Sexual behaviour of women with twin pregnancies.

It has been assumed that sexual activity during pregnancy would lead to an increased risk for miscarriage and other complications of pregnancy. Various studies showed no association of sexual behavior and pregnancy complications in single pregnancies. The aim of our study was to evaluate changes in sexual activity in women with twin pregnancies and whether a higher frequency of sexual intercourse was associated with an increased risk for pregnancy complications. We report on 50 women with twin pregnancies who answered a questionnaire on sexual behavior during pregnancy. At the time of delivery, patients were aged 31.0 +/- 4.8 years. All women reported to have had sexual intercourse during pregnancy. In contrast to the first trimester in the vast majority of patients (41/50, 82.0%) the coital frequency decreased in the last month of pregnancy. Patients who had become pregnant after in-vitro fertilization were significantly less likely to have regular sexual intercourse than patients after spontaneous conception during early pregnancy (p = .002). No statistical significances were found when the rates of preterm delivery before the 37th gestational week were compared to the frequencies of sexual intercourse during early pregnancy and during late pregnancy (p >.05). In conclusion, our study demonstrates a decrease in frequency of sexual intercourse from early to late pregnancy in the specific collective of women with twin pregnancies, especially in women after in-vitro fertilization. There was no association between sexual activity and preterm delivery.

Prediction of spontaneous preterm delivery in twin pregnancies by cervical length at mid-gestation.

The objective of our study was to evaluate the correlation of the cervical length at 20-25 weeks of gestation with the incidence of spontaneous preterm delivery in twins in a country with a high incidence of preterm delivery compared to other European countries. Cervical length was measured in 262 consecutive patients. Previous preterm delivery before 34 weeks of gestation, chorionicity, maternal age, body-mass-index, smoking habit and parity were recorded as risk factors for preterm delivery. Women who were symptomatic at 20-25 weeks and who delivered because of other reasons than spontaneous labour and preterm rupture of membranes or at term were excluded. The primary outcome was incidence of preterm birth before 34 weeks. Two hundred and twenty-three patients were analyzed. Thirty-two (14%) delivered before 34 weeks. There was a significant correlation between cervical length of less than 25 mm and spontaneous delivery before 34 weeks (50% vs. 13%, p = .007). In addition, logistic regression analysis found cervical length to be the only significant predictor of spontaneous delivery before 34 weeks (OR 1.084; 95% CI 1.015; 1.159; p = .017). We conclude that the risk of severe preterm delivery in twins is high. Cervical length at mid-gestation was the only predictor of delivery before 34 weeks.

In utero tractography of fetal white matter development.

Diffusion tensor imaging (DTI) and tractography are noninvasive tools that enable the study of three-dimensional diffusion characteristics and their molecular, cellular, and microstructural correlates in the human brain. To date, these techniques have mainly been limited to postnatal MR studies of premature infants and newborns. The primary aim of this cross-sectional study was to assess the potential of in utero DTI and tractography to visualize the main projection and commissural pathways in 40 living, non-sedated human fetuses between 18 and 37 gestational weeks (GW) of age, with no structural brain pathologies. During a mean time of 1 min and 49 s, an axial, single-shot, echo planar DT sequence, with 32 diffusion gradient encoding directions and a reconstructed voxel size of 1.44 mm/1.45 mm/4.5 mm, was acquired. Most (90%) of the fetuses were imaged in the cephalic presentation. In 40% of examined fetuses, DTI measurements were robust enough to successfully calculate and visualize bilateral, craniocaudally oriented (mainly sensorimotor), and callosal trajectories in utero. Furthermore, fiber lengths, ADC, FA, and eigenvalues (lambda(1), lambda(2) and lambda(3)) were determined at different anatomically defined areas. FA values and the axial eigenvalue (lambda(1)) showed a characteristic distribution, with the highest values for the splenium, followed by the genu, the right, and the left posterior limb of the internal capsule. The right-sided sensorimotor trajectories were found to be significantly longer than on the left side (p=0.007), reflecting higher right-sided lambda(1) values (14 cases vs. 9 cases). Based on the good correlation of these initial in utero tractography results with prior documented postmortem and ex utero DTI data, this new imaging technique promises new insights into the normal and pathological development of the unborn child.

