Folate, vitamin B12, and homocysteine levels in South Asian women with growth-retarded fetuses

OBJECTIVE. To investigate whether intrauterine growth retardation (IUGR) and preterm delivery in a poor population of South Asia was associated with altered maternal and fetal levels of folate, vitamin B12, and homocysteine. SUBJECTS AND METHODS. Hundred and twenty-eight pregnant women from a low socio-economic strata in the city of Lahore, Pakistan were followed with ultrasound of fetal growth from the 12th week of pregnancy. Blood samples were drawn from the woman and the cord at delivery. Serum was analyzed by a chemiluminescent immunoassay for folate and vitamin B12 and by fluorescence polarization immunoassay for total homocysteine (tHcy). RESULTS. Fourty-six infants showed IUGR. In term, but not preterm, deliveries with IUGR, maternal and cord blood folate levels were half of those in deliveries of normal birth weight infants (P=0.004 and P=0.005). The risk of IUGR was reduced among women with folate levels in the highest quartile (OR 0.31, 95% CI 0.10--0.84). There was no association between vitamin B12 and IUGR. Total homocysteine levels were higher in women delivering IUGR infants (P=0.02). There was an inverse correlation between cord blood folate and tHcy levels (r=-0.26, P=0.006). We also found increased risks for hypertensive illness (OR 3.5, 95% CI 1.4--8.6) and premature delivery (OR 2.5, 95% CI 1.1--6.2) in women in the highest quartile of tHcy. CONCLUSIONS. The occurrence of IUGR increased with low maternal and cord concentrations of folate and high maternal levels of tHcy. Further studies on the effects of vitamin B supplementation through pregnancy are warranted.     

Biologically active corticotropin-releasing hormone in maternal and fetal plasma during pregnancy

Corticotropin-releasing hormone was measured in the plasma of 110 pregnant women and in the umbilical cord plasma of 25 premature infants and 43 infants born at term. Mean maternal plasma corticotropin-releasing hormone was undetectable (less than 41 pg/ml) until mid-second trimester, rose to a mean of 204 +/- 24 pg/ml by 30 weeks' gestation, to 326 +/- 41 by 35 weeks, and then rose sharply near term, with a mean of 2930 pg/ml at 38 to 40 weeks' gestation. Sequential measurements in seven pregnant women confirmed that plasma corticotropin-releasing hormone rose in a predictable pattern, with a dramatic increase in the final weeks of pregnancy. There was little hour-to-hour variability in maternal plasma concentrations. Corticotropin-releasing hormone was also detectable in umbilical cord plasma; mean corticotropin-releasing hormone was 194 +/- 44 in the preterm infants and 150 +/- 19 in the term infants. The corticotropin-releasing hormone extracted from both the maternal and fetal circulation was biologically active in vitro and caused the dose-dependent release of adrenocorticotropic hormone and beta-endorphin from cultured rat anterior pituitary cells. A significant correlation was found between maternal plasma corticotropin-releasing hormone and cortisol levels the morning after betamethasone administration, a finding that supports a physiologic role for maternal plasma corticotropin-releasing hormone. We conclude that the placenta secretes large amounts of biologically active corticotropin-releasing hormone into both the maternal and fetal circulation during pregnancy. We demonstrate that this corticotropin-releasing hormone is secreted into the maternal plasma in a reproducible pattern during normal term pregnancy and suggest that sequential corticotropin-releasing hormone measurements may prove to be of clinical utility. In addition, placental corticotropin-releasing hormone may be an important modulator of the hypothalamic-pituitary-adrenal axis during pregnancy.     

