Acute and chronic fetal hypoxia in monochorionic and dichorionic twins

OBJECTIVE: To assess the risk for acute and chronic fetal hypoxia in twin pregnancies. METHODS: We investigated 50 sets of twins (24-38 weeks' gestation, 660-3200 g birth weight) admitted consecutively to our neonatal intensive care unit. Seventy-six infants were appropriate for gestational age (AGA; tenth to 90th percentile), 20 were small for gestational age (SGA; below the tenth percentile), and four were large for gestational age (above the 90th percentile). Twenty-six singleton AGA term newborns served as controls. Umbilical arterial pH was used as a marker for acute and umbilical venous erythropoietin concentration for chronic fetal hypoxia. The results are given as median followed by quartiles. RESULTS: We identified 40 sets of diamniotic-dichorionic twins and ten sets of diamniotic-monochorionic twins with transplacental vascular shunts. In the second-born twin, umbilical arterial pH was lower (7.29, 7.23-7.33) than in the firstborn (7.31, 7.25-7.34) (P = .03), and the incidence of a low pH (less than 7.20) was higher (19 versus 11%). Two second-born twins and none of the firstborn twins had an umbilical arterial pH less than 7.05. In SGA twins, the erythropoietin concentration was elevated (34.8, 22.8-325 mU/mL) compared with that in AGA twins (16.2, 8.2-26.6 mU/mL) (P < .01). In AGA twins, erythropoietin concentration did not differ from that in AGA singleton newborns (19.6, 14.7-31.6 mU/mL). In 12 of 17 twin sets with weight discordancy greater than 15% and in all five twin sets with weight difference greater than 25%, erythropoietin concentration was higher in the smaller twin. The proportion of infants and of complete sets with elevated erythropoietin levels was higher (P < .01) in monochorionic than in dichorionic pregnancies. CONCLUSION: The second-born twin is at increased risk for acute birth asphyxia. Fetal growth restriction in twin pregnancies is associated with chronic fetal hypoxia. Monochorionic twins are at higher risk for chronic fetal hypoxia than are dichorionic twins.     

Multifetal pregnancy reduction: modification of the technique and analysis of the outcome

OBJECTIVE: To modify the technique of multifetal pregnancy reduction and to study the outcome of reduced twins in comparison with nonreduced twins and high-order multiple gestations. DESIGN: Prospective controlled study. SETTING: The Egyptian IVF-ET Center, Cairo. PATIENT(S): Seventy-five patients with high-order multiple pregnancies resulting from assisted reproduction. Controls were 40 nonreduced twin pregnancies and 22 high-order multiple gestations. INTERVENTION(S): Transvaginal ultrasonically guided multifetal pregnancy reduction was performed. The first 30 cases were done using KCl as a cardiotoxic agent. The modified technique was used for the last 45 cases at an earlier gestational age (approximately 7 weeks) by eliminating the use of KCI and by aspirating the embryonic parts. MAIN OUTCOME MEASURE(S): Miscarriage rate, gestational age at delivery, birth weight, and pregnancy complications. RESULT(S): Using the modified technique, the miscarriage rate was 8.8% and 41 patients delivered between 32 and 39 weeks of gestation (mean+/-SD, 36.9+/-2.45 weeks). The mean (+/-SD) birth weight was 2,450.51+/-235.44 g. The miscarriage rate, fetal wastage rate, mean gestational age, and mean birth weight were similar in reduced and nonreduced twins and were significantly better than in nonreduced triplets and quadruplets. CONCLUSION(S): The modified technique of multifetal pregnancy reduction significantly improved outcomes, which were similar to those of nonreduced twins resulting from assisted reproduction and significantly better than those of nonreduced triplets and quadruplets.     