Psychological reactions in women undergoing fetal magnetic resonance imaging.

OBJECTIVE: To investigate women's psychological reactions when undergoing fetal magnetic resonance imaging (MRI), and to estimate whether certain groups, based on clinical and sociodemographic variables, differ in their subjective experiences with fetal MRI and in their anxiety levels related to the scanning procedure. METHODS: This study is a prospective cohort investigation of 62 women before and immediately after fetal MRI. Anxiety levels and subjective experiences were measured by questionnaires. Groups based on clinical and sociodemographic variables were compared with regard to anxiety levels and to the scores on the Prescan and Postscan Imaging Distress Questionnaire. RESULTS: Anxiety scores before fetal MRI were 8.8 points higher than those of the female, nonclinical, norm population (P<.001). The severity of the referral diagnosis showed a linearly increasing effect on anxiety level before MRI (weighted linear term: F1,59=5.325, P=.025). Magnetic resonance imaging was experienced as unpleasant by 33.9% (95% confidence interval [CI] 21.2-46.6%) and as hardly bearable by 4.8% (95% CI 0-17.5%) of the women. Physical restraint (49.9%, 95% CI 37.4-62.4%), noise level (53.2%, 95% CI 40.7-65.7%), anxiety for the infant (53.2%, 95% CI 40.7-65.7%), and the duration of the examination (51.6%, 95% CI 39.1-64.1%) were major distressing factors. CONCLUSION: Women who undergo fetal magnetic resonance imaging experience considerable distress, especially those with poor fetal prognoses. Ongoing technical developments, such as a reduction of noise, shortening the duration of the MRI, and a more comfortable position in open MRI machines, may have the potential to improve the subjective experiences of women during fetal MRI. LEVEL OF EVIDENCE: III.

[Prematurity in multiple pregnancies]. / Frühgeburtlichkeit bei Mehrlingsschwangerschaften.

At present, 1.5% of all pregnancies are twin pregnancies, but twin pregnancies account for 25% of all premature infants. The chorionicity plays an important role: the risk of preterm birth before 32 weeks is 5.5% in dichorial twins and almost double (9%) in monochorial twins. The rate of intrauterine growth restriction and also the perinatal mortality are twice as high in monochorial compared to dichorial twins. In cases of imminent preterm labour, tocolysis is recommended until lung maturity has been achieved. The preferred drugs, are oxytocin antagonists because of the increased cardiorespiratory strain in multiple pregnancies. Prophylactic bed rest and 'home uterine activity monitoring' have not been shown to improve the outcome, and a recent review (2005) demonstrated a twofold increase in preterm labour after cervical cerclage. In two large placebo-controlled studies, the rate of preterm delivery in high-risk singleton pregnancies was significantly reduced by the regular application of progesterone. A potential effect on multiple pregnancies is yet to be shown.

MRI of normal fetal brain development.

Normal fetal brain maturation can be studied by in vivo magnetic resonance imaging (MRI) from the 18th gestational week (GW) to term, and relies primarily on T2-weighted and diffusion-weighted (DW) sequences. These maturational changes must be interpreted with a knowledge of the histological background and the temporal course of the respective developmental steps. In addition, MR presentation of developing and transient structures must be considered. Signal changes associated with maturational processes can mainly be ascribed to the following changes in tissue composition and organization, which occur at the histological level: (1) a decrease in water content and increasing cell-density can be recognized as a shortening of T1- and T2-relaxation times, leading to increased T1-weighted and decreased T2-weighted intensity, respectively; (2) the arrangement of microanatomical structures to create a symmetrical or asymmetrical environment, leading to structural differences that may be demonstrated by DW-anisotropy; (3) changes in non-structural qualities, such as the onset of a membrane potential in premyelinating axons. The latter process also influences the appearance of a structure on DW sequences. Thus, we will review the in vivo MR appearance of different maturational states of the fetal brain and relate these maturational states to anatomical, histological, and in vitro MRI data. Then, the development of the cerebral cortex, white matter, temporal lobe, and cerebellum will be reviewed, and the MR appearance of transient structures of the fetal brain will be shown. Emphasis will be placed on the appearance of the different structures with the various sequences. In addition, the possible utility of dynamic fetal sequences in assessing spontaneous fetal movements is discussed.

