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Louis G Keith

Publications and source records attributed to Louis G Keith.

At least 37 records · Page 2Linked to original sources
PubMed2004

The ponderal index in triplets: II. Gestational age-related patterns of neonatal weights and lengths.

In order to evaluate the determinants of high and low ponderal indices in triplets, we analyzed prospectively collected data from a cohort of 2181 triplet births. Low and high neonatal ponderal indices (birth weight/[length]3) were defined as below or above 1 SD from the mean. The mean ponderal index was of 2.4 +/- 0.4. At 30-31 weeks, there were significantly more infants with a low ponderal index; after 33 weeks, more infants were born with a high index. Birth weights of infants with a high index were significantly higher throughout the entire range of gestational ages, whereas their lengths were significantly smaller. Both birth weights and infant length had significant correlations with gestational ages for infants with a low (R2=0.97 and R2=0.94, respectively) as well as with high ponderal indices (R2=0.95 and R2=0.94, respectively). The regression analyses suggest, however, different patterns for infants with low or high ponderal indices.

Anthropometry↗
PubMed2004

The ponderal index in triplets: III. Association with birth weight discordance.

Our objective was to determine the association of the ponderal index with birth weight discordance in triplets. We analyzed data from triplets delivered at 28-37 weeks for birth weight discordance (>25% difference between the heaviest and lightest triplet). Three categories of discordance (low skew, symmetrical, and high skew) were classified according to the relative position of the middle triplet. Birth weights and the ponderal index (birth weight/[length]3) of all concordant and discordant triplet groups were compared. Of 752 triplet sets included, 184 (24.5%) were discordant. Total triplet birth weight was higher in the concordant compared to all discordant categories. As opposed to birth weight, where only the middle triplet differed according to discordance pattern, the ponderal index for the largest triplet was significantly higher in the low skew discordant group compared to the concordant and other discordant triplet groups. In contrast, the ponderal index for the smallest and middle triplets were similar among the discordant groups. We concluded that discordance in triplet pregnancies exhibits different patterns of mass (birth weight) versus size (ponderal index). Our findings suggest that it may be the size of largest triplet that determines the presence or absence or discordance in triplet gestations.

Adult↗
PubMed2004

The ponderal index in triplets: IV. Relationship with maternal height.

The purpose of the study was to further evaluate the relationship between maternal height and neonatal ponderal index and length. A total of 774 triplet sets with matched maternal stature was available for analyses. We found a significant correlation between maternal height and infant length for both nulliparas (R2=0.70, p=0.04) and multiparas (R2=0.99, p=0.00005). The slopes of the regressions were different than zero, but the difference between the respective regressions was not significant (p=0.83). The analysis revealed a significant correlation between infant ponderal index and maternal stature for nulliparas (R2=0.68, p=0.04) but not for the multiparas (R2=0.08, p=0.6). The slope of the regression for nulliparas was different than zero, but that for the nulliparas was not. The difference between the respective regressions was significant (p=0.03). We conclude that taller mothers deliver longer infants, irrespective of parity, whereas the effect of maternal height on the ponderal index is parity-dependent.

Anthropometry↗
PubMed2004

Triplet pregnancies in women aged 40 or older: a matched control study.

OBJECTIVE: To determine, in triplet pregnancies, if maternal age is associated with adverse outcome in terms of birth weight characteristics. STUDY DESIGN: We analyzed a nationwide cohort of live-born triplets compiled by Matria Healthcare (Marietta, Georgia). We compared all 171 mothers > or = 40 years old with randomly selected and matched-for-parity mothers aged 25-29 and 35-39 years. The main outcome measures were length of gestation and individual and total triplet birth weight. All the subjects had private health insurance. The sample size was adequate to detect 5% differences at a power of 80%. RESULTS: Birth weights for infants A, B and C were significantly higherfor mothers > or = 40 years (P = .016, .01, and .03, respectively); total triplet birth weight was significantly higher as compared with that in the younger controls (P =.01). Gestational ages were similar in the 3 groups. In addition, the frequencies of births at < 28 weeks and of < 1,000 g were reduced by one-third or more in women aged 40 or older as compared to the younger controls (2.3% vs. 6.4% and 4.5% vs. 7.0%, respectively). CONCLUSION: Older mothers of triplets have better outcomes than do their younger counterparts in terms of total triplet birth weight.