Laboratory aid and ultrasonography in the diagnosis of appendicitis in children

The purpose of this study was to evaluate the relationship between the number of yolk sacs and amnionicity in monochorionic twin pregnancies scanned early in the first trimester. We retrospectively reviewed images of all monochorionic twins scanned between 6 and 9.5 weeks' gestation and with pathologic or sonographic confirmation of chorionicity-amnionicity. Each film was reviewed for the number of yolk sacs present, as well as for the gestational age at which the amniotic membrane was first visualized. Twenty monochorionic-diamniotic pregnancies and two monochorionic-monoamniotic pregnancies met the criteria for inclusion in the study. In diamniotic pregnancies scanned at less than 8 weeks' gestation, only the yolk sacs were identified; none of the dividing amniotic membranes were detected. Two yolk sacs were identified in all but one case. In this case, although one yolk sac was seen at 6 weeks, follow-up scanning at 8 weeks revealed two yolk sacs. In each of the monochorionic-monoamniotic twin pregnancies, one yolk sac was seen at 9 weeks and a single amnion encircled both embryos. We conclude that the sonographic identification of two yolk scas in monochorionic twins enables us to make the diagnosis of diamniotic twins early in the first trimester, before the amniotic membrane can be imaged. The presence of one yolk sac should prompt a follow-up ultrasonogram to assign amnionicity definitively.     

Lower risks of adverse outcome in twins conceived by artificial reproductive techniques compared with spontaneously conceived twins

The outcomes of twins conceived by 136 women after medical assistance (MA) such as ovulation induction with or without assisted reproductive techniques, and twins conceived spontaneously (SP) by 72 women were compared. All 208 women were monitored from < 20 weeks gestation; they all delivered at > or = 24 weeks gestation. The chorionicity of the placenta was diagnosed antenatally and confirmed after delivery. There were 10 perinatal deaths; the physical and neurological status of the remaining 406 infants was assessed at 1 year of corrected age. There were no differences in gestational age at birth, the birth weights of the larger and smaller twins, the birth weight discordance, or the incidence of life-threatening major malformations between groups. Adverse infant outcomes, such as death, cerebral palsy and mental retardation occurred in nine (3.3%) of 272 MA twins compared with 12 (8.3%) of 144 SP twins (P < 0.05). The placenta was monochorionic in only three (2.2%) of 136 MA twin pregnancies compared with 41 (57%) of 72 SP twin pregnancies (P < 0.001). Of the 21 infants with adverse outcomes, nine had monochorionic placentas. Thus, the risk of an adverse outcome was 2.8-fold higher (95% confidence interval (CI) 1.2-6.4) in monochorionic twins than in dichorionic twins (10 versus 3.7%; P < 0.05). There was no difference in the incidence of adverse infant outcomes between SP (4.8%) and MA (3.4%) twins with dichorionic placentas. These findings suggest that ovulation induction in itself was not associated with an adverse outcome of twin pregnancies. The lower frequency of monochorionic placentas in MA twins may have been responsible for the lower risk of an adverse outcome in MA twins.     

Maternal weight gain patterns and birth weight outcome in twin gestation

OBJECTIVE: To evaluate the association between maternal weight gain patterns, based on pregravid body mass index (BMI) and birth weight outcome in twins, and to make specific recommendations for maternal weight gain during twin gestation. METHODS: One hundred eighty-nine twin pregnancies were reviewed retrospectively. Weekly rates of maternal weight gain before 20 weeks, from 20 weeks to delivery, and for total gestation were calculated. Thresholds of weekly maternal weight gain were determined for underweight and normal-weight women. RESULTS: In underweight women, a higher weekly rate of gain before 20 weeks was associated with the birth of both twins weighing at least 2500 g (1.13 versus 0.70 lb/week, P = .017), when compared with mothers of at least one twin weighing less than 2500 g. A higher rate of weight gain from 20 weeks to delivery was associated with the delivery of twins weighing at least 2500 g in both underweight (1.92 versus 1.29 lb/week, P = .031) and normal weight (1.63 versus 1.29 lb/week, P = .046) women. No significant differences in weight gain patterns were found between overweight women delivering twins weighing less than 2500 g or at least 2500 g. A weekly rate of gain from 20 weeks' gestation to delivery of at least 1.75 lb/week in underweight women and at least 1.50 lb/week in normal-weight women was associated with the birth of both twins weighing at least 2500 g. After controlling for other potential determinants of birth weight, the threshold of 1.75 lb/week in underweight women showed a trend toward significance as an independent predictor of both twins weighing at least 2500 g (P = .06). CONCLUSION: Certain maternal weight gain patterns during twin pregnancy are associated with the birth of each twin weighing at least 2500 g. As with singletons, recommendations for maternal weight gain during twin pregnancy can be based on pregravid BMI.     

