Maternal hemoglobin drop in multiple pregnancy is associated with higher gestational age at birth and birthweight.

INTRODUCTION: This retrospective study investigated the hypothesis that maternal hemoglobin (Hb) levels in twin pregnancy fall between the first and second trimesters and that higher falls are associated with higher gestational age at birth and higher birthweight (BW). MATERIAL AND METHODS: The study population was defined as pregnant women with twin pregnancies delivering two live, phenotypically normal neonates, after 24+0 weeks of gestation, between October 2009 and September 2021 at an inner London maternity unit. Maternal Hb and mean corpuscular volume (MCV), at ≤14+0 weeks of gestation (Hb1) and again at 20+0-30+0 weeks gestation (Hb2) were recorded from the Hospital's perinatal database. MCV was used as a possible indicator of iron deficiency anemia. The association of Hb drop, defined as [Hb1(adjusted for gestational age) - Hb2], and MCV values with gestational age at birth, BW of both twins and delivery of small for gestational age (SGA) neonates, defined as BW <10th percentile for gestation, was evaluated. RESULTS: 923 pregnant women with twin pregnancies were included. Maternal Hb1 did not correlate with any outcomes measured. However, a lower Hb2 and a larger Hb drop was associated with a higher gestational age at birth (p < 0.001), a larger BW of twin 1 and 2 (p < 0.001 for both) and a reduction in the incidence of delivering one or two SGA neonates (p < 0.001 for both). MCV values did not correlate significantly with these outcomes. CONCLUSIONS: This study showed that in twin pregnancy, a larger maternal Hb drop from the first to the second trimester is associated with a higher gestational age at birth and a larger BW. This change may represent a larger plasma volume expansion.

Cell-free DNA test for fetal chromosomal abnormalities in multiple pregnancies.

INTRODUCTION: This study aimed to report the screening performance of cell-free DNA (cfDNA) testing for chromosomal abnormalities in twins, triplets, and vanishing twin pregnancies. MATERIAL AND METHODS: Data were obtained from pregnant women with a multiple pregnancy or a vanishing twin pregnancy at ≥10 weeks' gestation who requested self-financed cfDNA testing between May 2015 and December 2021. Those that had positive screening results had diagnostic confirmatory procedures after counseling and consent. The performance of screening of the cfDNA test was determined by calculating confirmation rate and combined false-positive rate (cFPR). RESULTS: Data from 292 women were included after exclusion of those lost to follow-up, with no-result on cfDNA testing, or had reductions. Of the 292 pregnancies, 10 (3.4%) were triplets, including no cases of trisomy 21 and trisomy 18; 249 (85.3%) were twins, including 3 cases of trisomy 21 and no cases of trisomy 18 and 13; and 33 (11.3%) were vanishing twins, including 3 cases of trisomy 21 and 1 case of trisomy 18. The median (IQR) maternal age was 34 years (31-37). For triplet pregnancies, the initial no-result rate was 10.3% (95% confidence interval [CI] 3.6-26.4), all with results after redraw. For twin pregnancies, the initial no-result rate was 12.9% (95% CI 9.6-17.0), and the no-result rate after redraw was 1.6% (95% CI 0.7-3.6). For vanishing twins, there were no cases with no-result. All triplets had low-risk cfDNA results. The confirmation rate for trisomy 21 was 100% with a FPR at 0% due to the small number of positive cases for twins. For vanishing twins, one high-risk case for trisomy 21 and the only high-risk case for trisomy 18 were confirmed with a cFPR of 8.3% (n = 2/24; 95% CI 2.3-25.9). CONCLUSIONS: cfDNA testing in twin pregnancies has sufficient screening performance for trisomy 21 but the number of affected cases for other conditions is limited to draw any meaningful conclusion. The use of cfDNA testing in triplet pregnancies and vanishing twins remains an area for further research.

Is twin pregnancy, calving and pregnancy loss predictable by serum pregnancy-specific protein b (pspb) concentration 28-35 days after ai in dairy cows?

