Feasibility of a longitudinal study of women anticipating first pregnancy and assessed by multiple pelvic exams: recruitment and retention challenges.

OBJECTIVE: To better understand the relationship between childbirth and pelvic floor disorders the ideal study design would begin with data collection prior to but close in time to first pregnancy and follow participants through postpartum. We conducted a feasibility study to determine the following: a) whether women desiring to get pregnant would agree to pre-pregnancy data collection including a one-time urethral catheter measure and repeat pelvic exams to ascertain a baseline within 6 months of pregnancy; b) effectiveness of various recruitment and retention methods, c) number achieving pregnancy, and then d) number expressing willingness to continue follow-up through pregnancy and postpartum. METHODS: Advertising included newspaper ads, targeted emails and flyers. Post-enrollment, four data collection visits were scheduled and occurred every 6 months or until pregnant. If pregnancy occurred, women were asked to indicate their willingness to continue assessments. RESULTS: The most successful advertising strategy for both recruitment and retention was local newspaper ads. Ninety-four women inquired about the study, 30 enrolled. Post-baseline retention was 23 women at 6 months, 17 at 12 months, and 13 at 18 months. Nine of the 30 women achieved pregnancy; two remained eligible and willing to participate through pregnancy and postpartum. CONCLUSIONS: This study provides data on feasibility of recruiting women to establish near-pregnancy clinical baseline measures that include pelvic exams. Close to 30% reached pregnancy within 2 years of study start and within 6 months of most recent pelvic exam measure. Of those who became pregnant, 22% expressed willingness to continue follow-up into the childbearing year.

Perinatal and early childhood outcomes of twins versus triplets.

The purpose of this prospective cohort study of twins and triplets was to evaluate perinatal and early childhood outcomes through 18 months of age. The study population included 141 twin pregnancies (282 twin children) and 8 triplet pregnancies (24 triplet children) recruited between May, 1996 and June, 2001. Mothers of triplets versus twins were significantly more likely to have infertility treatments, to be overweight or obese before conception, to be admitted antenatally, and to deliver by cesarean section. Length of gestation for triplets was significantly shorter (-2.31 weeks, p < .0001), and more likely to be less than 35 weeks (Adjusted Odds Ratio [AOR] 9.38, 95% confidence interval [CI] 3.22-27.29). Average birthweight for triplets was significantly lighter (-495 grams, p < .0001), and more likely to be low birthweight (AOR 11.38, 95% CI 3.11-41.61). Triplets were also more likely to be admitted to neonatal intensive care (AOR 7.97, 95% CI 2.13-29.77), to require mechanical ventilation (AOR 5.67, 95% CI 2.05-15.65), to develop respiratory distress syndrome (AOR 12.50, 95% CI 3.89-40.20), or a major morbidity (retinopathy of prematurity, necrotizing enterocolitis, ventilator support, or grade III or IV intraventricular hemorrhage, AOR 5.67, 95% CI 2.05-15.65). Weight, length, and head circumference was significantly smaller at birth for triplets compared to twins, and these differences remained through 18 months of age, along with lower mental developmental scores at the oldest age. Compared to twins, triplets have greater neonatal morbidity, and through 18 months of age lower mental and motor scores, slower postnatal growth and more residual stunting, particularly of length and head circumference.

The Hispanic paradox in twin pregnancies.

The objective of this study was to compare length of gestation, fetal growth, and birthweight by race/ethnicity and pregravid weight groups in twin pregnancies. Three thousand and thirty-six twin pregnancies of 28 weeks or more gestation were divided by race/ethnicity (White, Black and Hispanic), and pregravid body mass index (BMI) groups (less than 25.0 vs. 25.0 or more). Outcomes were modeled using multiple regression, controlling for confounders, with White non-Hispanic women as the reference group. Hispanic women had the highest average birthweight and the longest gestation, as well as the lowest proportions of low birthweight, very low birthweight, preterm and early preterm births of the 3 race/ethnicity groups. In the multivariate analyses, Hispanic women had significantly longer gestations (by 7.8 days) and faster rates of fetal growth midgestation (20 to 28 weeks, by 17.4 g/week) and late gestation (after 28 weeks, by 5.3 g/week), whereas Black women had significantly slower rates of fetal growth (by 5.7 g/week and by 4.5 g/week, respectively). These findings in twins reflect the racial and ethnic disparities previously shown in singletons, including the Hispanic paradox of longer gestations and higher rates of fetal growth.

Elevated maternal glucose concentrations and placental infection in twin pregnancies.

OBJECTIVE: To evaluate the association between maternal screening glucose concentration and placental infection in nondiabetic twin pregnancies. STUDY DESIGN: One thousand sixty-one nondiabetic twin pregnancies at > or =28 weeks' gestation were divided into 3 groups based on the screening 50-g fasting glucose concentration at 24-28 weeks: lowest quartile (< 96 mg/dL), middle 2 quartiles (96-128 mg/dL) and upper quartile (> 128 mg/dL). Outcomes were modeled using general linear and multinomial logistic regression, controlling for confounding factors. RESULTS: The middle and highest glucose groups were associated with increased risks for clinical chorioamnionitis (adjusted OR [AOR] 3.18, 95% CI 1.34, 7.54; AOR 6.80, CI 1.89, 24.53, respectively). Birth at <32 weeks and histologic diagnosis of placental infection (chorioamnionitis, funisitis, necrosis, vasculitis or villitis) were significantly associated only with the highest glucose group (AOR 1.79, CI 1.02, 3.13; AOR 6.95, CI 1.10, 8.68, respectively). CONCLUSION: Elevated screening glucose in nondiabetic twin pregnancies may be a marker of placental inflammation and infection.

