Unfortunately, preventing preterm labor with multiples is more challenging than with a singleton pregnancy because the interventions used with singleton pregnancies are not as effective with multiples. Scientific data show that bed rest does not prevent preterm delivery. In fact, bed rest can increase your risk of developing blood clots and have negative financial and social consequences.
During delivery is when things differ significantly. This is a safety precaution known as a double setup. Following the vaginal delivery of the first baby, there is a small risk of an emergency cesarean section for the second baby. There is also the possibility of the second twin being delivered breech, which is a safe form of vaginal delivery if the obstetrician is experienced in this type of delivery. Of women giving birth to twins over 32 weeks, only about 4 percent who try for a vaginal delivery will have a combined vaginal and cesarean section delivery.
Although being pregnant with twins can seem very different, your doctor will treat your pregnancy like any other unless a complication occurs. One of the best things you can do to protect and improve your health is to stay informed.
Do twins share a placenta and an amniotic sac? Here are three major possibilities that exist: Two placentas and two amniotic sacs. A twin pregnancy with two placentas and two amniotic sacs is the optimal twin pregnancy, as each baby has its own nutritional source and protective membrane. One placenta and two amniotic sacs. In pregnancies with one placenta and two amniotic sacs, you will definitely have identical twins.
We used a large population-based clinical data born in British Columbia BC and linked the fetal-maternal data to hand-searched pathology reports of twin placentas from twins born in BC Women hospital.
We analyzed the data using generalized estimating equations taking the cluster nature of twins into consideration. About Most twins were male Of the sex concordant twins, similar percentages were male-male Of the sex discordant twins, the male-female Twins of either sex from sex-discordant pairs were less likely to have placental anastomosis compared to the reference category. Peer Review reports. Adverse perinatal outcomes and fetal growth have been found to be associated with fetal sex [ 1 ].
None of the findings in the literature has led clinicians to pay attention to sex during perinatal screening, mostly because the mechanisms that confer these differences between the sexes are unknown.
It is also possible that the association between adverse perinatal outcomes and fetal sex is not that strong or that other factors, rather than fetal sex, such as chorionicity play a stronger role. A paucity of data exists in the literature regarding the relationship between sex and pathology of the placenta and cord.
Previous studies of pathology findings tend to focus on factors other than infant sex, such as birth weight discordance BWD [ 4 ]. A histological examination of placentas and umbilical cords of infants born at 23 to 32 weeks, cultured for aerobic and anaerobic bacteria, showed that male infants were significantly more likely to have placental membrane bacterial infection than female infants [ 6 ].
Figure 1 shows images of placenta histology and various complications. Literature has not much to offer about twin data. Our study aimed to investigate several pathological characteristics of the placenta associated with fetal sex. The pathology data were then linked to delivery outcome data such as gestational age and birth weight by Perinatal Services British Columbia PSBC [ 7 ].
The link was possible using the personal health number, maternal and baby identification number and date of birth. Infants from a female-female pairing were considered as the referent group. All placenta and cord pathology data were outcome variables. The pathology data of placenta were collected and labeled as A 1 cord clamp or B 2 cord clamps according to birth order. Placentas were placed in plastic bags after delivery and kept at 4 degrees centigrade until processed, usually within 24 h of delivery.
Pathologists who examined the placentas had access to the clinical information. The placentas were placed on a clean surface, adherent clots were removed, and the membranes and umbilical cords were excised before they were weighed. There was a systematic approach to attribute placental mass to each twin so that the total placental weight was recorded for each placenta.
In DC placentas with fused placentas, the proportion of placenta belonging to each twin was determined by measuring the length, width, and thickness in each of the two placental disks. Measurement of placental thickness was carried out in three areas of the placental disk, and the mean thickness was then recorded.
Cord length and its distances from the placenta margin, from the membrane and from the other cord were also measured. Umbilical cord insertions into the disc of the placenta and more than 1 cm away from the marginal border were defined as para central, cord insertions within 1 cm of the disc edge were defined as marginal and cord insertions directly into the membranes were defined as velamentous.
The number of vessels in the cord was recorded. A composite variable was created from cord properties inclusive of cord prolapse, number of cord vessels less than 3, and existence of cords knots or entanglements. The evaluation of placental chorionicity was performed by examination of the inter-twin membrane.
Separated twin placentas were examined in the same way as those of singletons. Fused placentas can be MC or DC. The dividing membrane was examined to identify chorionicity. The dividing membrane in a MC pregnancy is thin and translucent without any chorionic layer, while that of a DC placenta is thicker as it contains two chorionic layers between the amniotic sacs.