A comparison of sonographic growth curves of triplet and twin fetuses

Sonographic growth curves of 47 normal triplet pregnancies were compared with those of 71 uncomplicated twin gestations. Starting from the 25th week, the biparietal diameter in triplets was found to lag progressively compared with that of twins, reaching a mean difference of 2 weeks at 36 weeks gestation. Similarly, a significant difference was found between the femur length and head to abdomen circumference ratio growth curves of triplets and twins. It is concluded that as pregnancy continues from the 25th to the 36th gestational week, there is a significant delay in the growth patterns of normal triplet pregnancies compared with twin gestations.     

Liveborn twin with intrauterine death of one twin: report of two cases

Twin pregnancies carry a greater mortality and morbidity rate than singleton pregnancies. In case of an intrauterine fetal death (IUFD), the risk of mortality and morbidity of the surviving twin is increased. The pathogenesis is usually due to twin to twin transfusion. The donor twin is hypovolemic, anemic and often shows a growth retardation or even severe enough to cause an IUFD. The recipient twin is hypervolemic, polycythemic and weighs more than its co-twin. In this paper we reported two cases of liveborn twin complicated by an IUFD of its co-twin. Both cases were monochorionic twins. The first case was born at 29 weeks and 6 days of gestation, a male infant weighed 1054 g. His co-twin was stillborn and weighed 722 g. At birth the surviving infant showed respiratory distress syndrome (RDS), anemia and bilateral periventricular echogenicity (PVE). The second case was a female infant with a gestational age of 26 weeks and 2 days and weighed 850 g. Her stillborn co-twin weighed 804 g. Both twins showed signs of hydrops, and the liveborn infant had RDS, marked anemia (Hb 6 g/dl) and hypoalbuminemia. We will discuss the possible pathogenesis in our cases and also review some literature.     

Causes of perinatal mortality in twins

The author analyses perinatal mortality in 244 twin pregnancies. In 80% the twins' Apgare score at birth was 10 to 8 and neonatal mortality in this group 1.26%. The slightly asphyxial group (Apgar 7 to 4) comprised 62 (38.75%) twins and the neonatal mortality in this group was 14.51%. There were 20 (12.5%) severely asphyxial (Apgar 3 or less) twins, their neonatal mortality amounting to 80.0%. Out of 193 twins weighing at birth less than 2500 g, 45 (23.31%) died, while in the twins weighing more than 2500 g there was not a single death. The perinatal mortality of twins up to the 37th week of pregnancy amounted to 17.37% and from the 38th week of pregnancy to 1.22%. The mean duration of pregnancy in twins was 38.1 +/- 2 SD 6.3 weeks. The most frequent cause of death in twins has proved to be immaturity and asphyxia at birth, leading to the development of hyaline membranes (80.0%). Other causes were far less frequent. The author concludes that in the perinatal mortality of twins their vitality at birth (assessed by the Apgar score), birth weight, and the duration of pregnancy play an important role.     

Doppler velocimetry determined redistribution of fetal blood flow: correlation with growth restriction in diamniotic monochorionic and dizygotic twins

