Abruptio placentae

Poor Vitamin C Status Late in Pregnancy Is Associated with Increased Risk of Complications in Type 1 Diabetic Women: A Cross-Sectional Study

Vitamin C (vitC) is essential for normal pregnancy and fetal development and poor vitC status has been related to complications of pregnancy. We have previously shown lower vitC status in diabetic women throughout pregnancy compared to that of non-diabetic controls. Here, we evaluate the relationship between vitC status late in diabetic pregnancy in relation to fetal outcome, complications of pregnancy, diabetic characteristics, and glycemic control based on data of 47 women from the same cohort. We found a significant relationship between the maternal vitC level > or ≤ the 50% percentile of 26.6 μmol/L, respectively, and the umbilical cord blood vitC level (mean (SD)): 101.0 μmol/L (16.6) versus 78.5 μmol/L (27.8), p = 0.02; n = 12/16), while no relation to birth weight or Apgar score was observed. Diabetic women with complications of pregnancy had significantly lower vitC levels compared to the women without complications (mean (SD): 24.2 μmol/L (10.6) vs. 34.6 μmol/L (14.4), p = 0.01; n = 19 and 28, respectively) and the subgroup of women (about 28%) characterized by hypovitaminosis C (<23 μmol/L) had an increased relative risk of complications of pregnancy that was 2.4 fold higher than the one found in the group of women with a vitC status above this level (p = 0.02, 95% confidence interval 1.2-4.4). No correlation between diabetic characteristics of the pregnant women and vitC status was observed, while a negative association of maternal vitC with HbA1c at delivery was found at regression analysis (r = -0.39, p < 0.01, n = 46). In conclusion, our results may suggest that hypovitaminosis C in diabetic women is associated with increased risk of complications of pregnancy.

Extra and intracellular calcium signaling pathway(s) differentially regulate histamine-induced myometrial contractions during early and mid-pregnancy stages in buffaloes (Bubalus bubalis)

This study examines the differential role of calcium signaling pathway(s) in histamine-induced uterotonic action during early and mid-pregnancy stages in buffaloes. Compared to mid pregnancy, tonic contraction, amplitude and mean-integral tension were significantly increased by histamine to produce myometrial contraction during early pregnancy with small effects on phasic contraction and frequency. Although uterotonic action of histamine during both stages of pregnancy is sensitive to nifedipine (a L-type Ca²⁺ channels blocker) and NNC55-0396 (T-type Ca²⁺ channels blocker), the role of extracellular calcium seems to be more significant during mid-pregnancy as in this stage histamine produced only 9.38±0.96% contraction in Ca²⁺ free-RLS compared to 21.60±1.45% in uteri of early pregnancy stage. Intracellular calcium plays major role in histamine-induced myometrial contraction during early pregnancy as compared to mid pregnancy, as in the presence of cyclopiazonic acid (CPA) Ca²⁺-free RLS, histamine produced significantly higher contraction in myometrial strips of early-pregancy in comparison to mid-pregnancy (10.59±1.58% and 3.13±0.46%, respectively). In the presence of U-73122, the DRC of histamine was significantly shifted towards right with decrease in maximal effect (E_max) only in early pregnancy suggesting the predominant role of phospholipase-C (PL-C) in this stage of pregnancy.

Supplementation with vitamins C and E during pregnancy for the prevention of preeclampsia and other adverse maternal and perinatal outcomes: a systematic review and metaanalysis

OBJECTIVE

To determine whether supplementation with vitamins C and E during pregnancy reduces the risk of preeclampsia and other adverse maternal and perinatal outcomes.

STUDY DESIGN

Systematic review and metaanalysis of randomized controlled trials.

RESULTS

Nine trials involving a total of 19,810 women were included. Overall, there were no significant differences between the vitamin and placebo groups in the risk of preeclampsia (9.6% vs 9.6%; relative risk, 1.00, 95% confidence interval, 0.92-1.09). Similar results were obtained when subgroup analyses were restricted to women at high risk or low/moderate risk for preeclampsia. Women supplemented with vitamins C and E were at increased risk of developing gestational hypertension and premature rupture of membranes, and decreased risk of abruptio placentae. There were no significant differences between the vitamin and placebo groups in the risk of other adverse maternal or fetal/perinatal outcomes.

CONCLUSION

Supplementation with vitamins C and E during pregnancy does not prevent preeclampsia.

Pre-eclampsia, placental abruption and increased risk of atopic sensitization in male adolescent offspring

PROBLEM

The aim of this study was to investigate maternal pre-eclampsia (PE), placental abruption (PA) and atopy among offspring.

METHOD OF STUDY

Obstetric data was recorded from 378 women who were included into the Caesarean delivery birth cohort during 1990-1992. When their children were 15-17 years old skin prick tests (SPTs) and inhalant allergen-specific (IAS) immunoglobulin E (IgE) were determined among offspring.

RESULTS

Adolescents whose mothers had either PE or PA at the time of delivery had more atopy and especially more severe atopy as measured by the incidence of SPTs positive for > or = 5 allergens (RR: 4.28, 95% CI: 1.54-11.92; P < 0.005) and elevated IAS IgE levels (> or = 1.0 kU/L) (RR: 4.27, 95% CI: 1.08-16.99; P < 0.039). This increased risk was particularly observed in male adolescents.