Identification of T form was considered confirmation of chorionicity. In histological examination of the placenta, vascular-thrombotic lesions infarction, chorangioma, subchorial fibrin deposition, and retro placental hematoma were recorded Image 1. Arteries were identified as vessels that are situated superficial in relation to the veins. A composite score was created for all of the pathological lesions for the purpose of analysis.
Anastomosis between fetal vessels was recorded. Anastomosis was identified by the presence of an impaired vessel from one twin feeding an area drained by the co-twin. Injection studies were performed in fresh specimen to identify unidirectional arteriovenous shunt s between donor and recipient.
Placentas were also assessed for maternal or fetal inflammatory response corresponding to chorionisits, chorioamnioitis, and chorionic villi inflammation. A composite variable was created using these items plus cases with inflammation or infection of the maternal or fetal side of the chorionic membrane.
Diagnosis of twin to twin transfusion syndrome TTTs was made by the referring obstetrician and was designated on the pathology requisition. Placenta abruptio and invasive of trophoblast such as placenta accreta was also recorded.
Completed pathology reports for twins were printed from online pdf records or from hard copies of pathology records stored in hospital charts. Data were then abstracted from these records into an Excel database.
We chose to exclude the latter category of vanishing twins from this analysis because of an association between sex discordance and vanishing twins [ 9 ]. Twins are of special interest because they provide naturally matched pairs where the confounding effects of many potentially causal factors such as maternal nutrition or gestation length may be removed by comparisons between twins who share them.
Bivariate analysis was used to determine significant variables that were to be included in the generalized estimating equation GEE regression analysis.
We used this method of analysis because we were mindful of the correlation between twins and the cluster nature of twins in to account. We used GEE analysis throughout the whole paper. However, we choose two approaches: 1. By comparing these two approaches, we can present a complete picture for the impact of sex on pathological findings. Therefore, we investigated the relationship between sex pairing and pathological findings.
Female-female group was considered the reference group for further analysis. The mode of delivery was more frequently cesarean section than vaginal delivery The sample was composed of males Two cases were identified with unknown sex and were excluded from the analysis.
Higher frequencies of chorionitis, anastomosis, unequal placenta sharing, inflammation and placenta lesions were found in males compared with female twins.
Cord length was about 1. These variables were then further analyzed by regression analysis Table 1. We were interested in estimating the total association of fetal sex pairing on pathology adverse outcomes. Of the eight categorical outcomes under study, unequally shared placenta and anastomosis and placental inflammation were the most common Table 3.
The frequency of seven variables anastomosis, unequal placenta sharing, composite of inflammation, placenta weight, length and width.
Cord length was also significantly different between sex pairs of different types among sex groups is significate different as the P value was found to be less than 0. Cord length was also significantly different between sex pairs of different types. However, except for anastomosis and unequal placenta sharing, the difference between categories was clinically small.
Thus, no further analysis was performed. Compared to females from the FF group the reference category , twins of either sex from mixed-sex pairs were less likely to have anastomosis. Males from MM pairs had a statistically significant increase in their odds of anastomosis compared with females from FF pairs 1. The odds of unequal placental sharing were highest in males from male-male pairs 1.
After adjustment for chorionicity, the odds remained statistically significantly high 1. Similarly, the adjusted for chorionicity and gestational age odds of composite inflammation were higher in males with male-male status compared to females of female-female pairs 1. Linear regression analyses were used to analyze the association between sex pairing and placenta weight, length, and width. From one level of sex pairing to the other, placenta weight decreases, on average, by about 10 g. Girl-boy twins occur when one X egg is fertilized with an X sperm, and a Y sperm fertilizes the other X egg.
Sometimes health care professionals identify same-sex twins as fraternal or identical based on ultrasound findings or by examining the membranes at the time of delivery. Occasionally a family is told that their twins are fraternal based on placenta findings, when they are in fact identical.
Other times, a family may see the minor differences in identical twins and declare the twins fraternal based on these differences in appearance. There are a few commercial laboratories that, for a fee, will send families DNA collection kits to determine if the twins are identical or fraternal.
Identical twins have the same DNA; however, they may not look exactly identical to one another because of environmental factors such as womb position and life experiences after being born. All twins, whether fraternal or identical, are truly 2 separate, unique individuals. You may be trying to access this site from a secured browser on the server.
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