First-trimester nuchal translucency screening in pregnant women who subsequently developed gestational diabetes.

OBJECTIVE: To compare the nuchal translucency (NT) thickness at 11-14 weeks of gestation in women who will later develop gestational diabetes mellitus (GDM) with that of women with normal glucose tolerance (NGT) in the second trimester of pregnancy. METHODS: Four hundred sixty-four women underwent NT screening at 11-14 weeks of gestation according to the standards of the Fetal Medicine Foundation. They all underwent an oral glucose tolerance test (OGTT) between 24 and 28 weeks. RESULTS: Women with GDM (n = 135) were significantly older (34.0 years [+/-4.8] vs 29.4 years [+/-5.2]; P < .001), had a significantly higher body mass index (BMI) (28.2 kg/m2 [+/-6.0] vs 24.4 [+/-5.0]; P < .001), and had a significantly higher serum concentration of hemoglobin A1c (HbA1c) at the time of the NT measurement (5.38% [+/-0.6] vs 4.95% [+/-0.4]; P < .001] than women with NGT (n = 329). There is no significant difference in the NT measurement at 11 to 14 weeks of gestation between women with GDM and NGT after correction for crown rump length (CRL) (r = -.08, P = .45). We performed multiple linear regression analysis with NT as the dependent variable, and BMI, maternal age, CRL, and GDM/NGT as independent variables. CRL (P < .001) was significantly related to the NT measurement, whereas GDM/NGT, BMI, and maternal age were not. CONCLUSION: As no significant difference in the NT measurement between women with GDM and NGT was observed, the risk estimation for chromosomal abnormality derived from the maternal age and NT measurement can also be used in women with glucose disorders.

[Screening of chromosome anomalies during the first trimester]. / Screening auf Chromosomenanomalien im ersten Trimenon.

In view of today's knowledge, it is evident that a very efficient screening for chromosome anomalies can be carried out during the first trimester. Prospective studies of a total of 200,868 pregnancies-among them 871 fetuses with trisomy 21-have shown that measuring the nuchal transparency can identify 76.8% of fetuses with trisomy 21, with a false-positive rate of 4.2%. If the measurement of nuchal transparency is combined with that of the maternal serum concentrations of free human beta-choriogonadotropin and pregnancy-associated plasma A, the detection rate is 87.0% with a false-positive rate of 5% (prospective studies of altogether 44,630 pregnancies with 215 fetuses suffering from trisomy 21). At present, further signs of Down syndrome in the first trimester are being investigated, such as the missing fetal nasal bone, the maxilla and the blood flow pattern in the ductus venosus. Well-known signs of trisomy 13 and 18, which are already visible in the first trimester, are megacystis, omphalocele, polydactyly and holoprosencephaly. Most pregnant women prefer being screened during the first instead of the second trimester. Therefore every expectant mother should be offered an appropriate examination during the first trimester. It is essential for the effectiveness of the screening that the examiners be suitably trained and that the results of the ultrasound and laboratory examinations be subjected to a regular external quality control. In Austria, there is a general consent to follow the guidelines of the Fetal Medicine Foundation.

Maternal cardiac function during pregnancy at high altitude.