Double ovulation occurs more frequently in multiparous cows with high milk production than in primiparous cows and the rate of twin pregnancy/calving is increasing worldwide. Diagnosis of twin pregnancy is possible by ultrasound at the time of early pregnancy examination [28-34 days after artificial insemination (AI)]. Pregnancy proteins are also well-known indicators of gestation. The risk of pregnancy loss during the first trimester of gestation for cows carrying twins is three to nine times higher than for cows carrying singletons. Pregnancy-specific protein B (PSPB) is a good indicator not only of pregnancy but also of pregnancy loss. The aims of this study were (a) to collect calving data in some Hungarian Holstein-Friesian herds (n = 7,300) to compare PSPB serum concentrations (measured 29-35 days post insemination) in twin- and singleton-calving cows (Trial 1), and (b) to check the predictive value of PSPB serum concentration for twin pregnancy and pregnancy loss in high-producing Spanish Holstein-Friesian cows (n = 98; Trial 2). Our results showed almost 7% twin calving rate. Although hormonal treatments are commonly believed to be major causes of twin pregnancies, our data do not support this hypothesis. The only exception is the single PGF injection, which significantly increased twin calving. No effect of milk production on the risk of twin pregnancy was found, and twin pregnancy increased with parity. The AI bull, the bull's sire, the bull's grandfather and the cow's father also affected twin calving (P ≤ 0.02). We found much higher frequency of twin calving in cows diagnosed pregnant with higher than 3 ng/ml serum PSPB concentrations at 29-35 days after insemination. In Trial 2, non-significant but well-marked differences were found in PSPB serum concentration between singleton- and twin-pregnant cow samples (2.1 and 2.9 ng/ml) at different bleeding times. Probably the small size of the study population and the effects of milk production on PSPB values may explain this lack of significance.

Preeclampsia in high risk women is characterized by risk group-specific abnormalities in serum biomarkers.

OBJECTIVE: To determine if early pregnancy serum biomarkers in high-risk women who develop preeclampsia vary according to risk factor. STUDY DESIGN: We performed a secondary analysis of the Maternal-Fetal Medicine Units Network randomized controlled trial of low-dose aspirin for the prevention of preeclampsia in high-risk women. Serum biomarker levels at enrollment (before initiation of aspirin or placebo) were compared between women who did and did not develop preeclampsia, both for the group as a whole and within each of 4 high-risk groups (insulin-dependent diabetes, hypertension, multiple gestation, and previous preeclampsia) using a regression model adjusting for gestational age at collection and prepregnancy body mass index. RESULTS: 1258 women were included (233 with insulin-dependent diabetes, 387 with chronic hypertension, 315 with a multiple gestation, 323 with previous preeclampsia). Multiple early pregnancy serum biomarkers differed between women who did and did not develop preeclampsia. Each high-risk group had a unique and largely nonoverlapping pattern of biomarker abnormality. Differences between those who did and did not develop preeclampsia were noted in vascular cell adhesion molecule in the diabetes group; human chorionic gonadotropin, soluble tumor necrosis factor receptor-2, tumor necrosis factor-alpha, selectin and angiogenin in the chronic hypertension group; interleukin-6, placental growth factor, soluble fms-like tyrosine kinase plus endoglin to placental growth factor ratio in the multiple gestation group; and angiogenin in the previous preeclampsia group. CONCLUSION: Patterns of serum biomarkers vary by high-risk group. These data support the hypothesis that multiple pathogenic pathways lead to the disease recognized clinically as preeclampsia.

Maternal serum analyte screening for fetal aneuploidy.

In the first and second trimesters, chemicals produced by the fetoplacental unit are measured to assess risks of fetal abnormalities. Consistent associations between levels of these proteins in such pregnancies enable these biomarkers to be used to calculate risk for Down syndrome and other chromosomal abnormalities in individual pregnancies. Special consideration may be required when assessing risk in multiple pregnancies and pregnancies achieved with infertility therapy.

Anti-Müllerian hormone as an independent predictor of twin versus singleton pregnancy in fresh cycles.

