James Dornan

Definition of intertwin birth weight discordance.

OBJECTIVE: To establish the level of birth weight discordance at which perinatal morbidity increases in monochorionic and dichorionic twin pregnancy. METHODS: This prospective multicenter cohort study included 1,028 unselected twin pairs recruited over a 2-year period. Participants underwent two weekly ultrasonographic surveillance from 24 weeks of gestation with surveillance of monochorionic twins two-weekly from 16 weeks. Analysis using Cox proportional hazards compared a composite measure of perinatal morbidity (including any of the following: mortality, respiratory distress syndrome, hypoxic–ischemic encephalopathy, periventricular leukomalacia, necrotizing enterocolitis, or sepsis) at different degrees of birth weight discordance with adjustment for chorionicity, gestational age, twin–twin transfusion syndrome, birth order, gender, and growth restriction. RESULTS: Perinatal outcome data were recorded for 977 patients (100%) who continued the study with both fetuses alive beyond 24 weeks, including 14 cases of twin–twin transfusion syndrome. Adjusting for gestation at delivery, twin order, gender, and growth restriction, perinatal mortality, individual morbidity, and composite perinatal morbidity were all seen to increase with birth weight discordance exceeding 18% for dichorionic pairs (hazard ratio 2.2, 95% confidence interval [CI] 1.6–2.9, P<.001) and 18% for monochorionic twins without twin–twin transfusion syndrome (hazard ratio 2.6, 95% CI 1.6–4.3, P<.001). A minimum twofold increase in risk of perinatal morbidity persisted even when both twin birth weights were appropriate for gestational age. CONCLUSION: The threshold for birth weight discordance established by this prospective study is 18% both for dichorionic twin pairs and for monochorionic twins without twin–twin transfusion syndrome. This threshold is considerably lower than that defined by many retrospective series as pathologic. We suggest that an anticipated difference of 18% in birth weight should prompt more intensive fetal monitoring. LEVEL OF EVIDENCE: II

Sex differences in fetal mouth movements

Sex differences in behaviour have been widely studied after birth, whereas behavioural studies of the fetus have largely overlooked sex differences, although it has been reported that female fetuses habituate earlier than males. However, given the presence of sex differences in the newborn infant, the current view of continuity of development would suggest that sex differences do not appear at birth but have their developmental origins in the prenatal period. We have observed one sex difference present before birth. Fetuses of 39 pregnant women were examined. All were singleton pregnancies with no obstetric problems and all resulted in normal healthy babies at term. 20 women gave birth to female offspring, 19 to male. Ethical approval for the study was given by the Research Ethics Committee, Faculty of Medicine, Queen’s University of Belfast. All women gave written informed consent to take part in the study. Women were scanned at 16, 18, and 20 weeks of gestation as part of a study examining the behaviour of the fetus at the same age as its routine ultrasound scan to check for structural anomalies (16–20 weeks). These observations were done separately from their anomaly scan. Fetuses were observed for 60 min with an Ultramark 4 plus or Dornier AI3200 ultrasound scanner. A longitudinal view of the fetus’s body and head was obtained and this was recorded on videotape for later analysis. The videotapes were replayed and the number of mouth movements exhibited by each fetus at each gestational age counted. Mouth movements were defined as movements of the jaw which may or may not include tongue movements. A mixed design analysis of variance was done for the betweensubject factor of sex (male or female) and within-subject factor of gestational age (16, 18, 20 weeks of gestation). Mouth movements increased with advancing gestational age (p<0·001, see figure). Females were found to move their mouths more than males (p=0·021, figure). Mouth movements per se may have little function for the fetus but are essential for the newborn infant to enable it to suck, gain nourishment, and hence survive. It is therefore not surprising that such movements appear early in gestation and occur frequently thus ensuring their adequate development by the time of birth. Our results indicate a sex difference in behaviour of the human fetus from early in gestation. Females are developmentally more advanced than males, both preterm and at term, and the difference observed here may reflect a more general ontogenetic pattern of advanced female development compared with males, perhaps beginning at conception. The observation of a sex difference in behaviour at such an early age favours a biological explanation of its cause although the proximate mechanism remain(s) to be determined. The presence of sex differences in the behavioural development of the fetus may reflect a more fundamental difference in the developmental pattern of males and females. Futher investigations are underway to explore possible differences. However, researchers should be aware of the potential for differences in behaviour according to fetal sex.

