Maternal basal metabolic rate in twin pregnancy

OBJECTIVE: This study examined the basal metabolic rate in patients with twin pregnancies and compared the results with those of singleton pregnancies and non-pregnant women. METHODS: In 15 non-pregnant women, 14 patients with twin and 25 patients with singleton pregnancies, the resting energy expenditure was measured using an open-circuit ventilatory system during the third trimester of pregnancy. RESULTS: The averaged resting energy expenditure in patients with twin pregnancy was 1,636 +/- 174 kcal/day, significantly higher than that in patients with singleton pregnancy (1,456 +/- 158 kcal/day; p < 0.05). Both of these levels are significantly higher than those in non-pregnant women (1,228 +/- 132 kcal/day; p < 0.05). CONCLUSION: Our results indicate that the estimated increased metabolic demands in patients during the third trimester of twin pregnancy are about 10% higher than those in women with singleton pregnancy. A prospective clinical study concerning nutrition counseling is needed.     

Maternal peripheral T helper 1-type and T helper 2-type immunity in women during the first trimester of twin pregnancy

Introduction This study investigated the T helper Th1:Th2 balance in twin pregnancies compared with singleton pregnancies during the first trimester.Methods Blood samples were taken from 24 women with a singleton pregnancy and 14 women with twin pregnancy at 8–9 weeks gestation to examine the ratios of Th1:Th2 and serum human chorionic gonadotropin (hCG) and progesterone levels.Results The average ratio of Th1:Th2 in the twin pregnancies was significantly lower than that in singleton pregnancies (7.3±2.3 vs. 10.5±2.2, p<0.05). There were negative correlations between the Th1:Th2 ratio and serum hCG levels (mIU/ml) (Th1:Th2 ratio = 14.5–4.52×10^–5×hCG, r²=0.41, p<0.05) and between the Th1:Th2 ratio and serum progesterone levels (ng/dl; Th1:Th2 ratio = 23.0–0.63 × progesterone, r²=0.36, p<0.05).Conclusion Our findings show marked predominance of Th2 type cytokines occurring in twin pregnancies is related to the increase in trophoblasts during the first trimester.     

Maternal cardiovascular adaptations to twin pregnancy

Multiple pregnancy places increased demands on the maternal circulation. Maternal left ventricular size and performance were measured with M-mode echocardiography in women with twin pregnancy in the second and third trimesters, and the findings were compared to those in normal singleton pregnancies. As expected, cardiac output was greater during twin than during singleton pregnancy; however, end-diastolic ventricular dimension was not. Output was increased in twin pregnancy during the second and third trimesters by heart rate and also during the third trimester by stroke volume. Increased stroke volume was effected by increased shortening, thus strongly suggesting increased contractility. Increased maternal heart rate and contractility during multiple gestations suggest that cardiovascular reserve is reduced.     

Respiratory function in singleton and twin pregnancy

Objective Singleton pregnancy causes important changes in respiratory function. The incidence of twin pregnancies is increasing, but it is not known whether affected women suffer greater respiratory compromise. The aim of this study was to determine if changes in respiratory function during pregnancy in healthy women were greater in those with a twin pregnancy compared with those with a singleton pregnancy.
Design Cross sectional study.
Setting London teaching hospital.
Population Healthy pregnant women attending the antenatal clinic and ultrasound department.
Methods A cross sectional study of respiratory function was performed in 68 women with twin pregnancies (17 examined in the first trimester, 35 second trimester, 16 third trimester) and 140 women with singleton pregnancies (28, 80, 40, respectively) and 22 non-pregnant women. Women were examined once between 7 and 40 weeks of gestation. Forced vital capacity, relaxed vital capacity, forced expiratory volume in 1 second (FEV1), peak flow, inspiratory capacity, functional residual capacity (FRC), expiratory reserve volume, pulmonary diffusing capacity and minute ventilation were measured.
Results Both in twin and singleton pregnancies, the mean FRC and expiratory reserve volume of women studied in the third trimester and minute ventilation of women studied in each trimester differed significantly from that of the non-pregnant women. There were, however, no significant differences demonstrated in respiratory function between healthy women with twin as compared with singleton pregnancies.
Conclusion In healthy women, the extra demands of a twin compared with a singleton pregnancy do not compromise further the respiratory system.     