This study evaluated anti-Müllerian hormone (AMH) as a possible predictor of twin pregnancy in women undergoing fresh cycles who had more than one embryo transferred. A retrospective study was performed of 139 patients undergoing fresh non-donor cycles which resulted in either singleton or twin pregnancy between 2009 and 2010 in this fertility clinic. Random serum AMH and other clinically relevant variables were compared. For further analysis, the population was stratified by age (<34 and ⩾34 years). Random serum AMH concentrations were 1.4-times greater in women conceiving twins compared with singletons (P=0.03). In women aged ⩾34, the AMH concentration in twins was 1.8-fold greater than singletons (P=0.001). Multivariate analysis demonstrated that AMH was an independent predictor of twins. ROC curve analysis showed that AMH had a significant predictive ability for twin pregnancy in women aged ⩾34 (AUC 0.67, P=0.01). In contrast, in women aged <34, AMH was not different between twin and singleton pregnancies. In summary, random serum AMH is an independent predictor of twin gestation when more than one embryo is transferred in women aged ⩾34. Considering a woman's AMH before transferring more than one embryo may assist in reducing the incidence of twins. Transferring multiple embryos to increase the chance of pregnancy and live birth rate is a common practice among assisted reproduction providers but often results in a high proportion of multiple pregnancies. Identifying factors predictive of multiple pregnancies is of paramount importance for the successful development of strategies to minimize multiple gestations. Anti-Müllerian hormone (AMH) has been shown to be closely correlated with a woman's egg reserve. Aside from the strong association of serum AMH concentration with quantitative ovarian response, serum AMH concentration has been associated with qualitative aspects of assisted reproduction such as embryo quality and pregnancy rates. Our objective was to evaluate AMH as a possible predictor of twin pregnancy in women undergoing fresh cycles who had more than one embryo transferred. Our study included 139 patients undergoing fresh non-donor cycles which resulted in either a singleton or twin pregnancy between 2009 and 2010 in our fertility clinic. Random serum AMH concentrations were compared. For further analysis, the population was divided into two groups (age <34 and ⩾34). AMH concentrations were 1.4-times greater in women conceiving twins compared with singletons. In women aged ⩾34, the AMH concentration in twins was 1.8-fold greater than singleton pregnancies. AMH was an independent predictor of twins with a significant predictive ability for twin pregnancy in women aged ⩾34. In contrast, in women aged <34, AMH was not different between twin and singleton pregnancies. In conclusion, considering a woman's AMH before transferring more than one embryo may assist in reducing the incidence of twins.

Are first-trimester screening markers altered in assisted reproductive technologies pregnancies?

PURPOSE OF REVIEW: To review the current literature on first-trimester screening with respect to specific issues for assisted reproductive technologies (ARTs) singleton and twin pregnancies. RECENT FINDINGS: A number of different first-trimester sonographic and biochemical markers have been validated in first-trimester screening for trisomy 21. Among sonographic markers, measurement of fetal nuchal translucency is the most investigated and least affected screening method in ART pregnancies, achieving comparable results in singletons and twins compared with spontaneous conceptions. The small deviation of nuchal translucency thickness observed in ART singletons did not influence overall screening performance, including the number of false-positive results. First-trimester maternal serum free ß-human chorionic gonadotropin and pregnancy-associated plasma protein-A levels are more obviously altered in assisted conceptions and carry the risk of higher false-positive rates if not adjusted accordingly. The reason behind the alterations is currently not quite explored, but might be attributed to infertility and a higher incidence of placental disorders rather than to the use of ART. In twin pregnancies, chorionicity is an important confounding variable with evident impact on nuchal translucency measurements and maternal biochemistry, but both issues have not been sufficiently investigated in ART twins so far. SUMMARY: First-trimester measurement of fetal nuchal translucency in singleton and twin gestations is associated with similar screening results when compared with spontaneous conception. Adjustments for the mode of conception are required if maternal serum biochemistry is included in the screening algorithm. Further studies on assisted conception twins are essential to permit more conclusive results on this issue.

Candidates for the determination of antithrombin activity in pregnant women.