OBJECTIVE: Our purpose was to study fetal growth and blood flow distribution in diamniotic monochorionic compared with dizygotic (diamniotic dichorionic) twins by use of Doppler velocimetry of the umbilical artery and middle cerebral artery. STUDY DESIGN: Study candidates were divided into group A, consisting of 33 pairs (66 fetuses) of diamniotic monochorionic twins, and group B, 50 pairs (100 fetuses) of diamniotic dichorionic twins. Diamniotic monochorionic placentation was confirmed by microscopic placental examination for group A. Diamniotic dichorionic placentation was ensured for group B by selecting only twins with different-sex pairs (dizygotic twins). Targeted ultrasonography with biometry was performed in each twin, and Doppler recordings of the umbilical artery and middle cerebral artery were obtained. Waveforms were analyzed and the systolic/diastolic ratio, the resistance index, and a measure of blood flow redistribution (brain-sparing effect), the cerebral/placental ratio, was calculated for each fetus. Growth status at birth was assessed by the number of small-for-gestational-age infants (< or = 10th percentile), low-birth-weight infants (< or = 25th percentile), and percent of growth discordance between twins. Intertwin differences were assessed by delta values (value of larger twin minus value of smaller twin). RESULTS: Diamniotic monochorionic compared with dizygotic twins demonstrated a significantly greater probability of blood flow redistribution. For the study population as a whole, the brain-sparing effect was noted in 67% of small-for-gestational-age babies and only 7% of non-small-for-gestational-age infants (p < or = 0.001). For the diamniotic monochorionic pregnancies blood flow redistribution occurred in 6 of 10 small-for-gestational-age infants (60%) and 6 of 46 non-small-for-gestational-age infants (13%). In the diamniotic monochorionic group small-for-gestational-age compared with non-small-for-gestational-age infants were more likely to show blood flow redistribution, which was the result of significantly decreased resistance in the middle cerebral artery and significantly increased resistance in the umbilical artery. Small-for-gestational-age infants (< or = 10th percentile) occurred much less frequently in the dizygotic group. Two of two small-for-gestational-age infants in the dizygotic group showed blood flow redistribution. Although the extremes of birth weight were more common in the diamniotic monochorionic group, both groups had relatively large numbers of small babies with birth weights in the lower 25th percentile (50.0% for diamniotic monochorionic and 44.0% for dizygotic twins, not significant). However, 42.3% (11/26) of diamniotic monochorionic twins who were in the low-birth-weight group showed blood flow redistribution compared with only 3.3% (1/30) whose birth weights were > or = 25th percentile (p < or = 0.001). In the dizygotic twins 10% of lower-birth-weight infants redistributed blood flow compared with 1% in the higher-birth-weight group, a nonsignificant difference. Diamniotic monochorionic compared with dizygotic twins were delivered earlier (32.9 weeks vs 34.8 weeks, p < or = 0.001), were smaller (1832 gm vs 2304 gm, p < or = 0.001), showed higher birth weight discordance (29.8% vs 14%, p < or = 0.05), and had greater numbers (19.7% vs 2.3%, p < or = 0.01) of infants at < or = 10th percentile birth weight. CONCLUSIONS: Diamniotic monochorionic twins from the lower-birth-weight groups more often show blood flow redistribution compared with dizygotic twins of similar low birth weights. Placental vascular connections and the attendant hemodynamic changes in the fetuses of diamniotic monochorionic twins probably account for this difference. Brain-sparing events occur commonly without clinical twin transfusion syndrome in this group. These findings have implications for management.     

"Appearing twin": undercounting of multiple gestations on early first trimester sonograms

An important role of first trimester sonography is to determine whether a pregnancy is a singleton, twin, or higher order multiple gestation. We assessed how frequently sonography at 5.0-5.9 weeks undercounts multiple gestations. We identified all pregnancies at our institution since 1988 in which (1) an initial sonogram obtained at 5.0-5.9 weeks demonstrated at least a singleton intrauterine pregnancy and (2) a subsequent sonogram at 6.0 weeks or beyond demonstrated a living multiple gestation. Twenty-four (11%) of 213 dichorionic twin gestations were initially undercounted as singletons, as were six (86%) of seven monochorionic twin gestations. Among 105 higher order multiples, 17 (16%) were undercounted initially. All but one of the undercounted cases were scanned transvaginally. Undercounting occurred in both natural and assisted conceptions, and it occurred more frequently on sonograms obtained at 5.0-5.4 weeks than at 5.5-5.9 weeks (P = 0.02, Fisher's exact test). Prognosis for undercounted multiple gestations was similar to that of correctly counted ones with respect to several measures of pregnancy outcome, including the likelihood that all fetuses would be delivered liveborn, gestational age at birth, and birth weight (P > 0.20, all comparisons). In conclusion, transvaginal sonography at 5.0-5.9 weeks frequently undercounts multiple gestations. Initially undercounted multiple gestations and those correctly counted have similar pregnancy outcomes.     