CONCLUSION

Maternal PE and PA were associated with an increased risk of severe atopy, especially in male adolescent offspring.

Selective regulation of H1 histamine receptor signaling by G protein-coupled receptor kinase 2 in uterine smooth muscle cells

Histamine stimulates uterine contraction; however, little is known regarding the mechanism or regulation of uterine histamine receptor signaling. Here we investigated the regulation of Galpha(q/11)-coupled histamine receptor signaling in human myometrial smooth muscle cells using the inositol 1,4,5-trisphosphate biosensor pleckstrin homology domain of phospholipase-delta1 tagged to enhanced green fluorescent protein and the Ca(2+)-sensitive dye Fluo-4. Histamine addition caused concentration-dependent increases in inositol 1,4,5-trisphosphate and [Ca(2+)](i) in the ULTR human uterine smooth muscle cell line and primary human myometrial cells. These effects were completely inhibited by the H(1) histamine receptor antagonist, diphenhydramine, and were unaffected by the H(2) histamine receptor antagonist, cimetidine. ULTR and primary myometrial cells were transfected with either dominant-negative G protein-coupled receptor kinases (GRKs) or small interfering RNAs targeting specific GRKs to assess the roles of this protein kinase family in H(1) histamine receptor desensitization. Dominant-negative GRK2, but not GRK5 or GRK6, prevented H(1) histamine receptor desensitization. Similarly, transfection with short interfering RNAs (that each caused >70% depletion of the targeted GRK) for GRK2, but not GRK3 or GRK6, also prevented H(1) histamine receptor desensitization. Our data suggest that histamine stimulates phospholipase C-signaling in myometrial smooth muscle cells through H(1) histamine receptors and that GRK2 recruitment is a key mechanism in the regulation of H(1) histamine receptor signaling in human uterine smooth muscle. These data provide insights into the in situ regulation of this receptor subtype and may inform pathophysiological functioning in preterm labor and other conditions involving uterine smooth muscle dysregulation.

Effects of histamine and diamine oxidase activities on pregnancy: a critical review

BACKGROUND

Histamine has been assumed to contribute to embryo-uterine interactions due to its vasoactive, differentiation and growth-promoting properties. However, its exact functions in pregnancy are unclear. The histamine-degrading enzyme diamine oxidase (DAO) is produced in high amounts by the placenta and has been supposed to act as a metabolic barrier to prevent excessive entry of bioactive histamine from the placenta into the maternal or fetal circulation.

METHODS

The literature available on PubMed published in English between 1910 and 2008 has been searched using the isolated and combined key words histamine, diamine oxidase, pregnancy, placenta, endometrium, miscarriage, implantation, pre-eclampsia, intrauterine growth retardation, diabetes and embryonic histamine-releasing factor (EHRF).

RESULTS

High expression of the histamine-producing enzyme histidine decarboxylase in the placenta, histamine receptors at the feto-maternal interface and the existence of an EHRF suggest a physiological role of histamine during gestation. The balance between histamine and DAO seems to be crucial for an uncomplicated course of pregnancy. Reduced DAO activities have been found in multiple heterogeneous complications of pregnancy such as diabetes, threatened and missed abortion and trophoblastic disorders. Whether women with histamine intolerance suffer from more complicated pregnancies and higher abortion rates due to impaired DAO activities and if low DAO levels or genetic modifications in the DAO gene might therefore represent a prognostic factor for a higher risk of abortion, has not been investigated yet.

CONCLUSIONS

Low activities of the histamine-degrading enzyme DAO might indicate high-risk pregnancies, although high intra- and interindividual variations limit its value as a screening tool.

The links between maternal histamine levels and complications of human pregnancy

Previous literature published since 1910 on maternal blood histamine levels and complications of pregnancy have been reviewed, showing links between hyper-histaminemia occurring in specific gestational complications including preeclampsia, spontaneous abortion, preterm labour and hyperemesis gravidarum. These complications may present with symptoms similar to those of experimentally induced high blood histamine or hyper-histaminemia in non-pregnant humans. Maternal levels of histamine in normal pregnancy decrease below values found in healthy non-pregnant women. However, in some complications of pregnancy, maternal blood histamine levels rise above those associated with normal pregnancy and may exceed normal non-pregnant circulating levels. These links between circulating maternal histamine levels and specific complications of human pregnancy suggest that further investigations to evaluate the outcome of managing maternal blood histamine levels during such complications may be warranted.

Nutrition in pregnancy: mineral and vitamin supplements

Pregnancy is associated with physiologic changes that result in increased plasma volume and red blood cells and decreased concentrations of circulating nutrient-binding proteins and micronutrients. In many developing countries, these physiologic changes can be aggravated by undernutrition, leading to micronutrient deficiency states, such as anemia, that can have disastrous consequences for both mothers and newborn infants. Multiple micronutrients are often taken by pregnant women in developed countries, but their benefits are limited, except for prophylactic folic acid taken during the periconceptional period. Women in developing countries may benefit from multiple-micronutrient prophylaxis in pregnancy, but the underlying basis and rationale for changing from supplementation with iron and folate to supplementation with multiple micronutrients has not been debated in the context of existing program objectives. There is an urgent need for this discussion so that both program effectiveness and program efficacy can be improved.