BACKGROUND: Some women exhibit a gradual decrease in antithrombin activity until the time of delivery, with antithrombin activity reaching <65% of the normal level (pregnancy-induced antithrombin deficiency, PIATD). However, the clinical features of such women are not well understood and are unfamiliar to many obstetricians. FINDINGS: PIATD is more likely to occur as the number of fetuses increases (approx. 1.0%, 10%, and 40% for singleton, twin, and triplet pregnancies, respectively) and in women with hypertension, isolated proteinuria and/or edema. However, normotensive women account for 60% of women with PIATD. Antithrombin can escape from the blood into the interstitial space. Women with PIATD suffer from a decreased plasma volume and are more likely to develop liver dysfunction, irrespective of the presence or absence of hypertension. Because antithrombin activity continues to decrease until the time of delivery in women with PIATD, women with unrecognized PIATD may be identified as patients with so-called "acute fatty liver of pregnancy" if delivery is delayed. CONCLUSION: Knowledge of AT activity in obstetrical practice may improve management of pregnant women. The determination of AT activity should be considered in women with multifetal pregnancies, hypertension, isolated proteinuria and/or edema.

Clinical indications for abnormal early gestational 50-g glucose tolerance testing.

Providers occasionally screen women thought to be at particularly increased risk of gestational diabetes mellitus (GDM) with a first- or second-trimester ("early") glucose tolerance test (GTT). We sought to describe how the frequency of abnormal early GTT varies by indication for testing. This is a retrospective cohort study of women receiving prenatal care in our clinic who underwent a 50-g GTT at less than 24 weeks between 2003 and 2006. Three hundred five women received an early GTT. The most common indications for early screening were obesity (53%), family history of diabetes (15%), prior history of GDM (10%), and multifetal gestation (5%). The frequency of abnormal testing in patients with multifetal gestations and a personal history of GDM was higher than in those undergoing early testing because of obesity. The frequency of abnormal early GTT varies by indication for testing. These data may be used in the allocation of health care resources.

Micronutrients in Multiple Pregnancies-The Knowns and Unknowns: A Systematic Review.

Maternal diet and nutritional status are of key importance with regard to the short- and long-term health outcomes of both the mother and the fetus. Multiple pregnancies are a special phenomenon in the context of nutrition. The presence of more than one fetus may lead to increased metabolic requirements and a faster depletion of maternal macro- and micro- nutrient reserves than in a singleton pregnancy. The aim of this systematic review was to gather available knowledge on the supply and needs of mothers with multiple pregnancies in terms of micronutrients and the epidemiology of deficiencies in that population. It was constructed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA). The authors conducted a systematic literature search with the use of three databases: PubMed/MEDLINE, Scopus and Embase. The last search was run on the 18 October 2020 and identified 1379 articles. Finally, 12 articles and 1 series of publications met the inclusion criteria. Based on the retrieved studies, it may be concluded that women with multiple pregnancies might be at risk of vitamin D and iron deficiencies. With regard to other microelements, the evidence is either inconsistent, scarce or absent. Further in-depth prospective and population studies are necessary to determine if nutritional recommendations addressed to pregnant women require adjustments in cases of multiple gestations.

Effect of changes in renal circulation on serum uric acid levels in women with twin pregnancy.

OBJECTIVE: We examined the relationship between serum uric acid levels and changes in renal circulation in women with twin pregnancy compared with those in women with singleton pregnancy. METHODS: The Doppler waveforms of the bilateral maternal main renal arteries were obtained from 15 women at 37-38 weeks of nonpreeclamptic twin pregnancy and 16 healthy women at the same gestational age of singleton pregnancy. The resistance index (RI), pulsatility index (PI), and acceleration time were determined. RESULTS: The mean serum uric acid level in the twin pregnancy group was significantly higher than that in the singleton pregnancy group (5.0 ± 0.9 vs. 3.7 ± 0.6 mg/dl, P < 0.01). Although there were no significant differences in the RI or PI levels between the singleton and twin pregnancy groups, the acceleration time in the twin pregnancy group was significantly prolonged compared with that in the singleton pregnancy group (82.2 ± 29 vs. 59.9 ± 17 ms, P = 0.01). There was a significant correlation between serum uric acid levels and acceleration times (r(2) = 0.55, P < 0.01). CONCLUSION: The changes in renal circulation may be one of the possible mechanisms leading to hyperuricemia in women with twin pregnancies.

Plasma adrenomedullin levels during multiple pregnancy.