Comparison of the lactate-pyruvate ratio during labour and delivery in singleton and twin pregnancy

Oxygen utilisation at the tissue level was investigated by the use of lactate-pyruvate (LP) ratio in forty women; twenty with term twin pregnancy, with a matched controlled group of twenty women with term singleton pregnancy. The lactate-pyruvate ratio in twin pregnancy was significantly higher than in singleton pregnancy at term (p < 0.05). There was also significantly higher LP ratio in advanced labour in twin pregnancy than in singleton pregnancy (p < 0.001). Similarly, the venous cord blood LP ratio of twin II was higher than in twin I. Our findings have thus demonstrated more marked anaerobic metabolism in twin pregnancy than in singleton pregnancy. Secondly, the second twin is more involved in anaerobic metabolism as a result of relative oxygen deficiency, than twin I. This may to some extent account for the higher morbidity and mortality in twin pregnancy, compared to singleton pregnancy, and in twin II compared to twin I. Received: 20 March 1995 / Accepted: 25 July 1995     

The procoagulant activity of red blood cells from patients with severe preeclampsia

OBJECTIVE: Our purpose was to determine whether red blood cells from patients with severe preeclampsia may exhibit increased membrane exposure of procoagulant phospholipids (i.e., phosphatidylserine), which may initiate intravascular clotting and platelet activation. STUDY DESIGN: The study group comprised 28 women: 9 with severe preeclampsia in the third trimester of pregnancy, 10 normotensive with uncomplicated pregnancies, and 9 age-matched, nonpregnant, healthy women. The exposure of phosphatidylserine on the outer membrane phospholipid layer was analyzed with use of isolated, washed red blood cells that were added as a source of phospholipids to a “prothrombinase” coagulation complex. RESULTS: The resultant thrombin formed was measured by an amidolytic assay. Thrombin generation significantly increased on the addition of red blood cells from women with preeclampsia (741 ± 132 mU/ml/min) compared with red blood cells from normotensive pregnant (422 ± 228 mU/ml/min) and nonpregnant women (316 ± 268 mU/ml/min, p = 0.0008). CONCLUSION: This study indicates that in patients with preeclampsia the red blood cells exhibit a significant procoagulant surface that may trigger thrombin formation, thereby playing a role in the hypercoagulable state.(Am J Obstet Gynecol 1997;177:6)     

Reduction of twin pregnancy to singleton: does it improve pregnancy outcome?

Objective.?To compare pregnancy complications, obstetrical and neonatal outcome of twin pregnancies reduced to singleton, with both non-reduced twin pregnancies and singleton pregnancies.

Methods.?A retrospective case–control study was performed at the Obstetrics and Gynecology Ultrasound unit of a tertiary referral medical center. Patient's population included 32 bi-chorionic bi-amniotic twin pregnancies reduced to singleton and 35 non-reduced twin pregnancies. Thirty-six patients with singleton pregnancies comprised the second control group. Main outcome measures were rates of pregnancy complications, preterm delivery (both before 37 weeks of gestation and before 34 weeks of gestation), late abortions, intra-uterine growth retardation, cesarean section, mean birth weights, and mean gestational age at delivery.

Results.?The reduced twin pregnancies group had similar rates of total pregnancy complications, preterm deliveries, and cesarean section as non-reduced twins. Gestational age at delivery and mean birth weight were also similar to non-reduced twins and significantly different compared with singletons. Preterm delivery and late abortion incidences were significantly higher when reduction was beyond 15 weeks gestation.

Conclusions.?Reduction of twin pregnancy to singleton does not change significantly pregnancy course and outcome. Favorable obstetrical and neonatal outcomes could be achieved by performing early, first trimester reductions.     