The effect of labor on maternal and fetal vitamins C and E

OBJECTIVE: This study was conducted to compare maternal and fetal plasma, amniotic fluid, and chorioamnion levels of vitamins C and E in term (>38 weeks' gestation) subjects undergoing elective repeat cesarean section (CS) without labor with values of subjects of similar gestational age and dietary intake undergoing labor and vaginal delivery (VD). STUDY DESIGN: Healthy women undergoing elective repeat CS (n = 5) or uncomplicated VD (n = 5) at term (>38 weeks' gestation) were studied. For CS patients, maternal and fetal (cord) blood, amniotic fluid, and chorioamnion samples were collected at time of surgery. For VD patients, maternal blood and amniotic fluid were obtained at 5 cm cervical dilation and fetal cord blood and chorioamnion were collected at delivery. Each patient completed a nutritional questionnaire. Plasma and membrane vitamin E concentrations were determined by reversed-phase high-performance liquid chromatography and standardized to cholesterol or membrane protein, respectively. Vitamin C was determined with the use of the 2,4-DNPH method. RESULTS: Dietary intakes for vitamins C and E as well as maternal and fetal vitamin E plasma concentrations were similar for CS and VD patients. In both groups, maternal levels were higher than fetal levels(P <.05). Chorioamnion membrane vitamin E measurements in both groups were similar. Vitamin C concentrations in CS and VD patients were highest in amniotic fluid, lower in fetal plasma, and lowest in maternal plasma. However, mean vitamin C concentrations in maternal plasma, amniotic fluid, and fetal plasma of VD patients were significantly lower, being only 20% +/- 6%, 29% +/- 11%, and 22% +/- 2% of values obtained from CS patients. CONCLUSION: During labor in healthy women at term, uterine contractile activity may generate reactive oxygen species (ROS) through the process of repetitive ischemia and reperfusion. With the significant depletion of vitamin C during labor, we speculate that water-soluble vitamin C scavenges ROS in the aqueous phase and recycles lipid-soluble vitamin E to combat ROS-induced tissue damage.     

Effects of maternal antioxidant supplementation on maternal and fetal antioxidant levels: a randomized, double-blind study

OBJECTIVE: We sought to determine whether vitamins C and E could be delivered to the fetal-placental unit through maternal oral supplementation. STUDY DESIGN: In a randomized, double-blind study, 20 women received a daily prenatal vitamin with or without 400 IU of vitamin E and 500 mg of vitamin C, starting at 35 weeks' gestation. At randomization, a nutritional questionnaire, plasma vitamin C and E and red blood cell (RBC) vitamin E levels were determined. At delivery, concentrations of maternal and fetal plasma vitamin C and E, maternal and fetal RBC vitamin E, amniotic fluid vitamin C, and chorioamnion vitamin E and tensile strength were determined. RESULTS: Maternal plasma vitamin E levels increased in the supplemented women but not in the control subjects. No changes in maternal vitamin C levels were noted. Maternal plasma vitamin C concentrations at delivery correlated closely with amniotic fluid vitamin C levels. Similarly, maternal plasma vitamin E levels at delivery correlated with the chorioamnion concentration of vitamin E. CONCLUSIONS: Maternal plasma vitamin E levels are increased by oral supplementation. Maternal plasma vitamin C and E concentrations correlate with the concentration of vitamin C in the amniotic fluid and vitamin E in the chorioamnion, respectively.     

Activated protein C resistance in cord blood from healthy and complicated newborns.

OBJECTIVES: Newborns are susceptible to thrombosis secondary to the immature hemostatic system and maternal and fetal complications. The contribution of activated protein C resistance (APCR) to thrombosis tendency has not yet been established. This study was conducted to investigate the effects of maternal and fetal complications on APCR levels. METHODS: APCR levels were determined in cord blood from healthy term infants and compared with those in healthy preterm and complicated neonates as well as that in adult venous blood. RESULTS: The mean value of APCR in cord blood from healthy term infants (166 +/- 40 s) was not significantly different from that in adult venous blood (173 +/- 40 s). No significant differences in the mean cord blood APCR values were observed between healthy term and preterm infants, infants with vaginal and cesarean delivery, infants from preeclamptic and non-eclamptic mothers, and infants with or without perinatal asphyxia. The activity levels of protein C, protein S, and antithrombin III were not significantly different between these groups except for lower levels in preterm babies. CONCLUSIONS: The level of APCR in cord blood is comparable to that in adults and not influenced by maternal and fetal complications. It appears that APCR does not contribute to the thrombotic tendency in newborns.     