BACKGROUND: To estimate the normal level of adrenomedullin (AM) during multiple pregnancy. METHODS: The study population consisted of 5 women with normal cycles, 130 women with normal pregnancy between 6 and 40 weeks of gestation, 93 women with twin pregnancy and 42 women with triplet pregnancy. RESULTS: Total AM concentration in the first trimester (13.7 +/- 0.58 fmol/ml), second trimester (26.8 +/- 1.13 fmol/ml) and third trimester (37.8 +/- 1.32 fmol/ml) in pregnant women was significantly higher than that in nonpregnant women (8.0 +/- 0.71 fmol/ml). In each trimester, the maternal plasma concentrations of triplet-pregnant women were significantly higher than in twin and singleton-pregnant women. Umbilical venous AM levels (29.9 +/- 2.63 fmol/ml) were higher than umbilical arterial AM (20.2 +/- 2.04 fmol/ml). CONCLUSION: Since alterations in the AM concentration in maternal plasma may mediate compensatory vascular responses in the uterine circulation, it might be useful to know the normal level of AM during multiple pregnancy in order to detect abnormalities during multiple pregnancy.

Is it useful to measure C-reactive protein and leukocytes in patients with prelabor rupture of membranes?

Neonatal infection is the main complication of prelabor rupture of membranes (PROM). We studied the accuracy of measuring C-reactive protein (CRP) and leukocytes in maternal serum to predict neonatal infection. We performed a retrospective cohort study in two hospitals in the Netherlands between 2003 and 2006. We included consecutive women hospitalized for PROM. In both hospitals, CRP and leukocytes were measured routinely in maternal serum every 2 days until delivery. End points considered were clinical neonatal infection and proven neonatal sepsis. The accuracy of CRP and leukocytes was assessed using receiver operating characteristic (ROC) analysis. We included 299 women with PROM, 12 of whom had a twin pregnancy. Gestational age at inclusion varied between 26 weeks and 0 days and 41 weeks and 5 days with a median of 37 weeks and 3 days. In 47 women (16%), the neonate developed a clinical infection. The areas under the ROC curve of CRP and leukocytes in the prediction of clinical neonatal infection were 0.61 and 0.62, respectively. Of the 47 infected neonates, six neonates (2%) had a proven neonatal sepsis. In the mothers of these septic neonates, maternal CRP did not rise above 50 mg/L and leukocyte values varied between 9.8 and 25.8 x 10 (9)/L. In women with PROM, CRP and leukocytes should not be measured routinely.

The effect of a 'vanishing twin' on biochemical and ultrasound first trimester screening markers for Down's syndrome in pregnancies conceived by assisted reproductive technology.

BACKGROUND: Previous studies have found that 1 in 10 in vitro fertilization (IVF) singletons originates from a twin gestation. First trimester Down's syndrome screening markers are altered in assisted reproductive techniques (ART) pregnancies compared with spontaneously conceived pregnancies. The presence of a perished embryo may further complicate prenatal screening among women pregnant after ART. The aim of this study was to assess the impact of a 'vanishing twin' on first trimester combined biochemical and ultrasound screening in pregnancies conceived after IVF and intracytoplasmatic sperm injection. METHODS: From a national prospective cohort study concerning first trimester combined screening among women pregnant after ART, 56 cases of pregnancies with a vanishing twin were identified. As control group 897 cases of ART singleton pregnancies were used. All women completed a first trimester combined ultrasound and biochemical screening programme comprising serum PAPP-A and free beta-hCG together with nuchal translucency (NT) measurement. RESULTS: There were no significant differences in geometric mean MoM free beta-hCG and PAPP-A between pregnancies with an early (gestational week <9, EVT) or late vanishing twin (gestational week 9-13, LVT) or singleton pregnancies (0.98, 1.13 and 0.95 for free beta-hCG and 0.84, 0.80 and 0.74 for PAPP-A, respectively). Likewise, no difference was seen for NT measurements. The gestational age at the time of blood sampling and NT scan was similar for the three groups. The proportion of EVT pregnancies with a PAPP-A and free beta-hCG log(10)MoM value below the 5th%iles and above the 95th%iles of the value in the singleton pregnancies were 4.3%, 4.3%, 6.4% and 8.5%, respectively, which did not constitute a significant difference from singletons. The corresponding values for LVT pregnancies were 0%, 22.2%, 0% and 11.1%, respectively; however, these numbers were too small to allow for statistical calculations. CONCLUSIONS: First trimester biochemical screening markers in women pregnant after ART, and with a vanished twin diagnosed at early ultrasound, do not differ from those of other ART singleton pregnancies. In cases where the fetal demise was first diagnosed at the time of the NT scan, it is doubtful whether the serum risk assessment is as precise as it is in singleton ART pregnancies. No difference was seen for NT measurements.