Elevated maternal plasma corticotropin releasing hormone levels in twin gestation

The placenta secretes large amounts of the hypothelamic hormone, corticotropin releasing hormone (CRH) into the maternal and fetal circulation during pregnancy. We and other investigators have shown that during normal pregnancy, maternal plasma CRH levels begin to rise in the second trimester with a dramatic increase in CRH levels during the 5-6 weeks preceding the onset of labor. This rise in maternal plasma CRH is parallel to the rise of placental CRH mRNA which has been reported to occur with gestational maturation. Mechanisms underlying the control of CRH secretion by the placenta have not yet been determined. In twin gestation, increased fetal-placental mass has been shown to be associated with elevated maternal levels of several placental hormones as compared to singleton gestation. We measured maternal plasma CRH in both twin and singleton gestation to investigate whether the larger size of the fetal-placental unit in twin gestation is associated with elevated maternal CRH levels. Seventy-six serial venous blood samples were collected from 20 women with twin gestation and 40 samples were obtained from 27 women with uncomplicated singleton gestation. Gestational age was determined by history of a known last menstrual period and first trimester clinical examination and confirmed by ultrasound examination. CRH was extracted from 1-2 ml plasma with SEP-Pak C18 cartridges and eluted with triethylamine-formic-acid propranolol. CRH was measured by radioimmunoassay (RIA) with human CRH standard and antiserum to human CRH raised in our laboratory. Mean CRH levels were calculated for four week intervals. In both singleton and twin gestation, the maternal plasma CRH levels increased with advancing gestational age. After 29 weeks of gestation, maternal plasma CRH levels in twin gestation were significantly higher than those in singleton gestation (p less than 0.01). At 37 to 40 weeks of gestation, mean maternal CRH was 1167 +/- 237 pg/ml in singleton gestation as compared to 6927 +/- 1725 pg/ml in twin gestation (p less than 0.05). In addition, the rapid rise in plasma CRH levels which occurs near term in singleton gestation, occurred earlier in twin gestation. This early rise in maternal CRH levels persisted when the data from twin pregnancies complicated by preterm labor were removed from the analysis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Predictive value of serum kisspeptin concentration at 14 and 21 days after frozen–thawed embryo transfer

Research questionCan serum kisspeptin levels 14 and 21 days after frozen–thawed embryo transfer predict the early pregnancy outcome of patients?DesignProspective study, with 133 patients undergoing frozen–thawed embryo transfer. Patients were divided into non-pregnant group and pregnant group (including biochemical pregnancy, singleton pregnancy, miscarriage and twin groups).ResultsSerum kisspeptin levels on day 21 were significantly higher than day 14 in singleton pregnancy, miscarriage and twin groups (all P < 0.0001), but not in the biochemical pregnancy group. Similarly, serum human chorionic gonadotrophin (HCG) levels were higher on day 21 compared with day 14 except for the biochemical pregnancy group. Compared with the twin group (296.9 pg/ml), the other four groups showed significantly higher serum kisspeptin levels on day 14 (non-pregnant 548.9, biochemical pregnancy 440.4, miscarriage 434.9, singleton pregnancy group 420.9 pg/ml, P < 0.01, P = 0.016, P = 0.034, P = 0.036, respectively). The miscarriage (762.2 pg/ml), singleton pregnancy (730.8 pg/ml) and twin groups (826.3 pg/ml) had significantly higher kisspeptin levels than the biochemical pregnancy group (397.3 pg/ml) on day 21 (P < 0.001, P < 0.01, P < 0.001, respectively). Serum kisspeptin levels on day 14 were negatively correlated with embryo implantation rate (P = 0.035, R² = –0.880). Serum kisspeptin levels on day 21 have a poor predictive value of miscarriage compared with serum HCG levels (area under the curve = 0.53 and 0.78, respectively).ConclusionsSerum kisspeptin levels on day 14 are negatively correlated with embryo implantation rate. Serum kisspeptin levels on day 21 have a poor predictive value of miscarriage.     