Five-year follow-up after balloon pulmonary valvuloplasty

We hypothesized that gender and intrauterine growth retardation (IUGR) have greater effects than birth order on mortality and morbidity rates of very low birth weight (< 1501 gm) twins. Neonatal data were collected on 44 pairs of twins born alive between January 1984 and December 1987. Birth weight was 1018 +/- 289 gm and gestational age was 28.1 +/- 2.5 weeks. The male/female ratio was 46:42; 24 infants had IUGR, and 64 were appropriate in size for gestational age. Of the 88 infants, 61 (69%) survived. Birth order had no effect on outcome. Female twin pairs had a longer gestation than either male twin pairs or twins with discordant sex (29.2 +/- 2.5 weeks vs 27.4 +/- 2.0 weeks and 27 +/- 3 weeks, respectively; p < 0.002). They also had a lower mortality rate (14% vs 47% and 25%; p < 0.001) and a lower incidence of bronchopulmonary dysplasia (22% vs 57% and 50%; p < 0.02). Infants with IUGR had an increased mortality rate (50% vs 23%; p < 0.02) and an increased sepsis rate (61% vs 25%; p < 0.02) compared with infants with appropriate size for gestational age who were matched for gestational age. Multiple logistic regression analysis to assess the independent effects of gestational age, gender, and IUGR on mortality rate, bronchopulmonary dysplasia, and intraventricular hemorrhage revealed that gestational age was the most significant contributor to all three outcome variables; IUGR contributed to an increased mortality rate, and male gender contributed to the occurrence of bronchopulmonary dysplasia.     

First-trimester growth and the risk of low birth weight

BACKGROUND: Previous studies have demonstrated a correlation between first-trimester size and birth weight. It is not known, however, whether low birth weight is related to first-trimester growth. We sought to determine whether the risk of low birth weight and birth weight that was low for gestational age is related to the size of the embryo or the fetus in the first trimester. METHODS: From a data base of ultrasound records of more than 30,000 pregnancies, we identified women who had no important medical problems, a normal menstrual history, and a first-trimester ultrasound scan in which the crown-rump length of the embryo or fetus had been measured. We examined the relation between the outcome of 4229 pregnancies and the difference between the measured and the expected crown-rump length in the first trimester, expressed as equivalent days of growth. RESULTS: A first-trimester crown-rump length that was two to six days smaller than expected was associated with an increased risk (as compared with a normal or slightly larger than expected crown-rump length) of a birth weight below 2500 g (relative risk, 1.8; 95 percent confidence interval, 1.3 to 2.4), a birth weight below 2500 g at term (relative risk, 2.3; 95 percent confidence interval, 1.4 to 3.8), a birth weight below the fifth percentile for gestational age (relative risk, 3.0; 95 percent confidence interval, 2.0 to 4.4), and delivery between 24 and 32 weeks of gestation (relative risk, 2.1; 95 percent confidence interval, 1.1 to 4.0), but not with delivery between 33 and 36 weeks (relative risk, 1.0; 95 percent confidence interval, 0.7 to 1.5). CONCLUSIONS: Suboptimal first-trimester growth may be associated with low birth weight, low birth-weight percentile, and premature delivery.     

Effect of amniotic fluid volume on neonatal outcome in diamniotic twin pregnancies

PROBLEM: We assessed neonatal outcome of normal diamniotic twin pregnancies with known amniotic fluid (AF) volume. METHOD: The AF volume was empirically determined in 39 diamniotic twin gestations. The neonates were stratified by AF volume and evaluated for clinical outcome, gestational age, lecithin-sphingomyelin (L/S) ratio, and birth weight. RESULTS: Neonatal complications did not significantly differ among infants delivered from pregnancies with low (155 to 404 mL), moderate (405 to 807 mL), or high (808 to 5,430 mL) volumes of AF. Relatively constant volumes of AF were maintained throughout the 27 to 38 week range of gestational age, with no apparent correlation between AF volume and gestational age. Variations in the L/S ratio and newborn birth weights were also independent of AF volume. Gestational age was the only significant determinant of the frequency of neonatal complications. CONCLUSION: Amniotic fluid volume does not greatly affect neonatal outcome in normal diamniotic twin pregnancies.     

Physiologic differences between twin and single born beef calves in the first two days of life

Behavioral observations and hematological, serum biochemical and blood gas measurements were made on 8 naturally occurring twin calves during the first 48 hours of life. These values were compared to similar measurements collected from 30 single born calves, born under the same calving conditions. All calves survived to at least 3 weeks of age without physically detectable disease. Although the gestational age of the twins and singles were not different, the twins had a lower mean birth weight. Calving difficulty score, time interval to standing and time interval to nursing were not different between the 2 groups. Twin calves had significantly lower rectal temperatures, arterial oxygen tensions and blood glucose concentrations than the single calves through the first 12 hours of life. Hct, Hgb concentration, and RBC were lower in twin calves throughout the 48 hour period. The N:L ratio was lower in the twins at birth. Mean serum IgG1 concentrations were lower in twins only at 24 hours whereas IgM concentrations were lower at both 24 and 48 hours in twins. Serum chemistry value differences between twin and single calves were most numerous at 24 hours of age when serum proteins, urea nitrogen, total bilirubin, sodium, chloride, and total calcium concentrations were higher in the twins and serum phosphorus concentration was lower in the twins.     