Adult↗
PubMed2003

A novel approach to intertriplet birth weight discordance.

OBJECTIVE: This study was undertaken to evaluate intertriplet birth weight discordance. STUDY DESIGN: Birth weight discordance greater than 25% was evaluated in a cohort of 2804 US live-born triplets. Symmetric and high- and low-skew sets were defined by the rank of the middle triplet between the heavier and the lighter triplets. Frequencies of discordance level and type were analyzed by gestational age, parity, and total triplet birth weight. RESULTS: Discordance of 25.1% to 35% and greater than 35% was found in 19.4% and 9.5% of the triplets analyzed, respectively. Frequencies of greater than 25% discordant sets demonstrated polynomial relationship to gestational age (R (2) = 0.94, P <.001) total triplet birth weight deciles (R (2) = 0.97, P <.001). Frequencies of discordance type are unchanged throughout gestation. CONCLUSION: Birth weight discordance in triplets is frequent and large and implies exhaustion of fetal growth potential despite a uterine environment that appears to perform at maximal effort in these pregnancies.

Birth Weight↗
PubMed2003

Outcome of triplets and high-order multiple pregnancies.

PURPOSE OF REVIEW: To present data related to the outcome of triplets and high-order multiple pregnancies. RECENT FINDINGS: Current frequencies of high-order multiple pregnancies in most developed countries range between 400 and 800% above the rates observed in the late 1970s. Of particular importance is the striking increase in pregnancies in older mothers. These epidemiological trends are the result of modern infertility treatments. The improved outcome of triplets may be attributed to close antenatal and perinatal care, both of which are more likely to be implemented in patients who can afford treatment for infertility. The overall odds of delivering at least one triplet infant weighing less than 1000 g is approximately 10%. The neonatal complications among triplets weighing less than 1500 g at birth are not much different from those among twins or singletons, except for a higher neonatal mortality rate. Despite this, the frequency of cerebral palsy bears a significant exponential relationship to the number of fetuses, and iatrogenic multiple births are clearly implicated in the increased cerebral palsy rate. In the past few years the perinatal mortality rate for triplets has been approximately 110/1000, three-quarters of which represent neonatal deaths. SUMMARY: Available data imply that in order to improve outcomes further, all multiple pregnancies deserve optimal perinatal care, something that is not always obtainable.

Adult↗
PubMed2003

Effect of maternal height on gestational age and birth weight in nulliparous mothers of triplets with a normal pregravid body mass index.

OBJECTIVE: To study the effect of maternal height on gestational age and birth weight of triplets born to nulliparous women with a normal pregravid body mass index (BMI). STUDY DESIGN: A 1988-2000 prospective cohort of 1,219 U.S. live-born triplets was evaluated. Patients were grouped into stature categories of 5-cm intervals. Mean values for BMI, height, maternal age, gestational age at birth, total triplet birth weight and frequencies of births at < 28 weeks and with very low birth weight were calculated for each height category. RESULTS: Maternal heights were normally distributed (mean, 165.2 +/- 6.2 cm). We found a significant positive correlation (R2 = .95), different from a zero slope (P < .01), between mean total triplet birth weight and height category. Nulliparous women who were taller than 165 cm had age, BMI and gestational age characteristics similar to those of their shorter counterparts but delivered significantly heavier triplets and were at significantly lower risk of delivering very-low-birth-weight triplets. CONCLUSION: Taller women are more likely to deliver heavier triplets and are at lower risk of delivering very-low-birth-weight triplets. This information should be included in counseling women with the potential of conceiving triplets.

Adult↗
PubMed2002

Iatrogenic multiple pregnancy.