The role of calcium, copper, iron and zinc in preterm delivery and premature rupture of fetal membranes

Maternal and cord blood samples were collected in 60 cases with or without rupture of membranes before and at term. Serum concentrations of calcium, copper, iron and zinc were determined by proton-induced X-ray emission. Maternal and cord serum ceruloplasmin and maternal hemoglobin were also determined. Mothers with preterm delivery showed significantly lower hemoglobin values than those with delivery at term. Concentrations of calcium, iron and zinc were higher in cord than in maternal serum whereas maternal copper levels were higher than respective cord levels in all groups. The cord copper and ceruloplasmin and also their fetal/maternal ratios were significantly lower in the group with preterm premature rupture of fetal membranes (PROM) than in other groups. Maternal serum zinc and calcium were lower in preterm groups than in term groups. The study suggests a possible role of copper in preterm PROM and of zinc in the initiation of preterm labor, whereas calcium and iron do not seem to be involved in the etiology of prematurity or PROM.     

Umbilical cord plasma interleukin-6 concentrations in preterm infants and risk of neonatal morbidity

OBJECTIVE: This study was undertaken to evaluate the association between umbilical cord interleukin-6 (IL-6) levels and neonatal morbidity in infants born at less than 32 weeks' gestation. STUDY DESIGN: Umbilical cord plasma IL-6 levels and neonatal outcomes were assessed in 309 infants born between 24 weeks and 0 days' and 31 weeks and 6 days' gestation. RESULTS: Mean IL-6 levels were higher in spontaneous (n = 193, 355 +/- 1822 pg/mL) compared with indicated preterm births (n = 116, 37 +/- 223 pg/mL, P < .0001). Adjusting for gestational age, a progressive relationship was noted between increasing IL-6 levels and increased risk of neonatal systemic inflammatory response syndrome (SIRS). IL-6 levels beyond the 90th percentile (> or =516.6 pg/mL) were also significantly associated with periventricular leukomalacia (PVL; odds ratio [OR] 15, 95% CI 2-149) and necrotizing enterocolitis (NEC; OR 6, 95% CI 1.1-33). In the multivariate analysis, an IL-6 level 107.7 pg/mL or greater (determined by receiver operating curve analysis) remained a significant independent risk factor for PVL (OR 30.3, 95% CI 4.5-203.6). CONCLUSION: Umbilical cord IL-6 levels are higher in preterm infants born after spontaneous preterm labor or premature rupture of membranes. Elevated IL-6 levels are associated with an increased risk for SIRS, PVL, and NEC in infants born at less than 32 weeks' gestation.     

The preterm prediction study: granulocyte colony-stimulating factor and spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network

OBJECTIVE: Granulocyte colony-stimulating factor is elevated in the amniotic fluid and plasma of women with chorioamnionitis and active preterm labor. We investigated the relationship between plasma granulocyte colony-stimulating factor and subsequent spontaneous preterm birth in pregnant women without symptoms. STUDY DESIGN: We performed a nested case-control study involving 194 women who had a singleton spontaneous preterm birth and 194 matched term control subjects from the patient pool (n = 2929) enrolled in the Preterm Prediction Study. Plasma collected at 24 and 28 weeks' gestation was analyzed for granulocyte colony-stimulating factor, and the results were compared with subsequent spontaneous preterm birth. RESULTS: Compared with term control subjects, women who were delivered of their infants spontaneously at <28 weeks' gestation had increased mean granulocyte colony-stimulating factor values at 24 weeks' gestation (84.7 +/- 38.4 vs 67.7 +/- 28.6 pg/mL; P =.049), and women who were delivered of their infants at <32 weeks' gestation had increased mean plasma granulocyte colony-stimulating factor values at 28 weeks' gestation (80.4 +/- 24.1 vs 55.9 +/- 16.5 pg/mL; P =. 001). At 24 weeks' gestation a granulocyte colony-stimulating factor value >75th percentile in control subjects (approximately 80 pg/mL) was found in 48.9% (23/47) of all women delivered of their infants at <32 weeks' gestation versus 14.9% (7/47) of the term control subjects (adjusted odds ratio, 6.2; 95% confidence interval, 1.8-20. 8). At 28 weeks' gestation a granulocyte colony-stimulating factor value >75th percentile was found in 36.8% (7/19) of women delivered of their infants at <32 weeks' gestation versus 5.3% (1/19) of term control subjects (adjusted odds ratio, 25.7; 95% confidence interval, 1.5-470.4). When measured at 24 or 28 weeks' gestation, granulocyte colony-stimulating factor did not predict spontaneous preterm birth at 32 to 34 weeks' gestation or at 35 to 36 weeks' gestation. CONCLUSION: In pregnant women without symptoms at 24 and 28 weeks' gestation, elevated plasma granulocyte colony-stimulating factor levels are associated with subsequent early (<32 weeks' gestation) spontaneous preterm birth, especially within the next 4 weeks, but not with late spontaneous preterm birth. These data provide further evidence that early spontaneous preterm birth is associated with an inflammatory process that is identifiable by the presence of a cytokine in maternal plasma several weeks before the early spontaneous preterm birth; however, later spontaneous preterm birth is not associated with this process.     