OBJECTIVE: To investigate the maternal cardiovascular adaptation in pregnancy at high altitude, compared with that at sea level. DESIGN: Cross sectional study. SETTING: Two maternity units providing routine antenatal care: one at 4370 m above sea level (Cerro de Pasco, Peru) and one at sea level (Lima, Peru). POPULATION: We examined 175 pregnant women at 5-41 weeks of gestation and 16 non-pregnant controls resident at high altitude and 132 pregnant women and 18 non-pregnant controls at sea level. METHODS: Two-dimensional and M-mode echocardiography of the left ventricle. MAIN OUTCOME MEASURES: Maternal cardiac output and left ventricular longitudinal and transverse systolic function indices. RESULTS: Pregnancy at high altitude, compared with sea level, is associated with 11% lower birthweight and 31% lower maternal cardiac output, due to 15% lower stroke volume and 11% lower heart rate. The lower stroke volume was due to a lower preload and impaired longitudinal and transverse left ventricular systolic function. Mean arterial pressure was about 8% lower during pregnancy at high altitude versus sea level. Pregnant women at high altitude failed to expand their intravascular space to the same extent as the sea level group: cardiac output increased by 17%, left atrial diameter by 12% and end-diastolic diameter by 1% at high altitude versus 41%, 25% and 5%, respectively, at sea level. CONCLUSIONS: Pregnancy at high altitude, compared with sea level, is characterised by lower cardiac output due to lower heart rate and lower stroke volume and reduced expansion of the maternal intravascular space compared with the non-pregnant state.

Pregnancy at high altitude: a hyperviscosity state.

BACKGROUND: Pregnancy at high altitude has been associated with intrauterine growth restriction and preeclampsia. These conditions, at sea level, have been linked to increased hematocrit and blood viscosity. The aim of this study was to investigate the effect of high altitude on maternal hemorheology. METHODS: This was a cross-sectional study. We examined 94 pregnant women at 10-38 weeks of gestation resident at high altitude (4370 m above sea level) and 75 at sea level, and 24 and 17 nonpregnant women at each altitude, respectively. Blood and plasma viscosity, hematocrit, plasma fibrinogen, albumin and total protein concentrations were determined in blood samples obtained after an overnight period of fasting. RESULTS: Pregnancy at high altitude, compared to sea level, is characterized by higher hematocrit, blood viscosity (at high shear rate), plasma viscosity, total protein and fibrinogen concentrations (25%, 38%, 7%, 13.3% and 25%, respectively) and 6% lower albumin concentration. Nonpregnant women at high altitude, compared to sea level, had higher hematocrits, blood viscosity, plasma viscosity, total protein and fibrinogen concentrations (25%, 55%, 18%, 26% and 98%, respectively) and 13% lower albumin concentration. CONCLUSION: Pregnancy at high altitude compared to sea level is characterized by increased blood viscosity as a result of increased hematocrit and plasma viscosity.

Maternal cardiac function in twin pregnancy.

OBJECTIVE: To investigate maternal cardiac function in twin pregnancy. METHODS: We conducted a cross-sectional study of 119 pregnant women with twin pregnancies at 10-40 weeks' gestation. Two-dimensional and M-mode echocardiography of the left ventricle was performed in the left lateral decubitus position to assess left ventricular longitudinal and transverse systolic function. The measurements were compared with those obtained from 128 women with singleton pregnancies previously reported. RESULTS: In twin pregnancies, compared with singletons, maternal cardiac output was greater by 20% (P <.001), because of a greater stroke volume (15%, P <.001) and heart rate (3.5%; P =.04). Furthermore, in women with twins there were greater left ventricular end-diastolic and left ventricular end-systolic dimensions, left ventricular mass (13.5%; P <.001), fractional shortening (3%; P =.04), and ejection fraction (2.5%; P =.04). Mean arterial pressure and global time to shortening in women with twins, compared with singletons, were less in the first trimester by approximately 2%, but after midpregnancy they increased progressively, so that at term the measurements were greater by 3% and 5.7%, respectively (P =.03). Conversely, long axis shortening in women with twins, compared with singletons, was greater in the first trimester by approximately 6.5%, but at term it was 3% less (P =.01). Twin pregnancies that subsequently developed preeclampsia had a hemodynamic profile similar to the rest of the twin population. CONCLUSION: Twin pregnancy is characterized by an even more hyperdynamic circulation than singleton pregnancy. Left ventricle longitudinal systolic function and mean arterial pressure are more abruptly affected after 20 weeks compared with singleton pregnancies.