Placental cord insertion and birthweight discordance in twin pregnancies: results of the national prospective ESPRiT Study

OBJECTIVE The purpose of this study was to evaluate the impact of noncentral placental cord insertion on birthweight discordance in twins. STUDY DESIGN We performed a multicenter, prospective trial of twin pregnancies. Placental cord insertion was documented as central, marginal, or velamentous according to a defined protocol. Association of the placental cord insertion site with chorionicity, birthweight discordance, and growth restriction were assessed. RESULTS Eight hundred sixteen twin pairs were evaluated; 165 pairs were monochorionic, and 651 pairs were dichorionic. Monochorionic twins had higher rates of marginal (P = .0068) and velamentous (P < .0001) placental cord insertion. Noncentral placental cord insertion was more frequent in smaller twins of discordant pairs than control pairs (29.8% vs 19.1%; P = .004). Velamentous placental cord insertion in monochorionic twins was associated significantly with birthweight discordance (odds ratio, 3.5; 95% confidence interval, 1.3-9.4) and growth restriction (odds ratio, 4; 95% confidence interval, 1.1-14.3). CONCLUSION Noncentral placental cord insertion contributes to birthweight discordance in monochorionic twin pregnancies. Sonographic delineation of placental cord insertion may be of value in antenatal assessment of twin pregnancies.

Prediction of safe and successful vaginal twin birth

OBJECTIVE The objective of the study was to establish predictors of vaginal twin birth and evaluate perinatal morbidity according to mode of delivery. STUDY DESIGN One thousand twenty-eight twin pregnancies were prospectively recruited. For this prespecified secondary analysis, obstetric characteristics and a composite of adverse perinatal outcome were compared according to the success or failure of a trial of labor and further compared with those undergoing elective cesarean delivery. Perinatal outcomes were adjusted for chorionicity and gestational age using a linear model for continuous data and logistic regression for binary data. RESULTS Nine hundred seventy-one twin pregnancies met the criteria for inclusion. A trial of labor was considered for 441 (45%) and was successful in 338 of 441 (77%). The cesarean delivery rate for the second twin was 4% (14 of 351). Multiparity and spontaneous conception predicted vaginal birth. No statistically significant differences in perinatal morbidity were observed. CONCLUSION A high prospect of successful and safe vaginal delivery can be achieved with trial of twin labor.

Long-term flavor recognition in humans with prenatal garlic experience

The human fetus learns about its chemosensory environment and this influences its behavior at birth and during the nursing period. This study examined whether prenatal experience could influence behavior much later in life. The dietary preference of two groups of children (8- to 9-years old) was examined. Mothers of one group had consumed garlic during pregnancy, mothers of the control group had not. Children received two tests, 1 month apart, of a meal containing two portions of potato gratin, one flavored with garlic. The total amount of potato, and the percentage of garlic flavored potato, eaten was calculated and examined separately by ANOVA for factors of prenatal exposure, the childs sex, and trial. Children prenatally exposed to garlic ate significantly more garlic flavored potato and a significantly greater overall amount of potato on trial 2, compared to controls. The results demonstrate prenatal experience may affect behavior well into childhood.

Maternal alcohol consumption during pregnancy and fetal startle behaviour

The startle behaviour of the fetus (both spontaneous and elicited) was examined in fetuses of mothers who drank alcohol and mothers who did not. Fetuses exposed to alcohol showed a higher frequency of spontaneous startles and were less likely to exhibit a normal startle in response to a vibroacoustic stimulus. These differences illustrate a teratogenic effect of alcohol on CNS functioning in utero, possibly associated with brainstem damage.

Detection of foetal growth restriction using third trimester ultrasound

Foetal growth restriction is an important contributor to perinatal mortality, being responsible for up to 50% of stillbirths. Optimal prevention and accurate detection enabling timely intervention remain elusive, particularly in presumed low-risk pregnancy. Third trimester ultrasound seems a logical solution, but systematic review of evidence from randomised trials has shown that third trimester ultrasound does not have a significant impact on perinatal mortality but may increase interventions such as caesarean delivery. However, the evidence is difficult to interpret in the context of current obstetric practice as the evolution of ultrasound technology and rapid assimilation of newer techniques has resulted in questionable validity of the findings. If third trimester ultrasound were introduced routinely, there is a need to decide the optimal timing and number of examinations and what ultrasound parameters should be used to identify the foetus at risk.