Maternal serum Ca125 and Ca15-3 antigen levels in normal and pathological pregnancy

OBJECTIVE: To evaluate the value of maternal serum CA125 and CA15-3 concentrations for discriminating pathological from normal pregnancies. METHODS: Serum samples from 120 women, in whom pregnancy outcome was pathological, i.e. spontaneous abortion, fetal death, intrauterine growth retardation, chromosomal and structural abnormalities, and (pre)eclampsia, were assessed for CA125 and CA15-3 and compared with levels found in 350 women with a normal pregnancy outcome matched for age and duration of pregnancy. RESULTS: Maternal CA125 serum values were significantly higher in the first and the third trimester of pregnancy (median 23.0 and 21.0 U/ml; p < 0.00001 and p < 0.001, respectively), compared to those in the second trimester (median 14.0 U/ml), but not significantly different from those obtained in pathological pregnancies. Maternal serum CA15-3 values were significantly higher during the third trimester (median 26.0 U/ml) compared to the first and second trimester of pregnancy (median 14.0 and 15.0 U/ml; p < 0.0001); CA15-3 serum levels in normal and pathological pregnancies showed no significant difference. CONCLUSION: Maternal serum levels of CA125 are higher during the first and third trimester of pregnancy. CA15-3 maternal serum levels are higher during the third trimester compared to the first and second trimester. Maternal CA125 and CA15-3 serum levels showed no relation with a pathological outcome of pregnancy.     

SRY-specific cell free fetal DNA in maternal plasma in twin pregnancies throughout gestation

Objectives

Levels of SRY-specific cell free fetal DNA (SRY-cffDNA) in maternal plasma were investigated in twin pregnancies with two male fetuses versus one male and one female fetus and singleton male pregnancies during second and third trimester. The aim was to evaluate at which gestational age the amount of SRY-cffDNA reflects the number of fetuses and placentas respectively.

Methods

251 venous blood samples were analyzed from a total of 178 women with male or mixed-gender twin pregnancies and male singleton pregnancies in the second and the third trimester. The concentration of SRY-cffDNA was determined by quantitative real time PCR using the Y-chromosome specific SRY assay. For statistical analysis these three groups were divided into four subgroups according to their gestational age.

Results

During second trimester levels of SRY-cffDNA showed no differences between twin and singleton pregnancies. After 28 weeks SRY-cffDNA of male twin pregnancies was significantly increased compared to singleton male pregnancies and mixed-gender twin pregnancies with no differences between the latter two.

Conclusion

The level of SRY-cffDNA in maternal serum of twin pregnancies reflects the number of fetuses only during the third trimester. Hence its use as a diagnostic tool for complications related to altered SRY-cffDNA levels in twin pregnancies should be evaluated at different weeks of gestation, especially during the second trimester.     

Hemodynamic changes during twin pregnancy. A Doppler and M-mode echocardiographic study

Serial hemodynamic investigations were performed in 10 women with twin pregnancies at 20, 24, 28, 32, and 36 weeks' gestation and at 6 months after delivery. Cardiac output was measured by Doppler and cross-sectional echocardiography at the aortic, pulmonary, and mitral valves. Cardiac chamber size and ventricular function were investigated by M-mode echocardiography. The hemodynamic results were compared with those of 13 women with singleton pregnancies. Mean Doppler cardiac output was increased at 20 weeks of twin pregnancy (7.63 L/min) and showed no significant change during the remainder of pregnancy, but fell to 5.07 L/min after delivery. This increase was significantly greater than that recorded during singleton pregnancy, because of a relatively greater increase in heart rate. Twin pregnancy was associated with a significantly greater increase in left atrial dimension, but the increases in left ventricular dimensions, wall thickness, and function were comparable to those recorded in singleton pregnancy.     

The correlation in birth timing between singleton and twin gestations in the same mother

Objective. To test the hypothesis that the timing of twin births is correlated to that of their singleton siblings.

Methods. Using the Missouri Department of Health's birth certificate database we performed a retrospective population-based cohort study of 2222 women who had at least one singleton and one twin birth (1989–1997). Pearson correlation analysis was conducted to examine the relationship in gestational age between singleton and twin births occuring in the same mother.

Results. Among 2222 mothers who had both a singleton and twin pregnancy during the study period, the mean difference in birth timing between singleton and twin siblings was 3.05 weeks (±2.9 weeks). The correlation between singleton and twin birth timing was statistically significant (r = 0.28, p < 0.001), and remained significant even after controlling for potential confounders (β = 0.459, p < 0.001).