Selective termination and elective reduction in twin pregnancies: 10 years experience at a single centre

Selective termination is employed in multifetal pregnancies, in the presence of an abnormal fetus, in order to improve the prognosis of the normal fetuses. The term elective reduction is used to describe reduction in twin pregnancies for maternal medical conditions, psychological, or socioeconomic reasons. The purpose of this study was to evaluate the factors that influence outcome in such pregnancies. Eighty-two twin pregnancies underwent selective termination (n = 59) or elective reduction (n = 23) over a 10-year period. Early procedures, performed < or = 14 weeks (n = 31), had a pregnancy loss of 9.7% and a mean procedure-to-loss interval of 4.1 +/- 2.8 weeks; mean birthweight was 3299 +/- 395 g in survivors, with a mean gestational age at delivery of 38.4 +/- 2.3 weeks. In comparison, procedures performed > 14 weeks (n = 51) had a pregnancy loss of 7.8%, with a procedure-to-loss interval of 1.2 +/- 0.6 weeks. Mean birthweight was 2577 +/- 999 g, with a mean gestational age at delivery of 35.7 +/- 5 weeks. In conclusion, outcomes were more favourable among patients who underwent a first trimester procedure. The slight increase in pregnancy loss may be attributed to a higher than expected rate of spontaneous abortions in the first trimester, as manifested by the higher procedure-to-loss interval after a first trimester procedure. These facts underscore the importance of early detection of fetal abnormalities in twin pregnancies by ultrasonography and chorionic villus sampling.     

Multifetal pregnancy reduction: evaluation of fetal growth in the remaining twins

OBJECTIVE: Our purpose was to study fetal growth after reduction of high-order multiple gestations to twins. STUDY DESIGN: Birth weight and gestational age data were collected for 236 triplet and greater multiple pregnancies reduced to twins (113 triplets, 89 quadruplets, and 34 quintuplets or above) and was compared with those of a control group of unreduced twins. RESULTS: Rates of intrauterine growth restriction per pregnancy were significantly different between the nonreduced and all categories of reduced multifetal pregnancies. The incidence of intrauterine growth restriction was 19.4% in the nonreduced twins, 36.3% in pregnancies reduced from triplets, 41.6% in pregnancies reduced from quadruplets, and 50% from higher-order multiple gestations. There was a statistically significant trend toward increasing frequency of intrauterine growth restriction with increasing starting fetal number (p = 0.04). The increase in intrauterine growth restriction was primarily accounted for by twin pairs with only one growth-restricted newborn. CONCLUSION: Multifetal pregnancy reduction does not reduce the incidence of intrauterine growth restriction in the remaining fetuses to that of nonreduced twins.     

Prevalence of cerebral palsy in twins, triplets and quadruplets

BACKGROUND: Twins and triplets are at higher risk of cerebral palsy than singletons. This study investigated the degree of risk for cerebral palsy in twins, triplets and quadruplets, and identified factors associated with the increased risk. METHODS: The subjects were recruited from the Kinki University Twin and Higher Order Multiple Births Registry. RESULTS: The subjects were 705 twins pairs (1410 twins), 96 sets of triplets (287 triplets excluding one infant death), and 7 sets of quadruplets (27 quadruplets excluding one infant death), who were born after 1977. The prevalence of cerebral palsy was 0.9% among 1410 twins, 3.1% among 287 triplets, and 11.1% among 27 quadruplets. Furthermore, the risks of producing at least one child with cerebral palsy were 1.5%, 8.0%, 42.9% in twin, triplet, quadruplet pregnancies, respectively. After adjusting for each associated factor using logistic regression, the risk of cerebral palsy was significantly associated with decrease in gestational age and asphyxia. The odds ratio indicated that infants whose gestational age was < 32 weeks were 20 times more likely to develop cerebral palsy than infants whose gestational age was > or = 36 weeks. CONCLUSIONS: The prevalence of cerebral palsy in triplets and quadruplets was higher than that in twins. Lower gestational age was associated with a greater risk of cerebral palsy.     