Iatrogenic - physician-made - multiple pregnancies (IMPs) significantly contribute to the epidemic of twins and high-order multiples in most developed and in many developing countries. The primary etiology for IMPs is treatment of reduced fecundity, some but not all of which is associated with specific lifestyle changes of women in the second half of the 20th century. IMPs contribute to increased perinatal morbidity and mortality related to prematurity and low birth weights. In addition, the use of assisted conception techniques increases the frequency of monozygotic twinning and related pathology. Because assisted conceptions are costly interventions, current numbers of IMPs represent a balance between the need to maximize success rates and the desire to minimize the untoward outcome rates. We believe that eliminating procedures associated with unavoidable IMPs and controlling the number of transferred embryos can achieve a significant reduction in the adverse perinatal outcomes and costs associated with IMPs.

Adult↗
PubMed2002

Total and individual triplet birth weights as a function of gestational age.

OBJECTIVE: Our purpose was to determine the relationship between gestational age and both the total and individual triplet birth weights. STUDY DESIGN: A 1988-2000 prospective cohort of 3238 live-born triplets in the United States was evaluated. The mean individual (heaviest, middle, and lightest) and total triplet birth weights were correlated with gestational age in nulliparous and multiparous patients. RESULTS: The mean total triplet birth weights significantly correlated with gestational age for both nulliparous women and multiparous women, but the respective regression lines were significantly different (P =.0018). The respective regression lines for individual triplets showed a significant linear correlation (R(2) = 0.996-0.998). Interparity and intraparity differences of the individual triplets' regression lines were also significantly different. CONCLUSIONS: The relationships support a model of two distinct growth periods for triplets: an age- and growth-promoting period until 33 weeks and an age-promoting growth-restricting period thereafter.

Adult↗
PubMed2002

The Northwestern Twin Chorionicity Study: I. Discordant inflammatory findings that are related to chorionicity in presenting versus nonpresenting twins.

OBJECTIVE: The purpose of this study was to evaluate the association between chorionicity and discordant chorioamnionitis and funisitis in twin gestations. STUDY DESIGN: This was a retrospective analysis of 1156 twin placentas with a standardized diagnosis of chorionicity, chorioamnionitis, and funisitis for comparison between presenting and nonpresenting twins with dichorionic-separate, dichorionic-fused, and monochorionic placentas. RESULTS: Frequencies of chorioamnionitis in the nonpresenting twin were significantly lower in dichorionic placentas (odds ratio, 0.4; 95% CI, 0.3, 0.6, in dichorionic-separate placentas; odds ratio, 0.5; 95% CI, 0.3, 0.8, in dichorionic-fused placentas) compared with monochorionic placentas. The frequency of advanced inflammation (ie, chorioamnionitis with funisitis) was significantly lower in the nonpresenting twin than in the presenting twin, but only in dichorionic-separate placentas (odds ratio, 0.2; 95% CI, 0.1, 0.4). CONCLUSION: Dichorionic placentas confer significant protection against the spread of chorioamnionitis from the presenting to the nonpresenting gestational sac. In the more advanced process that involves the umbilical cord, only the subset of separate dichorionic placentas confers this protective effect against the spread of inflammation.

Adult↗
PubMed2002

The odds of delivering one, two or three extremely low birth weight (< 1000 g) triplet infants: a study of 3288 sets.

The odds of an individual triplet pregnancy to end with neonates weighing < 1000 g (extremely low birth weight [ELBW]) are unknown. We analyzed a nationwide perinatal database collected by Matria Healthcare, Inc. (Marietta, GA) to select from 3288 triplets those weighing 500-1000 g, delivered during the period 1988-2000 in the United States. We counted the number of sets with one, two, and three ELBW neonates and compared the incidence of ELBW infants between the subsets of nulliparas and multiparas. The odds of delivering at least one ELBW infant was significantly higher among nulliparas (1:8) than among multiparas (1:14), Odds Ratio (OR) 1.9, 95% Confidence Interval (CI) 1.9, 2.5. The odds of having at least two ELBW sibs in nulliparas (1:16) is twice higher than in multiparas (1:31), OR 2.0, 95% CI 1.3, 2.9. Nulliparas and multiparas had similar odds of delivering three ELBW infants (1:29 versus 1:40, OR 1.3, 95% CI 0.9, 2.1). Nulliparas are at significantly increased risk of delivering one or two ELBW triplets. This observation is no less than alarming and highlighted by the exceptionally high risk of major neurological deficits reported among ELBW infants.

