Sex ratio in triplets.

Since the introduction of different ovulation induction regimens the incidence of triplet pregnancies increased from a spontaneous rate of about 1:10,000 to the frequency of nearly 1:1000. Sex ratio of trigemini and male/female proportion of the three newborns within the same triplet set is the amazing issue that we attempted to elucidate in the present study. Data on 36 women with triplet pregnancies delivered in our hospital and information regarding 2717 triplet pregnancies reported by 16 relevant papers were included in this study. 36 women delivered 63 (58%) male and 45 (42%) female babies. Triplet sets of same gender comprised 33% of all trigemini. Sex ratios (male/female) for the spontaneous, menotropin and clomiphene group were 2.00, 1.57 and 0.94 respectively. Homogenous male/female set ratio was 5.0, 2.0 and 0.5 in menotropin, spontaneous and clomiphene groups respectively. As the percentage of ovulation induction triplet pregnancies increased constantly from 0% to 100%, a decline in the fraction of homogenous gender triplet sets was observed--from 73% to 23%. It may be concluded that sex ratio in triplet newborns is divergent according to different publications with most of the authors reporting a male/female ratio of less than 1.00. Ovulation induction results in a lower proportion of homogenous sex triplets sets. Superovulation by menotropins cause a higher percentage of male triplet newborns when compared to ovulation induction by clomiphene.

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.

Transverse versus longitudinal uterine incision in cesarean delivery of triplets.

It is commonly accepted that cesarean section is the preferred mode of delivery of triplets. The present study was performed to evaluate maternal complications and neonatal outcome in 21 women operated on by a transverse lower segment incision as compared to 8 parturients who underwent surgery by a longitudinal uterine incision. There was no significant difference in mean gestational age at delivery, mean weight of the newborns, Apgar scores, perinatal mortality rates, or intraoperative or postpartum hemorrhage incidence between the two groups. Thus, a transverse lower segment uterine incision should be used in triplet deliveries to increase the chances of a normal vaginal delivery in the future.

Discordancy in triplets.

Discordancy in twins is generally described as a weight difference between the fetuses of 15 to 25% and its prevalence in normal twin gestations is estimated at 15 to 29%. The present study was performed in order to determine the frequency of discordant newborns in uncomplicated triplet gestations. One hundred and fourteen normal triplet newborns were delivered during a period of 11 years. Their birthweight ranged from 493 to 2533 gm, with a mean of 1894.2 +/- 468.5 gm (+/- sd). In 58% of these 38 sets of triplets the difference in weight between the largest and smallest newborn was more than 15%. About a quarter of the newborns had a greater than 25% dissimilarity in their birthweights. There was no substantial fetal-fetal transfusion or difference in the Apgar scores between the discordant fetuses. It may be concluded that triplet newborns have a rate of discordancy double that of twins. Discordance per se does not necessarily mark an underlying complication of pregnancy or a bad perinatal outcome.

Sonographic growth curves of triplet conceptions.

The diagnosis of inappropriate intrauterine fetal growth in triplet pregnancies requires normal standard sonographically determined growth curves. The aim of the present study was to establish such nomograms. The biparietal diameter (BPD), femur length, head and abdominal circumferences (HC, AC) were once in 3 weeks sonographically evaluated in 108 normal triplet fetuses. The resulting growth curves were compared with those of normal singleton fetuses. The data showed that, compared with singletons, the mean triplet fetal BPD progressively lags to a maximum of 2 1/2 weeks as pregnancy continuous from the 25th to the 36th gestational week. Similarly, mean femur length of triplet fetuses gradually shortfalls to the greatest of 2 weeks as gestation advances from the 25th to the 36th week. HC to AC ratio of the triplet fetuses does not differ from the singletons curve. It may be concluded that a normal fetal growth curve in triplet pregnancies demonstrates a 1- to 3-week delay compared with singleton gestations.

Probability model for molecular recognition in biological receptor repertoires: significance to the olfactory system.