The cost of twin pregnancy: maternal and neonatal factors.

OBJECTIVE: The purpose of this study was to evaluate factors affecting birth charges in twin pregnancies. STUDY DESIGN: Clinical and financial data were obtained on 1486 twin pregnancies delivered between 1995 to 2002 at medical centers in Maryland, Florida, Michigan, and South Carolina. Maternal and neonatal length of stay (LOS) and charges were modeled by gestational age and other risk factors using a general linear model. RESULTS: Maternal and infant birth admission LOS and charges increased significantly with a decline in gestational age. Maternal LOS and charges were also significantly increased by cesarean delivery and preeclampsia. Newborn LOS and charges increased significantly by monochorionicity and slowed growth between 20 to 28 weeks. For mother and infants, the shortest LOS and lowest birth charges were at 37 to 38 weeks. CONCLUSION: These findings reflect the substantial maternal and neonatal morbidity associated with twin pregnancies, and demonstrate that 37 to 38 weeks is their optimal gestation.

Gender mix in twins and fetal growth, length of gestation and adult cancer risk.

This study evaluated the effect of gender mix (the gender combinations of twin pairs) on fetal growth and length of gestation, and reviewed the literature on the long-term effects of this altered fetal milieu on cancer risk. In singletons, it is well established that females weigh less than males at all gestations, averaging 125-135 g less at full term. This gender difference is generally believed to be the result of the effect of androgens on fetal growth. The gender difference in fetal growth is greater before the third trimester and less towards term, with males growing not only more, but also earlier than females. Plurality is a known risk factor for reduced fetal growth and birthweight. Compared with singletons, the mean birthweight percentiles of twins fall substantially (by 10% or more) below the singleton 10th percentile by 28 weeks, below the singleton 50th percentile by 30 weeks, and below the singleton 90th percentile by 34 weeks. In unlike-gender twin pairs, it has been reported that the female prolongs gestation for her brother, resulting in a higher birthweight for the male twin than that of like-gender male twins. Other researchers have demonstrated that females in unlike-gender pairs had higher birthweights than females in like-gender pairs. Analyses from our consortium on 2491 twin pregnancies with known chorionicity showed longer gestations and faster rates of fetal growth in both males and females in unlike-gender pairs compared with like-gender male or female pairs, although these differences were not statistically significant. The post-natal effects for females growing in an androgenic-anabolic environment include increased sensation-seeking behaviour and aggression, lowered visual acuity, more masculine attitudes and masculinising effects of the auditory system and craniofacial growth. In contrast, there is no evidence to suggest that there might be a similar feminising effect on males from unlike-gender pairs. This hormonal exposure in utero may influence adult body size and susceptability to breast cancer.

Fetal phenotypes and neonatal and early childhood outcomes in twins.

OBJECTIVES: The purpose of this study was to evaluate factors associated with, and postnatal consequences of, altered patterns of fetal growth in twins. STUDY DESIGN: Fetal growth was measured at 28 weeks' gestation on 218 twins, including head circumference, abdominal circumference, and femur length, and characterized as > or < or =10th %ile; children were followed up until the age of three years. Logistic regression was used to generate odds ratios of perinatal factors associated with reduced fetal growth. RESULTS: Maternal height <62 inches was associated with reductions in femur length (adjusted odds ratio [AOR] 3.88, 95% CI 1.42-10.57) and abdominal circumference (AOR 8.63, 95% CI 2.41-30.94), while primiparity had a protective effect on both of these fetal measurements (AOR 0.28, 95% CI 0.13-0.64, and AOR 0.18, 95% CI 0.06-0.60, respectively), as well as head circumference (AOR 0.32, 95% CI 0.15-0.69). Smoking adversely affected femur and head growth (AOR 24.10, 95% CI 3.69-157.57, and AOR 10.82, 95% CI 1.73-67.79, respectively). Fetal reduction adversely affected femur and abdomen growth (AOR 5.85, 95% CI 1.52-22.51 and AOR 4.90, 95% CI 1.01-23.86, respectively), and monochorionicity and maternal weight gain <0.65 lb/wk before 20 weeks adversely affected femur growth (AOR 5.47, 95% CI 1.65-18.10, and AOR 3.39, 95% CI 1.34-8.59, respectively). At age 3 years, all categories of twins with reduced growth by 28 weeks' gestation were significantly shorter in height, and those with reduced abdominal circumference or head circumference at 28 weeks were also significantly lighter in weight compared with twins with adequate fetal growth by 28 weeks' gestation. CONCLUSION: These data identify short maternal height, smoking, monochorionicity, fetal reduction, and inadequate weight gain before 20 weeks as risk factors associated with reduced twin fetal growth by 28 weeks' gestation and significant residual reductions in height and weight through 3 years of age.