Activated protein C resistance in cord blood from healthy and complicated newborns

Objectives. Newborns are susceptible to thrombosis secondary to the immature hemostatic system and maternal and fetal complications. The contribution of activated protein C resistance (APCR) to thrombosis tendency has not yet been established. This study was conducted to investigate the effects of maternal and fetal complications on APCR levels.

Methods. APCR levels were determined in cord blood from healthy term infants and compared with those in healthy preterm and complicated neonates as well as that in adult venous blood.

Results. The mean value of APCR in cord blood from healthy term infants (166 ± 40 s) was not significantly different from that in adult venous blood (173 ± 40 s). No significant differences in the mean cord blood APCR values were observed between healthy term and preterm infants, infants with vaginal and cesarean delivery, infants from preeclamptic and non-eclamptic mothers, and infants with or without perinatal asphyxia. The activity levels of protein C, protein S, and antithrombin III were not significantly different between these groups except for lower levels in preterm babies.

Conclusions. The level of APCR in cord blood is comparable to that in adults and not influenced by maternal and fetal complications. It appears that APCR does not contribute to the thrombotic tendency in newborns.     

Immunoglobulins in prolonged ruptured membranes

Concentrations of immunoglobulins G, M, and A were studied in maternal and cord serum of patients with prolonged premature rupture of membranes, as well as in properly matched control patients. None of the patients studied showed any evidence of clinical chorioamnionitis or other prenatal infections. Cases were divided into term premature rupture of membranes and term controls and preterm (less than 34 gestational weeks) premature rupture of membranes and preterm controls. In the term group, with 12 to 24 hours of premature rupture of membranes, maternal immunoglobulins M and A, and cord immunoglobulin A were significantly increased. With a duration of premature rupture of membranes of more than 24 hours, levels of immunoglobulins M and A in maternal serum and levels of immunoglobulins G and A in cord serum showed significant elevations. Levels of cord immunoglobulin M from both subgroups of patients with premature rupture of membranes showed a trend upward but were not significantly higher than those in control patients. In the preterm group, with 12 to 24 hours of premature rupture of membranes, only cord immunoglobulin A was significantly increased. With premature rupture of membranes of greater than or equal to 72 hours, only maternal immunoglobulin G increased significantly and remained elevated; immunoglobulins M and A in cord serum were also significantly increased. The significant rise in immunoglobulins in patients with premature rupture of membranes may indicate subclinical maternal and fetal infection. This suggests the possibility that subclinical infections may play a role in the etiology of premature rupture of membranes.     

Vitamin D supplementation in pregnancy: a controlled trial of two methods

A randomized study was conducted to evaluate the effects of single-dose and daily vitamin D supplementation in pregnant women during the last trimester of a winter pregnancy in the Northwest of France. The women were divided into three randomized groups: one (N = 21) was given a vitamin D2 supplement of 1000 IU/day during the last three months of pregnancy, one (N = 27) was given a single oral dose of 5 mg at the seventh month of pregnancy, and one (N = 29) acted as a control. Venous plasma samples were obtained at delivery from the women and from cord blood, and levels of calcium, 25-OHD, and 1,25(OH)2D were determined. No significant difference in plasma calcium concentration was found among the three groups, but within each group plasma calcium concentrations were higher in the cord samples than in the respective maternal samples. The levels of the two metabolites measured were consistently lower in the cord samples than in the respective maternal samples. Cord 25-OHD concentrations correlated with those of maternal plasma. No significant modification of maternal calciuria or of the birth weight of term infants was observed. 25-OHD concentrations were greater in maternal and cord plasma from treated mothers, but only a slight difference was observed between the supplemented groups. 1,25(OH)2D concentrations were not significantly different in the three groups. A single 5-mg dose of vitamin D given orally at the seventh month of pregnancy provides effective prophylaxis in the authors' region.     