A generalized phenomenological model is presented for stereospecific recognition between biological receptors and their ligands. We ask what is the distribution of binding constants psi(K) between an arbitrary ligand and members of a large receptor repertoire, such as immunoglobulins or olfactory receptors. For binding surfaces with B potential subsite and S different types of subsite configurations, the number of successful elementary interactions obeys a binomial distribution. The discrete probability function psi(K) is then derived with assumptions on alpha, the free energy contribution per elementary interaction. The functional form of psi(K) may be universal, although the parameter values could vary for different ligand types. An estimate of the parameter values of psi(K) for iodovanillin, an analog of odorants and immunological haptens, is obtained by equilibrium dialysis experiments with nonimmune antibodies. Based on a simple relationship, predicted by the model, between the size of a receptor repertoire and its average maximal affinity toward an arbitrary ligand, the size of the olfactory receptor repertoire (Nolf) is calculated as 300-1000, in very good agreement with recent molecular biological studies. A very similar estimate, Nolf = 500, is independently derived by relating a theoretical distribution of maxima for psi(K) with published human olfactory threshold variations. The present model also has implications to the question of olfactory coding and to the analysis of specific anosmias, genetic deficits in perceiving particular odorants. More generally, the proposed model provides a better understanding of ligand specificity in biological receptors and could help in understanding their evolution.

Successful full-term pregnancy in familial Mediterranean fever complicated with amyloidosis: case report and review of the literature.

Pregnancy during familial Mediterranean fever complicated with amyloidosis and severe nephrotic syndrome is rare and may cause several maternal and fetal complications. Asymmetrical intrauterine growth retardation, superimposed preeclampsia, thromboembolic phenomena, resistant anemia and renal failure only partially represent the possible complications. A successful outcome of a full-term pregnancy is presented and the efficiency of colchicine, a high protein diet, acetylsalicylic acid and dipyridamole is discussed.

Elective suture of uterine cervix in triplets.

The incidence of triplet pregnancies has increased several times due to the widespread use of ovulation induction agents. Premature delivery is the main complication of triplet gestations. In twin conceptions it was shown definitely that elective cervical suture does not prolong these pregnancies. However, in higher order multifetal gestations the uterus is extremely overdistended and the application of cerclage is equivocal. This work intended to assess the value of elective cervical sutures in prolonging triplet pregnancies. Twelve of 35 women with triplet conceptions hospitalized at our high-risk pregnancy unit underwent an elective cerclage at 12 to 14 weeks and 23 women served as control subjects. None of them had any history or physical findings of cervical incompetence prior to the procedure. The gestational age (weeks) at delivery was 33.0 +/- 5.1 and 34.7 +/- 2.8 (mean +/- SD) for the sutured and noncerclage groups, respectively. The birthweight (grams) of the neonates was 1833.0 +/- 524.5 and 1884 +/- 455.5 (mean +/- SD) for the cerclage and nonsutured women, respectively. It seems that triplet gestations as such do not benefit from an elective cervical suture.

Triplets are not so rare any more.

Triplet gestations present a considerable management challenge due to a high rate of antenatal, intrapartum and neonatal complications. The introduction of ovulation inducing agents resulted in a marked increase of these pregnancies. Consequently, triplet conceptions are not considered a rare phenomenon and have become almost routine high risk pregnancies. In our department the triplet gestation frequency increased 2-4 times in a 10 year period from a rate of 0.07-0.14% during 1978-84 to 0.28% of all deliveries in 1987. This high incidence of triplet deliveries results in a threefold increase in the frequency of triplet neonates and their associated complications. It is reasonable to assume that the wide application of various assisted reproductive techniques will result in continuous increase in the incidence of triplets which will in turn require coordinated management of a high risk pregnancy unit, delivery room and neonatal intensive care unit.

Delay in the diagnosis of rupture of the uterus due to epidural anesthesia in labor.

A case report of uterine rupture in labor with epidural anesthesia is presented. The woman had good analgesia on the left side, but complained of severe labor pais on her right side. Uterine rupture occurred which was manifested by sudden vaginal bleeding, fainting, low blood pressure and fetal distress. She did not feel any pains typical of uterine rupture. Rupture of the left uterine wall, with a large hematoma in the left parametrium was seen at surgery. It seems the unilateral anesthesia of the left side concealed the early signs of rupture.

Maternal hemorrhagic complications following prophylactic low-dose aspirin and dipyridamole therapy.

A case is reported of a severe postpartum maternal hemorrhagic complication, which was related to prophylactic antithrombotic therapy with daily low-dose aspirin (75 mg) combined with dipyridamole (225 mg) for the prevention of preeclampsia. The postpartum course was complicated by recurrent episiotomy site hematomas of nonclotted blood and prolonged bleeding time. Transfusion of platelet concentrates was necessary to control the bleeding. This case report draws attention to maternal hemorrhagic complications which may be associated with prophylactic low-dose aspirin and dipyridamole in pregnancy.

Menotropins as a possible risk factor for premature deliveries in triplet pregnancies.

