Estriol in pregnancy

Sex, Gender, and Sex Hormones in Pulmonary Hypertension and Right Ventricular Failure

Pulmonary hypertension (PH) encompasses a syndrome of diseases that are characterized by elevated pulmonary artery pressure and pulmonary vascular remodeling and that frequently lead to right ventricular (RV) failure and death. Several types of PH exhibit sexually dimorphic features in disease penetrance, presentation, and progression. Most sexually dimorphic features in PH have been described in pulmonary arterial hypertension (PAH), a devastating and progressive pulmonary vasculopathy with a 3-year survival rate <60%. While patient registries show that women are more susceptible to development of PAH, female PAH patients display better RV function and increased survival compared to their male counterparts, a phenomenon referred to as the "estrogen paradox" or "estrogen puzzle" of PAH. Recent advances in the field have demonstrated that multiple sex hormones, receptors, and metabolites play a role in the estrogen puzzle and that the effects of hormone signaling may be time and compartment specific. While the underlying physiological mechanisms are complex, unraveling the estrogen puzzle may reveal novel therapeutic strategies to treat and reverse the effects of PAH/PH. In this article, we (i) review PH classification and pathophysiology; (ii) discuss sex/gender differences observed in patients and animal models; (iii) review sex hormone synthesis and metabolism; (iv) review in detail the scientific literature of sex hormone signaling in PAH/PH, particularly estrogen-, testosterone-, progesterone-, and dehydroepiandrosterone (DHEA)-mediated effects in the pulmonary vasculature and RV; (v) discuss hormone-independent variables contributing to sexually dimorphic disease presentation; and (vi) identify knowledge gaps and pathways forward. © 2020 American Physiological Society. Compr Physiol 10:125-170, 2020.

The significance of abnormal glucose tolerance (hyperglycaemia and hypoglycaemia) in pregnancy

Maternal hypoglycaemia (plasma glucose below 5th centile) had a highly significant association with fetal growth retardation, and perinatal mortality was significantly increased in the presence of both hypoglycaemia and hyperglycaemia (plasma glucose above 95th centile) when pregnancy outcome was analyzed in 5000 consecutive patients who had a glucose tolerance test performed during the third trimester of pregnancy. This study confirms the significance of abnormal glucose tolerance as a causative factor of feto-placental dysfunction. The flat glucose tolerance test pattern had no significance beyond the presence of associated hypoglycaemia, but reactive hypoglycaemia, and persistent abnormalities of plasma glucose levels during the test, were associated with higher incidences of complicated outcome. Hypertonic dextrose therapy administered to the patient with persistently subnormal urinary oestriol excretion was less likely to cause a favourable response in oestriol excretion if glucose tolerance was abnormal, perhaps because the adverse influences of abnormal glucose tolerance were not reversible by the third trimester of pregnancy. Hypoglycaemia and hyperglycaemia, additional to diabetes mellitus, are significant factors in the aetiology and diagnosis of abnormal pregnancy, and point to the need to investigate therapeutic measures.

Rapid determination of urine estriol by an on-column derivatization procedure

Estriol in pregnancy urine is determined by acid hydrolysis of steroid conjugates, followed by ether and aqueous sodium hydroxide extraction and gas chromatography. Derivatives are formed within the injection port of the gas chromatograph using tetramethylammonium hydroxide. Several samples may be processed simultaneously. Hydrolysis and extraction of a specimen are done in a single culture tube; for larger numbers of specimens, a Paton-Brown extractor may be used. With a two-column gas chromatograph, results on two specimens are available within one hour; twelve analyses may be completed within two hours.

The influence of abnormal glucose tolerance (hyperglycaemia and hypoglycaemia) on pregnancy outcome when oestriol excretion is subnormal

Subnormal urinary oestriol excretion was present in 611 (13.9 per cent) of 4403 consecutive patients in whom a glucose tolerance test had been performed and urinary oestriol excretion measured during the third trimester of pregnancy. Hypoglycaemia (less than 5th centile) had a significant association with subnormal oestriol excretion. The perinatal mortality rate was significantly higher in the presence of abnormal glucose tolerance when oestriol excretion was low. Normoglycaemia was associated with a perinatal mortality rate of 1.7 per cent when oestriol excretion was persistently low, whereas in the presence of hyperglycaemia (greater than 95th centile) the perinatal mortality rate was 12.5 per cent (P less than 0.01) and when there was hypoglycaemia the rate was 14.8 per cent (P less than 0.001). Small-fordates babies occurred in 46.3 per cent of pregnancies complicated by hypoglycaemia and persistently subnormal urinary oestriol excretion. The advantage of routine urinary oestriol assay and glucose tolerance testing in pregnancy is emphasized.

Placental insufficiency in relation to postterm pregnancy and fetal postmaturity. Evaluation of fetoplacental function; management of the postterm gravida

As pregnancy extends post term, incidence of placental insufficiency, fetal postmaturity (dysmaturity), and fetal perinatal death increases rapidly as a consequence of reduced respiratory and nutritive placental function. Despite a compensatory fetoplacental respiratory reserve capacity, fetal distress is observed in about one third of postterm pregnancies. On a biochemical level, placental pathophysiology in postterm-postmaturity pregnancies is not well understood. Postmaturity is correlated with increased incidence of placental lesions, fetal hypoxia-asphyxia, intrauterine growth retardation, increased perinatal death, and neonatal morbidity. Early diagnosis of fetal postmaturity is difficult because currently applied test methods allow recognition only when placental insufficiency is far progressed. Therefore, in postterm gravidas with a favorable cervix, induction of labor should be considered; in older primigravidas, in whom fetal losses may be sevenfold increased, or in multiparas with a history of obstetric complications, pregnancy may require termination by cesarean section. Pregnancy may be allowed to continue under close supervision in cases of uncertainty of duration of gestation, in gravidas carrying small babies, in young primigravidas, and in multigravidas in whom placentofetal function tests are normal. As long as fetal scalp blood sampling during labor does not show fetal acidosis, despite abnormal fetal heart rate pattern and meconium release, vaginal delivery may be attempted when deemed possible within a few hours. In parturients attention must be paid to the extent of uterine activity and type of medication; lateral positioning of the gravida and maternal oxygen breathing, facilitating fetal oxygen supply, are important features. Because during bearing-down efforts placentofetal respiratory reserves of postterm gravidas may become further compromised, immediate delivery by forceps or vacuum extraction may be considered. After delivery the umbilical cord should not be clamped immediately in order to allow increased fetal blood supply and to counteract fetal hypovolemia. Dysmature newborn infants require special care by the neonatologist.