Maternal electrolyte and liver function changes during pregnancy at high altitude.

BACKGROUND: High-altitude (HA) hypoxia leads to profound cardiovascular, respiratory and electrolyte changes, and pregnancy at HA has been associated with increased incidence of preeclampsia and intrauterine growth restriction. OBJECTIVE: To examine the effect of high altitude on maternal serum electrolytes and liver enzymes. DESIGN: Cross-sectional study of 77 pregnant women at 6-40 weeks of gestation resident at HA (4370 m above sea level) and 80 at sea level (SL) and 13 and 15 nonpregnant women at each altitude, respectively. Serum electrolytes (sodium, potassium, calcium and phosphate), creatinine, bilirubin and liver enzymes (alkaline phosphatase (ALP), aspartate transaminase (AST) and gamma-glutamyl transferase (gamma-GT)) were measured. RESULTS: Pregnancy at HA, compared to SL, was associated with higher serum osmolality (0.4%), sodium (0.7%), creatinine (14%) and phosphate (5%) concentrations and lower potassium (10%) concentration. Calcium and albumin-corrected calcium concentrations were higher at HA compared to SL in nonpregnant women (8%), with no difference in pregnant women. AST, gamma-GT and ALP concentrations were not significantly different between HA and SL, neither in pregnant nor in nonpregnant women. AST and gamma-GT were lower in pregnant compared to nonpregnant women (30%) at HA, whereas the difference was not significant at SL. Total bilirubin concentrations were higher at HA compared to SL by about 25% both in pregnant and in nonpregnant women, the difference reaching statistical significance only in the pregnant group. CONCLUSIONS: Pregnancy at HA is associated with increased osmolality, sodium, creatinine, calcium, phosphate and total bilirubin concentrations. Liver enzyme activities are similar to SL.

Maternal serum insulin-like growth factor binding protein-1 in pregnancy at high altitude.

OBJECTIVE: To investigate the effect of environmental hypoxia at 4300-m altitude on the maternal serum concentration of insulin-like growth factor binding protein-1 (IGFBP-1). METHODS: We conducted a cross-sectional study of 108 pregnant women in Peru, 62 from high altitude (4300 m, 14100 ft) and 46 from sea level at 14-42 weeks' gestation. For comparison, 20 healthy nonpregnant women (ten from high altitude and ten from sea level) were also examined. Total and nonphosphorylated IGFBP-1 were measured in maternal serum. RESULTS: Both total and nonphosphorylated IGFBP-1 were higher at high altitude than at sea level in the pregnant groups (ratio = 1.28, P =.008, and ratio = 1.45, P =.003, respectively), and there was significant interaction between high altitude and sea level (P =.037 and P =.043, respectively). The threshold model showed that the difference became significant from 25 weeks' gestation onwards. CONCLUSION: Before 25 weeks of pregnancy, there was no significant difference in IGFBP-1 between women living at high or low altitude, suggesting that the increased IGFBP-1 at high altitude is unlikely to be related to inadequate trophoblast invasion resulting in placental hypoxia. In the second half of pregnancy, the maternal and fetal demands increase dramatically, and low atmospheric oxygen with resulting maternal systemic hypoxemic hypoxia may cause placental hypoxia. This stimulates increased production of IGFBP-1, which in turn restricts the insulin-like growth factor-mediated fetal growth as an adaptive mechanism to prevent worsening of the fetoplacental hypoxia.