An evolutionary perspective on the association between grandmother-mother relationships and maternal mental health among a cohort of pregnant Latina women

Grandmothers are often critical helpers during a mother's reproductive career. Studies on the developmental origins of health and disease demonstrate how maternal psychological distress can negatively influence fetal development and birth outcomes, highlighting an area in which soon-to-be grandmothers (henceforth “grandmothers”) can invest to improve both mother and offspring well-being. Here, we examine if and how a pregnant woman's mental health– specifically, depression, state-anxiety, and pregnancy-related anxiety– is influenced by her relationship with her fetus' maternal and paternal grandmother, controlling for relationship characteristics with her fetus' father. In a cohort of pregnant Latina women in Southern California (N = 216), we assessed social support, geographic proximity, and communication between the fetus' grandmothers and pregnant mother. We assessed maternal mental health with validated questionnaire-based instruments. We find that both social support from and communication with the maternal grandmother were statistically associated with less depression, while no paternal grandmother relationship characteristics were statistically significant in association with any mental health variable. These results align with the idea that maternal grandmothers are more adaptively incentivized to invest in their daughters' well-being during pregnancy than paternal grandmothers are for their daughters-in-law. Results suggest that the positive association of maternal grandmothers with mothers' mental health may not hinge on geographic proximity, but rather, potentially function through emotional support. This work represents a novel perspective describing a psychological and prenatal grandmaternal effect.     

Family networks in prenatal and postnatal health

This paper examines the effects of kin access on prenatal health practices, birth outcome, and postnatal health practice for infants born to black and white mothers ages 21 to 28 in the U.S. during 1984-86. The data used for this research were compiled from three sources: (1) The National Longitudinal Survey of Youth; (2) The Children of the National Longitudinal Survey of Youth; (3) special kin access data files, which were created specifically for this study. Logistic regression procedures are used to assess the effects of kin proximity, maternal grandmother proximity, and presence of the child's father on health practices (N = 1,030) and birth outcome (N = 1,385), controlling for the mother's educational attainment, work experience, poverty, presence of the child's father, and birth order of the child. We find no evidence supporting the notion that kin access positively affects the prenatal and postnatal health practices of young mothers. The results suggest that young mothers who reside with their mothers or other adult kin, and those who are in close proximity to them, are no more likely to seek prenatal care during the first trimester, or to avoid smoking or drinking during pregnancy. Mothers who live with a sexual partner or husband are, however, somewhat more likely to seek prenatal care and to avoid alcohol use during pregnancy. Closer kin access is associated with a lower probability of breastfeeding. These results suggest that it will not be adequate to rely on kin networks or kin assistance to improve the prospect of healthy birth outcomes.     

Family networks in prenatal and postnatal health

Abstract

This paper examines the effects of kin access on prenatal health practices, birth outcome, and postnatal health practice for infants born to black and white mothers ages 21 to 28 in the U.S. during 1984–86. The data used for this research were compiled from three sources: (1) The National Longitudinal Survey of Youth; (2) The Children of the National Longitudinal Survey of Youth; (3) special kin access data files, which were created specifically for this study. Logistic regression procedures are used to assess the effects of kin proximity, maternal grandmother proximity, and presence of the child's father on health practices (N = 1,030) and birth outcome (N = 1,385), controlling for the mother's educational attainment, work experience, poverty, presence of the child's father, and birth order of the child. We find no evidence supporting the notion that kin access positively affects the prenatal and postnatal health practices of young mothers. The results suggest that young mothers who reside with their mothers or other adult kin, and those who are in close proximity to them, are no more likely to seek prenatal care during the first trimester, or to avoid smoking or drinking during pregnancy. Mothers who live with a sexual partner or husband are, however, somewhat more likely to seek prenatal care and to avoid alcohol use during pregnancy. Closer kin access is associated with a lower probability of breastfeeding. These results suggest that it will not be adequate to rely on kin networks or kin assistance to improve the prospect of healthy birth outcomes.     

Infant Handling and Maternal Response in Japanese Macaques

We focused on the social interactions of infant Japanese macaques (Macaca fuscata) and on the protective response of their mothers to such interactions. Infant social interactions included: received allomaternal behavior (positive infant handling), hand touch and inspection (neutral handling), and aggression (negative handling) as well as social play. Maternal protective responses included aggression to the infant's interactant and restraining or retrieving the infant. All types of social interactions as well as the maternal response to such interactions showed clear developmental variations. Frequency of infant social interactions and maternal protective responses also showed large interindividual variability. Juvenile and subadult females without maternal experience were the most frequent infant handlers. Infants received positive handling primarily from their kin, while mothers were equally protective in response to positive handling received by kin and by non-kin. Conversely, kin showed higher levels of neutral handling and their interest was more easily tolerated by mothers compared to that of non-kin.     

