultrasound examination, confirming two living fetuses, and birth. The great majority of these twins did not show evidence of growth retardation, but birthweight discordance may be a risk factor for fetal deaths.

Birth Weight↗

PubMed1996

Lack of correlation between maternal body weight or weight gain and stillbirth in twin pregnancy.

OBJECTIVE: To study differences in maternal weight and weight gain for 48 twin-pregnant women with at least one stillbirth, versus 96 control mothers where both twin pairs survived the perinatal period. MATERIAL AND METHODS: In all, 48 twin gestations with one or both twins dead before or during birth (cases), in a defined region with 12 hospitals in southern Sweden between 1973 and 1989, were identified by using information stored at the Medical Birth Registry, the National Board of Health and Welfare, Stockholm. For each case pregnancy, two control twin pregnancies were selected; matching criteria were same parity and delivery unit, and similar year of delivery (+/- 1 year) and maternal age (+/- 5 years). RESULTS: Case and control women had a similar number of maternal body weight measurements during pregnancy, 8.9 vs. 8.0 (t = 1.5, p > 0.05). No significant difference between cases and controls was found regarding maternal weight (mean +/- SEM) at 12 weeks of gestation (68.0 +/- 1.4 vs. 68.1 +/- 0.9 kg; t = 0.2, p > 0.05), or in weight gain/pregnancy week (0.59 +/- 0.28 vs. 0.61 +/- 0.19 kg; t = 0.8; p > 0.05). CONCLUSION: The results of this study indicate that repeated body weight measurements of the twin-pregnant woman are of very limited value in the identification of a twin-pregnant woman later to face stillbirth.

Body Weight↗

PubMed1995

The relationship of birth weight and birth weight discordance to cerebral palsy or mental retardation later in life for twins weighing less than 2500 grams.

OBJECTIVE: This study tested the hypothesis that twins with a birth weight < 2500 gm who subsequently had cerebral palsy or mental retardation had a birth weight distribution or birth weight discordance distribution differing from that of the total live-born twin population also weighing < 2500 gm at birth. STUDY DESIGN: All twins born in Sweden between 1973 and 1980 (n = 5382) and having a birth weight < 2500 gm were identified by using information stored at the Medical Birth Registry, the National Board of Health and Welfare, Stockholm, or at Statistics Sweden. To identify twins with cerebral palsy or mental retardation, a questionnaire bearing the personal identification number (given to all newborns in Sweden shortly after birth) was distributed to all rehabilitation centers, all county school boards, all local boards of education, and to all County Councils for the Provisions and Services for the Mentally Retarded. The questionnaire was distributed in 1988 and 1989 when the twins were > or = 8 years old. RESULTS: Altogether 115 disabled twins resulting from 99 pregnancies were identified. The incidence of disabled twins per 1000 was 21.4 (95% confidence interval 17.5 to 25.2). No obvious difference was evident in the distribution of birth weight discordance when the twins with disability were compared with the population of all live-born twins having a birth weight < 2500 gm. Disabled twins had a significantly lower birth weight for gestational age (t = -3.5, p < 0.001), but in fact only 10 (8.7%) twins had a birth weight < -2 SD. No difference in the incidence of disability was found for twin A versus twin B (relative risk 1.3, 95% confidence interval 0.8 to 1.9) or for like-sex versus unlike-sex twins (relative risk 1.0, 95% confidence interval 0.6 to 1.6). However, the larger twin in the pair had a significantly higher incidence of cerebral palsy than the smaller one did (relative risk 2.6, 95% confidence interval 1.4 to 4.8). CONCLUSIONS: Birth weight discordance for twins seems not to be related to disability later in life. The great majority of twins with a birth weight < 2500 gm who later became disabled were appropriate for gestational age at birth.

Birth Weight↗