Follicle and hormone dynamics in single versus double ovulating heifers.

Follicles > or = 5 mm were ablated at 4 day post-ovulation in heifers to induce a follicular wave, and prostaglandin F(2alpha) was given at day 6 to increase the incidence of double ovulations. Follicle diameters and plasma hormone concentrations were compared between single ovulators (n=12) and double ovulators (n=8). In double ovulators, the interval from follicle deviation to the peak of the pre-ovulatory LH surge was shorter (1.9+/-0.2 vs 2.5+/-0.2 days; P<0.02) and diameter of the largest pre-ovulatory follicle was smaller (12.2+/-0.5 vs 13.3+/-0.3 mm; P<0.02). The LH concentrations of the pre-ovulatory surge did not differ between single and double ovulators for 24 h on each side of the peak. When data were normalised to LH peak, the peak of the pre-ovulatory FSH and oestradiol (E(2)) surges occurred in synchrony with the peak of LH surge for both groups. Concentration of FSH for 24 h on each side of the peak showed a group effect (P<0.0001) from lower concentration in the double ovulators. A group-by-hour interaction (P<0.008) for E(2) reflected greater concentration in the double ovulators before and at the peak. Results indicated that two pre-ovulatory follicles resulted in an earlier and greater E(2) increase, leading to lower FSH concentration, an earlier LH surge, and ovulation at a smaller diameter. In conclusion, the difference in hormone concentrations during the pre-ovulatory period was an effect rather than a cause of double ovulations.

First-trimester biochemistry and outcomes in twin pregnancy.

OBJECTIVE: To examine the relationship between levels of first-trimester serum analytes used in aneuploidy risk assessment and obstetric outcomes in twin pregnancy. STUDY DESIGN: Twin pregnancies undergoing first-trimester risk assessment from 2003 to 2005 were identified. Pregnancy-associated plasma protein A (PAPP-A) and free beta-human chorionic gonadotropin (beta-hCG) were measured at 9-14 weeks. The association between extreme biochemical values (< 5th and > 95th percentile) and adverse outcomes was examined. Fisher's exact test and Mann-Whitney U were used for comparison. RESULTS: A total of 326 pregnancies were included. Median maternal age was 35 years. Median gestational age at delivery was 36 weeks. There were no significant associations between extreme free beta-hCG or high PAPP-A values and the rates of any adverse outcomes. Low PAPP-A (< 0.52 multiples of the median) was associated with higher rates of discordant growth (50% vs. 13%; p = 0.001) and hypertensive disorders of pregnancy (41.2% vs. 15.5%, p = 0.01). CONCLUSION: In twin pregnancies, low PAPP-A is associated with discordant growth and hypertensive disorders.

Circulating electrolytes in the bloodstream of transition Sarda goats make the difference in body fluid distribution between single vs. twin gestation.

Health of transition goats can be explored through the assessment of the metabolic profile. Selected circulating parameters of clinical importance may be used for indicating homeostasis perturbations during the transition period. The present study aimed to characterize the metabolic profile of transition dairy goats raised under a pasture-based system to determine whether the conceptus number (single vs. twin gestation) influences circulating concentrations of different parameters in the bloodstream, including nutrient- and fluid-related metabolites for health assessment. Sarda dairy goats diagnosed for single (n = 5) or twin gestation (n = 6) were selected out of a flock of 156 heads and sampled for blood weekly, throughout one month before and one month after kidding. Significantly (p < .01), differences in blood serum metabolite concentrations before and after birthing were observed in both groups of animals, as to glucose (Glu), total cholesterol (TC) and triglycerides (TG), total protein (TP) and Urea. Circulating creatinine (Crea) turned out to differ significantly (p < .01) between single vs. twin kidding does. Significant correlations (p < .001) between groups of circulating electrolytes (Na, Chloride, Mg, K) were also observed and this datum was assumed to change following the different distribution of fluids in the body of the doe, in the last third of gestation, at birthing and during early lactation, respectively. Interestingly, electrolyte levels in this trial displayed different concentrations in the bloodstream according to physiological stage and kid numbers.