Conclusions. We identified a significant correlation in the timing of birth between singleton and twin pregnancies in the same mother, which could be due to shared genetic, environmental, medical, social and other influences. This finding could be useful to help predict birth timing in mothers at especially high risk of preterm birth, those with a twin gestation.     

Maternal heart rate changes during labour

Objectives

Labour and delivery represent a considerable effort for pregnant women. Lack of aerobic fitness may limit pushing efforts during childbirth and represents increased cardiovascular strain and risk. Increasing prevalence of sedentary behaviour and lack of aerobic fitness may reduce heart rate reserve during labour.

Study design

We quantified maternal heart rate reserve (maximum heart rate minus resting heart rate) of 30 healthy pregnant women during labour and delivery and related it to habitual daily physical activity levels quantified during the third pregnancy trimester by the Pregnancy Physical Activity Questionnaire.

Results

Heart rates during labour reached values similar to those observed during moderate to heavy physical exercise. During active pushing one out of five women reached heart rates more than 90% of their heart rate reserve (188 ± 7 beats per min). Half of the women reached more than 70% of heart rate reserve (172 ± 14 beats per min). Physically inactive women used more of their heart rate reserve as physically more active women (87 ± 20% vs. 65 ± 12%, upper and lower tertile respectively, p < 0.05).

Conclusions

Use of heart rate reserve for the effort of labour is increased in physically inactive women and may potentially limit the intensity and duration of pushing efforts. Such higher cardiovascular strain in physically less active women may represent increased cardiovascular risk during labour.     

Intravenous glucose tolerance tests in women with twin pregnancy

Carbohydrate metabolism was evaluated in 20 twin gestations and 20 singleton pregnancies. The groups were matched for age, parity, weight, height, and gestational age. Intravenous glucose tolerance tests were performed on all women in the third trimester of pregnancy using a glucose load of 0.5 g/kg body weight. Venous plasma glucose and insulin level were measured and statistically compared. The glucose disappearance rates (K) were not different in the two groups. No significant differences in the mean insulin or glucose responses were found between singleton and twin pregnancies. Thus, twin gestations are not at higher metabolic risk of gestational diabetes than are singleton pregnancies.     

Placental isoferritin: a new serum marker in toxemia of pregnancy

The serum concentrations of placental isoferritin and normal ferritin were determined in 20 patients with preeclamptic toxemia of pregnancy and were compared with the level measured in normal pregnant women at the third trimester and in labor at term. The mean serum concentration of placental isoferritin for the women with preeclamptic toxemia was found to be low: 7.5 +/- 23 U/ml compared with 81.6 +/- 89.3 U/ml in normal pregnancy during the third trimester and 54.8 +/- 53 U/ml in term delivery. In comparison, there was no significant difference in the serum levels of normal ferritin in both pregnant women with toxemia and in those without toxemia. These results suggest that placental isoferritin may be a useful marker for preeclamptic toxemia of pregnancy.     

Can early β-human chorionic gonadotropin predict birth of singletons and twins after in vitro fertilization?

Objective: To assess the predictive value for clinical pregnancy outcome of β-hCG level at 13?d after embryo transfer.

Methods: Retrospective study of IVF clinical pregnancies diagnosed at 6 weeks. We calculated the value of β-hCG level at 13?d after embryo transfer to predict live births.

Results: We analyzed 177 IVF cycles between 2009 and 2014 (50 singleton births, 50 twin births, 27 sets with a vanishing twin, 43 first trimester singleton pregnancy loss and seven first trimester total twin pregnancy loss). Singleton pregnancies with a β-hCG concentration?<85 mIU/mL had an 89% risk of having a first trimester loss whereas a concentration?>386?mU/mL had a 91% chance of a live birth. Twin pregnancies with a concentration?<207 mIU/mL had only a 33% chance of delivering twins and a 55% risk of having a vanishing twin; whereas a level?>768 mIU/mL was associated with a 81% chance of live twin birth and a low risk (19%) of having a vanishing twin. Age, type and duration of infertility, body mass index (BMI) and number of fertilized oocytes did not affect these calculations.