Adult↗
PubMed2002

Hypertensive disease in twin pregnancies: a review.

Reports over the past seventy years show that twin gestations lead to an increased risk of hypertensive disorders. Numerous studies discuss the incidence of hypertensive disease in twin versus singleton gestations, as well as effects of parity, race, age, income level, smoking, zygosity and heritability on this condition. The range of relative risk of gestational hypertension, preeclampsia and eclampsia for twin compared to singleton gestations is 1.2 to 2.7, 2.8 to 4.4 and 3.4 to 5.1 respectively. Parity, African-American ethnicity, and young maternal age are all factors that increase the relative risk of acquiring hypertensive disease to 4.0, 1.8 and 1.5 in mothers of twin gestations. Factors such as maternal smoking, income level and zygosity have a negligible effect on the relative risk of acquiring hypertensive disease in twin gestations. In addition to twin mothers exhibiting a higher incidence of hypertensive disease compared to their singleton counterparts, they also exhibit an earlier onset of hypertensive disease at both 35 and 37 weeks of gestation comparatively. Uric acid levels measured at 30-31 weeks of gestation in twin mothers predicted the onset of preeclampsia with a sensitivity of 73% and a specificity of 74%. The range of risks presented in the literature is wide and the therapies avocated are diverse. We therefore decided to summarize the risks in a comparative fashion and to review current therapeutic strategies for the convenience of clinicians who confront increasing numbers of multiple pregnancies. The tables bring all recent published risks together in the first comparative analysis in which the data has been converted to relative risks and confidence intervals. Because the literature is relatively silent on specific management of hypertensive disease in twin pregnancies, general management recommendations for singleton gestations should be used by practitioners caring over twin gestations.

Eclampsia↗
PubMed2002

Triplet births in the United States. An epidemic of high-risk pregnancies.

OBJECTIVE: To more precisely understand the changes in triplet births in recent years. STUDY DESIGN: Analysis of recent government and medical publications pertaining to triplets. RESULTS: Triplet births are at much greater risk than singletons of poor birth outcomes. More than 9 of 10 triplet births are born preterm (< 37 completed weeks of gestation) as compared with < 1 of 10 singleton infants. The average weight of a triplet newborn (1,698 g) is one-half that of a singleton newborn (3,358 g). The infant death rate for triplet and other higher-order multiple births is 12 times higher than that for singletons (93.7 as compared with 7.8 infant deaths per 1,000 live births). CONCLUSION: Based on their frequency of preterm birth, low birth weight and infant death rate, it is appropriate to characterize all triplet pregnancies as high risk.

Adult↗
PubMedDate not supplied

Are mammography and palpation sufficient for breast cancer screening? A dissenting opinion.

Breast cancer is an equal opportunity killer in that as many as 60%-70% of breast cancer patients have no obvious risk factor(s). Thus, the continued reliance on the importance of risk factors to initiate screening programs may inhibit further inquiry into better diagnostic and prognostic indicators. An extensive review of past and recent literature reveals that mammography is not an objective examination. Its use as a screening tool is facilitated among women 40 years old and older whose breast tissue is primarily fatty and provides better visualization. Younger women are not generally advised to use mammography because of its potentially hazardous effects associated with repeated use of radiation. More importantly, regardless of patient age, radiologists interpret mammograms, and different degrees of interpretation error exist for different radiologists as well as for the same radiologist performing the analysis after a period of time. Thus, the use of mammography as the sole screening tool does not provide patients or physicians with a sense of confidence about sensitivity and specificity. Further, recent enthusiasm to promote mammography screening may give women unrealistic expectations, leading them to falsely believe that a negative examination is assurance that cancer is not present in its earliest detectable stage. We propose to supplement the physical examination and mammography with a third screening modality based on thermal detection monitors. This is a noninvasive and nonradiogenic tool and might enable clinicians to provide patients with every opportunity for early diagnosis.

Adult↗