Maternal complications with placenta previa.

The purpose of this study is to describe the maternal complications of placenta previa. A population-based retrospective cohort study including all women delivered in the province of Nova Scotia, Canada from 1988 to 1995 was performed. Patient information was obtained from the Nova Scotia Atlee Perinatal Database and maternal complications were described for all women undergoing cesarean delivery. Prognostic factors for the risk of hysterectomy in woman with placenta previa were analyzed by multiple logistic regression. During the 8-year period, 308 cases of placenta previa were identified in 93,996 deliveries (0.33%). Maternal complications included hysterectomy [relative risk (RR) = 33.26], antepartum bleeding (RR = 9.81), intrapartum (RR = 2.48), and postpartum (RR = 1.86) hemorrhages, as well as blood transfusion (RR = 10.05), septicemia (RR = 5.55), and thrombophlebitis (RR = 4.85). Risk factors for need of hysterectomy in women with placenta previa include the presence of placenta accreta and previous cesarean delivery.

Neonatal outcomes with placenta previa.

OBJECTIVE: To identify neonatal complications associated with placenta previa. METHODS: This was a population-based, retrospective cohort study involving all singleton deliveries in Nova Scotia from 1988 to 1995. The study group consisted of all completed singleton pregnancies complicated by placenta previa; all other singleton pregnancies were considered controls. Patient information was collected from the Nova Scotia Atlee perinatal database. Neonatal complications were evaluated while controlling for potential confounders. The data were analyzed using chi2, Fisher exact test, and multiple logistic regression. RESULTS: Among 92,983 pregnancies delivered during the study period, 305 cases of placenta previa were identified (0.33%). After controlling for potential confounders, neonatal complications significantly associated with placenta previa included major congenital anomalies (odds ratio [OR] 2.48), respiratory distress syndrome (OR 4.94), and anemia (OR 2.65). The perinatal mortality rate associated with placenta previa was 2.30% (compared with 0.78% in controls) and was explained by gestational age at delivery, occurrence of congenital anomalies, and maternal age. Although there was a higher rate of preterm births in the placenta previa group (46.56% versus 7.27%), there was no difference in birth weights between groups after controlling for gestational age at delivery. CONCLUSION: Neonatal complications of placenta previa included preterm birth, congenital anomalies, respiratory distress syndrome, and anemia. There was no increased occurrence of fetal growth restriction.

Uterine artery Doppler in the investigation of pregnancies with raised maternal serum alpha-fetoprotein.

Uterine artery flow velocity waveforms (FVW) were obtained prospectively by continuous wave Doppler at 18-22 weeks gestation from 98 women with an unexplained elevation in maternal serum alpha-fetoprotein (MSAFP). A notch in either the left or right uterine artery FVW was present in 18 pregnancies of which seven resulted in perinatal death and six in the birth of very immature and/or severely growth retarded babies. Conversely, in 66 of 80 pregnancies the absence of a notch was associated with the livebirth of an infant beyond 32 weeks gestation, with a birthweight above the 5th centile. It is suggested that the presence of a notch in the uterine artery FVW is a good predictor of poor perinatal outcome.

Platelet count in normal, small, and anemic fetuses.

A reference range for fetal platelet count with gestation was established from the study of samples obtained by cordocentesis from 229 pregnancies that had prenatal diagnosis. The mean platelet count increased from 187 +/- 47 x 10(9)/L at 15 weeks to 274 +/- 47 x 10(9)/L at 40 weeks' gestation. In 113 red cell-isoimmunized pregnancies, the moderately anemic fetuses were significantly thrombocythenic, whereas the severely anemic fetuses were thrombocytopenic. In 136 small-for-gestational-age fetuses the platelet count was reduced and there were significant correlations between the magnitude of the thrombocytopenia and the degree of fetal smallness, hypoxemia, and acidemia.

Evaluation of the lemon and banana signs in one hundred thirty fetuses with open spina bifida.

The incidence and diagnostic accuracy of the lemon and cerebellar ultrasonographic markers, as well as head size and ventriculomegaly, were evaluated in a study of 1561 patients at high risk for fetal neural tube defects. In the 130 fetuses with open spina bifida there was a relationship between gestational age and the presence of each of these markers. The lemon sign was present in 98% of fetuses at less than or equal to 24 weeks' gestation but in only 13% of those at greater than 24 weeks' gestation. Cerebellar abnormalities were present in 95% of fetuses irrespective of gestation; however, the cerebellar abnormality at less than or equal to 24 weeks' gestation was predominantly the banana sign (72%) whereas at gestations greater than 24 weeks it was cerebellar "absence" (81%). Both growth retardation and cerebral ventriculomegaly significantly worsened with gestation while the head circumference remained disproportionately small throughout gestation. On the basis of these data, a new approach is proposed for the investigation of patients at high risk for fetal open spina bifida.

Mean red cell volume in normal, anemic, small, trisomic and triploid fetuses.

A reference range for fetal mean red cell volume (MCV) with gestation was established from the study of samples obtained by cordocentesis from 466 pregnancies undergoing prenatal diagnosis for non-erythrocyte abnormalities. The mean MCV decreased from 145 fl at 16 weeks to 113 fl at 36 weeks of gestation. Alterations in MCV were investigated in 154 red cell isoimmunized and 231 small for gestational age (SGA) fetuses. In red cell isoimmunization, significant macrocytosis was observed when the fetal hemoglobin concentration deficit was greater than or equal to 6 g/dl. In the chromosomally normal SGA fetuses (n = 178), the MCV was increased and the magnitude of macrocytosis was significantly associated with gestation and the degrees of fetal 'smallness' and fetal hypoxemia. However, the most severely macrocytotic SGA fetuses were those with triploidy (n = 22). In the SGA fetuses with other chromosomal defects (n = 31), the MCV was higher than the controls but lower than that of the chromosomally normal hypoxemic fetuses. It is suggested that in severe growth retardation there is developmental delay in the normal evolution from hepatic to medullary hemopoiesis and this is most marked in triploid fetuses. In contrast, in red cell isoimmunization the switch to medullary erythropoiesis is normal, but in severe anemia there is secondary recruitment of hepatic erythropoiesis.