早期新生儿骨代谢指标血清水平分析

目的 分析早期新生儿骨代谢指标血清值水平.方法 采集2018年7月至2019年12月在我院新生儿科住院的早期新生儿121例,检测血清骨代谢指标总碱性磷酸酶(ALP)、总Ⅰ型前胶原N端前肽(PINP)、β-Ⅰ型胶原交联羧基端肽区(β-CTX)、钙、磷、25-羟胆骨化醇(25-(OH)D)、甲状旁腺激素、降钙素的浓度,进行...     

Vitamin E status of infants at birth

Preterm infants may be susceptible to chronic lung disease and retinopathy of prematurity because of deficient antioxidant mechanisms including deficiency of vitamin E. The aim of this study was to evaluate the status of the antioxidant vitamin E among preterm and term livebirths. Umbilical cord blood samples collected from 40 preterm and 180 term babies were analyzed for vitamin E levels using high performance liquid chromatography. Linear regression analysis was used to examine the relationship of vitamin E with gestational age, birth weight and appropriateness of weight for gestational age. The median vitamin E level of preterm babies (2.61 mg/L) was not significantly different from that of term babies (2.77 mg/L), p = 0.2. Linear regression analysis demonstrated a weak but statistically significant correlation between cord blood vitamin E levels and gestational age (r = 0.14, p = 0.046). Vitamin E levels did not correlate with birth weight or weight for gestational age. Preterm babies had a higher incidence of vitamin E deficiency compared to term babies (38% v 19%, p = 0.02). Our findings lead us to conclude that vitamin E accumulates in the fetus throughout the third trimester so that preterm infants are likely to have vitamin E deficiency.     

Maternal antenatal administration of vitamin K1 results in increasing the activities of vitamin K-dependent coagulation factors in umbilical blood and in decreasing the incidence rate of periventricular-intraventricular hemorrhage in premature infants

AIMS: Infants less than 35 weeks' gestation age are susceptible to periventricular-intraventricular hemorrhage (PIVH). This may be partially attributable to low concentrations of vitamin K-dependent coagulation factors. The purposes of this study were: (1) to determine the umbilical blood activity levels of vitamin K-dependent coagulation factors II, VII, IX and X; (2) to investigate the change in activities of these factors in premature infants' umbilical blood after prenatal administration of vitamin K1 to the mothers; and (3) to study the prophylactic effects on PIVH after maternal antenatal supplemental vitamin K1. METHODS: Pregnant women in preterm labor at less than 35 weeks of gestation were randomly selected to receive antenatal vitamin K1 10 mg per day injection intramuscularly or intravenously for 2-7 days (vitamin K1 group, n = 40), or no such treatment (control group, n = 50). At the same period, cord blood samples were collected from thirty full-term neonates to compare the factor levels with those of premature infants. Intracranial ultrasound was performed by the same sonographer to determine the presence and severity of PIVH. RESULTS: The activities of vitamin K-dependent coagulation factors in umbilical blood in the control group were: factor II 25.64+/-9.49%, factor VII 59.00+/-17.66%, factor IX 24.67+/-8.88%, and factor X 30.16+/-5.02%. In full-term infants, the respective values were: factor II 36.70+/-4.88%, factor VII 64.54+/-10.62%, factor IX 30.18+/-5.69%, and factor X 34.32+/-12.63%. In vitamin K1 group these factors were: factor II 36.35+/-6.88%, factor VII 69.59+/-16.55%, factor IX 25.71+/-10.88%, and factor X 39.26+/-8.02%. The data suggest the absence of vitamin K-dependent coagulation factors in preterm infants, and antenatal supplement of vitamin K1 may increase the cord blood activity of factor II, VII and factor X (P < 0.001). In addition, the overall rates of PIVH in the vitamin K1 group and in controls were 32.4 and 52.0%, respectively (P = 0.036), and the frequency of severe PIVH was 5.0 and 20.0%, respectively (P = 0.038). CONCLUSIONS: Administration of vitamin K1 to pregnant women at less than 35 weeks' gestation age may result in improved coagulation and may reduce the incidence as well as the severity degree of PIVH.     