Circulating angiogenic factors in singleton vs multiple-gestation pregnancies.

OBJECTIVE: Placental soluble fms-like tyrosine kinase-1 may contribute to the pathogenesis of preeclampsia. Here we describe alterations in serum angiogenic factor levels in women with multiple gestation pregnancies, a major preeclampsia risk factor. STUDY DESIGN: We collected serial serum specimens from 101 pregnant women at high preeclampsia risk between 22 and 36 weeks' gestation. Soluble fms-like tyrosine kinase-1 and placental growth factor were measured by enzyme-linked immunosorbent assay. Women who had preeclampsia or gestational hypertension develop were excluded. RESULTS: Maternal soluble fms-like tyrosine kinase-1 was higher in multiple gestation (n = 20) compared with high-risk singleton (n = 81) pregnancies for each gestational age range examined. Maternal placental growth factor was significantly higher in multiple vs high-risk singletons before 31 weeks' gestation, whereas the soluble fms-like tyrosine kinase-1/placental growth factor ratio was higher in multiple vs high-risk singletons after 27 weeks. CONCLUSION: Alterations in circulating angiogenic factors are present in women with multiple gestations and may contribute to higher preeclampsia risk in this population.

Assessment of the predictive value of serum progesterone levels on early pregnancy prognosis in spontaneous twin gestations: a prospective study.

OBJECTIVES: The aim of this study was to assess the predictive value of serum progesterone levels in early pregnancy prognosis in spontaneous dichorionic-diamniotic twin gestations. STUDY DESIGN: This study was carried out among 38 spontaneous dichorionic-diamniotic twin gestations between January 2003 and June 2005 in the Department of Obstetrics and Gynaecology at the Gulhane Military Medical Academy. Serum progesterone levels were measured at 7 and 10 weeks' gestation and pregnancies were followed until 14 gestational weeks by ultrasound examination. RESULTS: We found that a progesterone level of 58 nmol/l in the 7th gestational week and of 51 ng/ml at 10 gestational weeks has a predictive value for viable intrauterine twin pregnancies with 83% sensitivity and 69% specificity and 83% sensitivity and 84% specificity, respectively. CONCLUSION: Progesterone levels in the early gestational weeks may be a biochemical marker for the prediction of a twin pregnancy outcome and may reduce the number of ultrasound examinations.

First-trimester risk assessment for trisomies 21 and 18 in twin pregnancy.

OBJECTIVE: Our objective was to describe performance of first-trimester combined risk assessment in twin pregnancies. STUDY DESIGN: Twin pregnancies that underwent risk assessment in our ultrasound unit from 2003-2006 were included. Adjusted risks for trisomies 21 and 18 that were based on age, nuchal translucency (NT), and biochemistry were provided for each twin. Detection rates for Down syndrome and trisomy 18 were calculated for age/NT, and age/NT/biochemistry at a screen-positive rate of 5% of pregnancies. RESULTS: Five hundred thirty-five pregnancies were included. Median maternal age was 34 years, with 47% of women > or = 35 years old. There were 7 fetuses in 6 dichorionic pregnancies with Down syndrome and 3 fetuses in 3 pregnancies with trisomy 18. For a 5% false-positive rate, age/NT identified 83.3% of Down syndrome and 66.7% of Trisomy 18 pregnancies. Adding biochemistry resulted in 100% detection rates for both conditions. CONCLUSION: The addition of biochemistry may enhance first-trimester risk assessment in twin pregnancies. Further studies with larger numbers of affected pregnancies are needed.