Zygosity and intrauterine growth of twins

Six hundred seventy-eight sonar measurements of the fetal biparietal diameter (BPD) were used to assess the intrauterine growth of 182 twins between 18 and 40 weeks' gestation. These values, as well as the weight and body length at birth, were related to the zygosity, which was determined by sex of the infants, histologic examination of placenta, or blood grouping. The mean BPD of twin 1 was larger than that of twin 2 in both monozygotic and dizygotic pairs throughout the study period (P less than .001). The size of BPD of the dizygotic infants exceeded that of the monozygotic among both twin 1 (P less than .001) and twin 2 (P less than .001). The absolute intrapair differences of birth length and weight were larger among dizygotic than among monozygotic twins. These findings suggest that in late pregnancy a substantial one-way intertwin transfusion among monochorial twins does not occur frequently enough to mask the inherent genetically determined similarity between the twins. The appearance already in the second trimester of the difference in the longitudinally monitored BPD between monozygotic and dizygotic twins suggests that the discrepancy is determined early in gestation.     

Perinatal outcome of pregnancies after assisted reproduction: a case-control study

PURPOSE: A matched case-control study of all pregnancies obtained after either IVF or ICSI was conducted to investigate the perinatal outcome. METHODS: Three hundred eleven singleton and 115 twin pregnancies obtained after assisted reproduction were studied. Controls were selected from a regional register and were matched for maternal age, parity, singleton or twin pregnancy, and date of delivery. RESULTS: No significant difference was observed for gestational age at delivery, birth weight, incidence of congenital anomalies, and incidence of perinatal mortality between ART (singleton and twin) pregnancies and spontaneous controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies (52 vs 42%; P < 0.05) and needed more neonatal intensive care (47 vs 26%; P < 0.05). CONCLUSIONS: From this case-control study it is concluded that the perinatal outcome of ART singleton pregnancies is not different from that in matched controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies and needed more neonatal intensive care.     

Risks of subsequent pregnancies on mother and newborn in female heart transplant recipients

BACKGROUND: Female heart transplant recipients are able to carry pregnancies successfully. This study evaluates the effect of subsequent pregnancies on newborn and maternal outcomes and graft survival. METHODS: Subjects were identified through a previously reported multicenter study, case reports from literature review, and recipients entered in the National Transplantation Pregnancy Registry. A retrospective analysis was completed of 35 heart transplant recipients with first pregnancies (FP) and 12 who had one or two additional pregnancies (P>1). Newborns were assessed for gestational age, neonatal birth weight, and complications. Maternal data included pregnancy outcome, peripartum complications, including infection and rejection, current graft function, and recipient survival. RESULTS: Forty-seven pregnancies (35 FP and 12 P>1) from 35 heart transplant recipients were studied. FP outcomes included 26 live births (one set of twins), four miscarriages, and six therapeutic abortions, whereas P>1 outcomes included 11 live births (one set of twins), and two miscarriages. There was no significant difference between mean birth weights (2353+/-986 gm vs 2588+/-521 g, P>1 vs FP; mean+/-SD; p=NS) or prematurity incidence (<37 weeks; 50% vs 40%; p=NS) for the live-born infants. Compared with the FP group, there was a trend toward increased neonatal complications in P>1 (40% vs 12%; p=NS). Complications were significantly more common in premature newborns compared with full-term newborns (33% vs 5%; p < 0.05). No structural malformations were identified in the live-born infants. Maternal complication rates were the same in both groups (40%). Of 28 recipients available for follow-up, the maternal survival rate was 75% for the FP group and 89% for the P> group. Mean rejection rate per year was slightly increased after pregnancy in the P>1 group. Surviving recipients had similar graft function by echocardiographic left ventricular ejection fraction. CONCLUSIONS: Post-heart transplantation pregnancies often have successful outcomes, but there is a high incidence of prematurity and low birth weight. Subsequent pregnancies do not seem to significantly increase the incidence of complications in either the newborn or mother or increase graft rejection or failure. Larger studies of posttransplantation pregnancies may provide more definitive information.