经阴道多胎妊娠胚胎减灭术55例临床分析

目的 分析在阴道B超引导下对早期高序多胎妊娠进行胚胎减灭术的可行性,安全性及对母儿的影响。方法 对55例经辅助生育技术受孕的早期（妊娠49－79d)多胎妊娠,在阴道B超引导下行胚胎减灭术,其中1例为7胎妊娠,7例为5胎妊娠,16例为4胎妊娠,31例为3胎妊娠。用减胎穿刺针的针尖直刺待减灭胎儿的胎心搏动（心搏）处,直至原始心搏消失,抽吸胚囊内容物,或在穿刺胚胎的同时向羊膜囊内注射生理盐水。结果 53例（96％）减胎成功,其中49例减为双胎,3例5胎减为3胎,1例7胎减为3胎,失败2例,均为4胎妊娠,其中1例为术中流产,1例为未减灭。术后流产8例（流产率15％）;早产21例,其中5名早产儿于出生后1－2d内死亡,未见畸形;足月分娩24例,共出生新生儿87名（包括42名早产儿）,82名新生儿存活,除1名为六指畸形,1名为房间隔缺损外,其余新生儿均健康,无畸形,无脏器损伤,血管损伤大出血及术后感染,发热等。结论 妊娠早期经阴道施行胚胎减灭术是一种定位准确,操作简单,易行,安全有效的手术。     

早产儿维生素A营养不良及其补充治疗的临床研究

目的　评价早产儿基础维生素A营养状况、与疾病的关系及常规补充的效果。方法　高效液相色谱法检测2006年1月至2007年2月北京大学第一医院出生24 h 内的早产儿（147名）血浆视黄醇浓度,足月儿（40名）脐血作为对照。根据临床治疗常规,早产儿静脉（1650 U/d）和（或）口服（750 U/d）补充维生素A,随 访早产儿血浆视黄醇浓度。结果　出生时,早产儿血浆视黄醇浓度低于足月儿,差异有统计学意义,分别为（0.161±0.051）μg/mL 和 （0.187±0.055） μg/mL（P = 0.005）。早产儿维生素A 缺乏（VAD）发生率高于足月儿,但差异无统计学意义。多元线性回归分析显示出生体重与血浆视黄醇浓度呈正相关。31 例早产儿补充维生素A 2周后,随访血浆视黄醇浓度显著升高,分别为（0.168±0.046） μg/mL和 （0.203±0.063）μg/mL（P = 0.014）;VAD发生率显著下降 ,分别为100%和48%（P < 0.001）。未发现补充剂量、方式对随访维生素A浓度的影响,未发现出生时血浆视黄醇浓度与新生儿期疾病的关系。结论　早产儿基础 维生素A营养状况不良,常规补充可在一定程度上改善2周时维生素A营养状况。     

Vitamins C and E: missing links in preventing preterm premature rupture of membranes?

We propose that generation of reactive oxygen species may be a potentially reversible pathophysiologic pathway leading to preterm premature rupture of the membranes. Reactive oxygen species generated by the body's response to diverse insults such as infection, cigarette smoking, bleeding, or cocaine use can activate collagenolytic enzymes and impair fetal membrane integrity. Vitamin E, a lipid-soluble antioxidant, inhibits membrane-damaging effects of reactive oxygen species-induced lipid peroxidation. Vitamin C, a water-soluble antioxidant in plasma, stimulates and protects collagen synthesis while recycling vitamin E. Prior evidence shows that (1) damage by reactive oxygen species can impair fetal membrane integrity, (2) reduced midgestation levels of vitamin C are associated with preterm premature rupture of membranes, and (3) these vitamins can be safely and effectively absorbed and delivered to gestational tissues. Current prenatal vitamin preparations contain vitamins C and E in concentrations that are less than 1/3 and 1/10, respectively; these levels have been suggested for effective antioxidant protection. We hypothesize that increased dietary consumption or supplementation of vitamins C and E during pregnancy may reduce physiologically the risks of that portion of preterm premature rupture of membranes that is mediated by excessive or undamped peroxidation of fetal membranes. This hypothesis, if confirmed, should stimulate initiation of therapeutic trials to test the efficacy of enhanced supplementation with vitamins C and E during pregnancy to prevent preterm premature rupture of membranes.     