Prediction of outcome in twin pregnancy with first and early second trimester ultrasound

Abstract Objective: To establish if first or second trimester biometry is a useful adjunct in the prediction of adverse perinatal outcome in twin pregnancy. Methods: A consecutive cohort of 1028 twin pregnancies was enrolled for the Evaluation of Sonographic Predictors of Restricted growth in Twins (ESPRiT) study, a prospective study conducted at eight academic centers. Outcome data was recorded for 1001 twin pairs that completed the study. Ultrasound biometry was available for 960 pregnancies. Biometric data obtained between 11 and 22 weeks were evaluated as predictors of a composite of adverse perinatal outcome (mortality, hypoxic ischemic encephalopathy, periventricular leukomalacia, necrotizing enterocolitis, respiratory distress, or sepsis), preterm delivery (PTD) and birthweight discordance greater than 18% (18% BW). Outcomes were adjusted for chorionicity and gestational age using Cox Proportional Hazards regression. Results: Differences in crown-rump length (CRL) were not predictive of adverse perinatal outcome. Between 14 and 22 weeks, a difference in abdominal circumference (AC) of more than 10% was the most useful predictor of adverse outcome, PTD and 18% or more BW discordance in all twins. Overall the strongest correlation was observed for intertwin differences in biometry between 18 and 22 weeks. Conclusion: Biometry in the early second trimester can successfully identify twin pregnancies at increased risk. Intertwin AC difference of greater than 10% between 14 and 22 weeks gestation was the best individual predictor of perinatal risk in all twins. Sonographic biometry in the early second trimester should therefore be utilized to establish perinatal risk, thus allowing prenatal care to be improved.

What is to blame for postnatal pelvic floor dysfunction in primiparous women—Pre-pregnancy or intrapartum risk factors?

BACKGROUND The aetiology of pelvic floor dysfunction (PFD) is still poorly understood. However childbearing is recognized as a major risk factor. OBJECTIVES To elucidate the natural history of PFD by investigating the impact of the mode of delivery on postnatal pelvic floor dysfunction in primiparas, when PFD existing before the first pregnancy is taken into consideration. STUDY DESIGN 4P-study (Prevalence and Predictors of Pelvic floor dysfunction in Primips) is a prospective cohort study, nested within the Screening for Pregnancy Endpoints (SCOPE) study set in a tertiary referral teaching hospital with 9000 deliveries annually. Established and proposed risk factors for urinary, fecal, prolapse and sexual dysfunction and the severity of symptoms for each of these outcomes were assessed using the Australian Pelvic Floor Questionnaire in 1482 nulliparous women, who each completed the questionnaire in early pregnancy. Of these, 1060 (72%) repeated the questionnaire 12 months postpartum.Outcomes were analyzed using multivariate ordinal logistic regression. RESULTS Significant (p<0.05) risk factors for postpartum PFD were pre-pregnancy presence of similar symptoms Odds Ratio (OR) (5.0-30.0), smoking (OR 2.2-4.6), recurrent UTI (OR 2.2-17.3), high hip circumference (OR1.4-1.6), vigorous exercising (OR 3.1-17.9), induction of labor (OR 1.5-2.3), forceps delivery (OR 1.8-8.8), and 3rd degree perineal tear (OR 2.4-2.7). Cesarean section was associated with a lower risk of stress urinary incontinence (OR 0.3-0.5). Other common pre-pregnancy significant (p<0.05) risk factors for various PFD types prior to the first pregnancy were: diagnosed depression - (OR 1.6-2.1), high BMI (OR 3.1), strenuous exercising (OR 1.3-2.2), recurrent UTI (OR 1.5-2.5) and lower educational achievement (OR 1.5-1.6). CONCLUSIONS Pre-pregnancy PFD was mainly associated with modifiable risk factors such as smoking and exercising. The main risk factor for postpartum PFD was the presence of similar symptoms prior to pregnancy, followed by anthropometric and intrapartum factors. Hip circumference seems to be a better predictor of PFD compared to BMI. When pre-pregnancy PFD was included in the analysis, Cesarean section was protective only for stress urinary incontinence, while delivery by forceps increased the risk of prolapse.

Which twin is which

When the time came for her to give birth, there were twin boys in her womb. As she was giving birth one of them put out his hand: so the midwife took a scarlet thread and tied it on his wrist and said, ‘‘This one came out first’’. But when he drew back his hand, his brother came out and she said, ‘‘So this is how you have broken out!’’ and he was named Perez. Then his brother, that had the scarlet thread on his wrist, came out. And he was named Zera. Genesis 38 : 27–301