This study was undertaken in order to evaluate pregnancy outcome in three groups of triplet conceptions. Of 36 delivered triplet gestations, seven were spontaneous, 12 achieved using clomiphene citrate and 17 induced by menotropins. The mean gestational age (weeks) at delivery was 36.5 +/- 1.0 SD, for spontaneous and clomiphene citrate pregnancies it was 35.9 +/- 1.9 SD which differed significantly from that in pregnancies induced by menotropins which was 32.9 +/- 3.7 SD. Similarly, triplets born following menotropin treatment had a significantly lower gestational weight (g) of 1656 +/- 516 SD vs. 2015 +/- 198 SD and 2176 +/- 315 SD for spontaneous and clomiphene citrate gestations, respectively. It is concluded that triplets following menotropins are at an increased risk for premature delivery and low birth weight.

Incidence of spontaneous and evoked fetal movements in the first half of twin pregnancy.

Fetal movements (FM) may be spontaneous, originating in the fetus itself, or evoked, caused by external stimuli. The FM in 21 normal twin pregnancies at 10 and 21 weeks of gestation were studied. The percentage rate of evoked FM which occur simultaneously in both twins was 4.96% of all observed FM. The rate of the spontaneous FM which occur independently in each fetus was 95.04% of all FM. The low incidence of evoked FM, at an early gestational age (10-21 weeks) emphasizes the ability of these young fetuses to perceive external stimuli and to react to them by FM.

[The high risk pregnancy unit].

During the past 30 years there has been great progress in perinatology. However, perinatal mortality has remained relatively high. To reduce perinatal mortality and morbidity, high risk pregnancy units have been established throughout the world. Our unit was established in 1976 for women with diseases complicating pregnancy, and in whom evaluation of fetal respiratory and metabolic function is indicated. The cesarean section rate during these 12 years was 33%. There was no maternal mortality. The intrauterine fetal death rate was 10.3 per 1,000 (very low for this unique population) and the corrected perinatal mortality was 3.4 per 1,000. The monitoring and treatment protocols, developed and applied in this unit, resulted in a significant decrease in fetal morbidity and mortality. These dramatically improved results demonstrate and justify the need for high risk pregnancy units.

Twin gestations and prophylactic hospitalization.

The study evaluates the benefit of elective hospitalization in preventing premature deliveries of twin gestations. Three groups of women with twin gestations, having no other complications of pregnancy which could cause premature delivery, were evaluated. The study group was comprised of 43 women who were electively hospitalized between 30-32 and 36 weeks of gestation. Control group 1 was comprised of 55 women who were not hospitalized but were instructed to rest at home. Control group 2 was comprised of 53 women who were not hospitalized and were not instructed to rest at home. Our results showed that elective hospitalization did not significantly affect the gestational duration or the prematurity rate. However the mean birthweight difference between the study group and the two control groups were 143 +/- 83 g and 205 +/- 84 g, respectively. This result was more significant in multiparous women. The slight increase in birthweight of the hospitalized women compared to the controls, does not seem to justify the cost of hospitalization.

Sinusoidal fetal heart rate pattern associated with the twin to twin transfusion syndrome.

Sinusoidal fetal heart rate pattern (FHR) is regarded by most authors as signifying a compromised fetus. In most cases, this is secondary to fetal anemia of different causes, usually Rh isoimmunization, more rarely to fetomaternal transfusion, bleeding vasa previa, placental chorioangioma, or traumatic amniocentesis. A case is described which to our knowledge is the first reported of a sinusoidal FHR pattern occurring in the relatively anemic donor twin in a case of the twin to twin transfusion syndrome. The importance of separate antepartum biophysical evaluation of each member of a twin pregnancy is emphasized.

Successful pregnancies of two patients with relapsing thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura is a severe multisystemic disorder of unknown origin. The association of relapsing TTP with pregnancy is rare but well documented and high mortality rates of mothers and fetuses have been reported so far. Since the introduction of plasma therapy for treating the acute exacerbations of the disease, overall mortality rates have decreased significantly. It is now evident that the manifestations of the disease may reappear even after long disease-free intervals and as many as a third of the recovering patients may develop a relapse. Presented are two TTP patients with relapsing TTP complicating their pregnancies. Prophylactic treatment with aspirin and dipyridamole during their last three successful pregnancies prevented or minimized the severity of TTP relapses. The course of these pregnancies and the management of such patients is discussed.

Severe fetal bradycardia caused by external vibratory acoustic stimulation.

A case is presented in which external vibratory acoustic stimulation performed on a term fetus produced severe prolonged bradycardia, necessitating emergency cesarean section delivery. The possible pathogenesis is discussed.