Total complement activity in maternal sera, amniotic fluids and cord sera in women with premature labor, premature rupture of membranes or chorioamnionitis

Total hemolytic complement activity (CH50) was determined in maternal sera, amniotic fluids or cord sera, or all, from 119 patients with preterm uterine contractions, premature rupture of membranes or chorioamnionitis, or all, at 24 to 40 weeks of gestation. The mean CH50 of maternal sera exceeded the mean CH50 of both amniotic fluids and cord sera. The mean CH50 of amniotic fluids exceeded that of cord sera and increased significantly at 32 weeks. This rise preceded that of the mean CH50 of cord sera, which occurred at a fetal weight of approximately 2,500 grams. The mean CH50 of amniotic fluids varied significantly and inversely with that of cord sera. The levels of CH50 in these three fluids did not distinguish between patients with preterm uterine contractions who delivered prematurely and those who delivered at term. The CH50 in patients with premature rupture of membranes did not differ from a control population of women with uncomplicated pregnancies. The mean CH50 of maternal sera was increased in patients with chorioamnionitis but was not predictive of chorioamnionitis. The mean CH50 of maternal sera was decreased in patients who smoked cigarettes and in patients who received intravenous ritodrine.     

Maternal and placental responses before preterm birth: adaptations to increase fetal thyroid hormone availability?

Background: During pregnancy, maternal thyroid hormone supply is crucial for fetal development. Preterm infants often present with hypothyroxinemia. Preterm birth, either spontaneous or medically indicated, is always the result of a complicated pregnancy. We hypothesized that in preterm birth, the maternal transplacental thyroid hormone supply is influenced by the pregnancy complication and we questioned whether maternal and placental compensatory mechanisms are activated to increase thyroid hormone transfer.

Methods: Observational case-control study in mother–infant-dyads with complicated pregnancies ending in spontaneous preterm birth (n?=?31) or indicated preterm birth due to vascular complications (n?=?45) and normal pregnancies (healthy term controls; n?=?41). At delivery, maternal and cord blood and placenta samples were collected. Cord and maternal plasma concentrations of thyroid stimulating hormone (TSH), total T4, fT4/FTI, total T3, and T4 binding globulin (TBG), and maternal serum concentrations of thyroid peroxidase (TPO)-antibodies were measured. Placental maturity was evaluated histologically and mRNA and/or protein levels of thyroid hormone deiodinases (DiO) 1, 2 and 3, and transporters (MCT8, MCT10, and OATP1c1) were quantified.

Results: In indicated and spontaneous preterm births, cord plasma T4 concentrations were lower than in healthy term controls (p?≤?.001), whereas T3 was only decreased in spontaneous preterm birth (p?≤?.001). Compared with spontaneous preterm births and healthy term controls, indicated preterm birth was characterized by higher maternal plasma TSH (p?≤?.05), earlier placental maturation, higher placental DiO2 gene and MCT10 protein levels and lower DiO3 gene levels (all p?≤?.01).

Conclusions: Low T4 was observed in preterm infants irrespective of the cause of preterm birth, while maternal (TSH) and placental (DiO2, DiO3, and MCT10) compensatory responses were only activated in indicated preterm birth due to vascular complications. This may have mediated the normal fetal T3 availability in preterm infants born after indicated preterm birth but not after spontaneous preterm birth.     

Relationship between cortisol levels in umbilical cord plasma and development of the respiratory distress syndrome in premature newborn infants.

The aim of this study was to determine whether there is a decrease in fetal cortisol levels associated with the respiratory distress syndrome (RDS). Eighteen newborn infants of less than 37 weeks' gestation who developed moderate to severe forms of RDS did have a significantly lower (P less than 0.02) mean cord plasma cortisol concentration at birth than that observed in 67 unaffected infants of similar gestational age; mean values +/- standard errors were 3.36 +/- 0.42 and 5.58 +/- 0.43 mug per 100 ml, respectively. However, whether or not RDS developed in neonates appeared to depend more upon the degree of prematurity (with a 71.5% incidence in gestations of less than 32 weeks compared to 17.1% in those of 32 to less than 37 weeks) than upon cortisol levels at delivery. Bood cortisol levels in the first days of life of four infants with RDS were considerably increased in comparison to those at birth. Mean cord plasma cortisol concentrations increased with duration of pregnancy, with the previously observed value for term infants (of 37 or more weeks) being approximately twice that for infants of less than 32 weeks' gestation. These findings appear to justify carefully controlled studied with antepartum glucocorticoid administration with the aim of reducing the incidence of RDS in premature newborn infants.