Conclusions: β-hCG level at 13?d after embryo transfer might predict outcomes in clinical singleton and twin pregnancies following IVF.     

Hypoproteinemia in the second trimester among patients with preeclampsia prior to the onset of clinical symptoms

Objective: To find a risk factor for “uncomplicated” preeclampsia (PE) comparing blood biochemical parameters between women with uncomplicated PE and healthy pregnant women in each trimester of pregnancy. Methods: A retrospective study was performed on 83 cases of uncomplicated PE, selected from 434 patients with PE, disregarding subjects with other complications relevant to hypertension during pregnancy. The study was limited to women with PE occurring in the third trimester, and records of blood biochemical parameters were evaluated. Controls were recruited from 108 healthy volunteers with normal singleton pregnancies. Results: A significant decrease in total protein was observed in the uncomplicated PE group in the second trimester prior to the onset of clinical symptoms. Conclusion: Hypoproteinemia during pregnancy may be a risk factor for this pathophysiology, and the maintenance of sufficient protein in early pregnancy could contribute to prophylaxis for women with uncomplicated PE.     

Influence of spontaneous fetal reduction on dichorionic diamniotic twin pregnancy outcomes after in vitro fertilization: a large-sample retrospective study

Objective: To examine the incidence of spontaneous fetal reduction during dichorionic diamniotic (DCDA) twin pregnancy after in vitro fertilization and embryo transfer (IVF-ET) and its influence on pregnancy outcomes.

Methods: This was a retrospective cohort study of 4447 DCDA twin pregnancies and 14,551 singleton pregnancies after IVF-ET at a single center between 2009 and 2015. The spontaneous pregnancy reduction (SPR) group included 759 women. The remaining 3688 women with DCDA twins showing no spontaneous reduction were included in the non-SPR group. Outcomes were compared to a singleton group (n?=?14,551) treated over the same period. The overall rate of spontaneous reduction and frequency distribution across gestational epochs were determined and pregnancy outcomes were compared among the three groups. Further regression analysis was conducted to investigate whether spontaneous reduction was an independent risk factor for decreased take-home baby rate.

Results: The overall rate of spontaneous DCDA twin reduction after IVF-ET was 17.1%, with most cases (89.8%) occurring in the first trimester. Pregnancy outcome measures, including miscarriage rate, premature delivery rate, live birth rate, take-home baby rate, gestational age of delivery, and neonatal birth weight, were significantly better in the SPR group than the non-SPR group. Live birth rate, take-home baby rate, neonatal birth weight, and other primary outcome measures in the SPR group were not inferior to the singleton group. Multivariate regression analysis showed that the take-home baby rate was significantly lower in the non-SPR group (OR =0.73, 95%CI: 0.44–0.92, p?=?.008) and that SPR did not decrease the take-home baby rate.

Conclusions: Spontaneous pregnancy reduction is common in DCDA twin pregnancy after IVF-ET, but has little adverse influence on pregnancy outcomes and does not reduce the probability of taking home live babies.     

Circulating levels of Elabela and Apelin in the second and third trimesters of pregnancies with gestational diabetes mellitus

Abstract

We design this study to detect levels of Elabela (ELA) and Apelin (APLN) in women with and without gestational diabetes mellitus (GDM) in the second and third trimesters, and to identify whether there is any association between ELA, APLN, and metabolic parameters. Seventy-nine GDM and 80 control subjects in the second trimester and 87 GDM and 88 healthy subjects in the third trimester were included. In the second trimester, lower ELA levels [(14.1 versus 16.9) ng/ml, p?=?.025] and higher APLN levels [(1021.8 versus 923.5) pg/ml, p?=?.046] were observed in GDM patients compared to controls. ELA levels were positively correlated with fasting plasma glucose (FPG) (r?=?0.423, p?<?.001) in the control group, and APLN levels were negatively correlated with triglycerides (TG) (r?=??0.251, p?=?.025) in the control group and total cholesterol (TC) (r?=??0.227, p?=?.044) in the GDM group. ELA appeared to be related to glucose metabolism and APLN is involved in lipid metabolism during pregnancy. The expression of ELA is significantly downregulated from the second trimester to the third trimester.