Explaining variation in maternal care in a cooperatively breeding mammal

Because of the necessity of lactation, mammalian mothers must perform at least a minimum amount of infant care. In cooperatively breeding species, other group members aid in all other aspects of infant care. However, some mothers continue to carry and nurse their infants more than others. The golden lion tamarin, Leontopithecus rosalia, is a small, communally breeding primate in the family Callitrichidae. We studied hormonal, individual, historical and social factors hypothesized to contribute to variation in levels of maternal care. We used neonatal weight as a measure of prenatal care, and carrying and nursing as measures of postnatal care. Greater neonatal weight was associated with smaller litter size, lower prepartum levels of oestrogen conjugates, and higher prepartum cortisol levels. Higher rates of carrying during weeks 2 and 3 were associated with higher maternal weight, larger litter size and smaller numbers of helpers per infant. Higher rates of nursing in weeks 2 and 3 were predicted by smaller group size and provisioning of the mother. The most important factors affecting postnatal maternal care were maternal weight, group size, litter size and provisioning status of the mother. Thus, females that display higher levels of maternal care do so either because they have to (they have fewer helpers) or because they can (they are in better condition).     

Social behavior of infant and mother Japanese Macaques (Macaca fuscata): Effects of kinship,partner sex,and infant sex

The behavioral interactions of 22 infant and mother Japanese macaques with other group members were studied. Focal-animal observations were made from the time of each infant’s birth until 1 year of age. Infants and mothers both displayed exceedingly strong preferences for associating with matrilineal kin and, specifically, for female kin. The degree of genetic relatedness was positively correlated with levels of spatial proximity, contact, grooming, aggression, and play. Overall frequencies of interactions with nonkin were very low, and partner sex was not an important factor in interactions with nonkin. There were no significant differences between male and female infants in interactions with kin versus nonkin. There was only one significant difference between male and female infants in interactions with males versus females: female infants showed stronger preferences for initiating proximity with females over males than did male infants. Because mothers provide the focal point for infant interactions during the first year of life, we compared the behavior of infants and mothers. Mothers were the recipients of more social interactions than were infants, mothers engaged in more grooming than did infants, and infants engaged in more social play than did mothers. These findings are only partially consistent with kin-selection theory, and the inadequacies of studying matrilineal kin discrimination to test kin selection are reviewed. The near-absence of infant sex differences in associations with social partners suggests that although maternal kin other than the mother are important to infant socialization, they probably do not contribute to the development of behavioral sex differences until after the first year of life.     

Maternal trade-off in treating high-risk children

Low birthweight and the infant's health status are expected to strongly influence the child's reproductive value and, thus, the maternal decisions on the amount and timing of investment. A total of 590 Hungarian primiparous mothers giving birth in the late 1980s were recruited for the longitudinal study. Mothers of high-risk infants shortened the duration of breast-feeding and interbirth intervals, compared to those with an infant of higher survival prospects. The most powerful predictor of the length of the lactation period was the infant's weight at birth, whereas birth spacing was significantly influenced by the health status of the older child. Socioeconomic status had a positive effect on maternal care as well, but it did not change the basic pattern of diminishing maternal care as a function of the infants' low reproductive value. The combination of the above factors resulted in a cumulative effect on maternal investment of mothers with handicapped children of various degrees of risk. An attempt has been made to exclude alternative explanations and to discuss the proximate mechanisms of discriminative parental solicitude.     

Maternal residential proximity to nuclear facilities and low birth weight in offspring in Texas

Health effects of close residential proximity to nuclear facilities have been a concern for both the general public and health professionals. Here, a study is reported examining the association between maternal residential proximity to nuclear facilities and low birth weight (LBW) in offspring using data from 1996 through 2008 in Texas, USA. A case–control study design was used together with a proximity-based model for exposure assessment. First, the LBW case/control births were categorized into multiple proximity groups based on distances between their maternal residences and nuclear facilities. Then, a binary logistic regression model was used to examine the association between maternal residential proximity to nuclear facilities and low birth weight in offspring. The odds ratios were adjusted for birth year, public health region of maternal residence, child’s sex, gestational weeks, maternal age, education, and race/ethnicity. In addition, sensitivity analyses were conducted for the model. Compared with the reference group (more than 50 km from a nuclear facility), the exposed groups did not show a statistically significant increase in LBW risk [adjusted odds ratio (aOR) 0.91 (95% confidence interval (CI): 0.81, 1.03) for group 40–50 km; aOR 0.98 (CI 0.84, 1.13) for group 30–40 km; aOR 0.95 (CI 0.79, 1.15) for group 20–30 km; aOR 0.86 (CI 0.70, 1.04) for group 10–20 km; and aOR 0.98 (CI 0.59, 1.61) for group 0–10 km]. These results were also confirmed by results of the sensitivity analyses. The results suggest that maternal residential proximity to nuclear facilities is not a significant factor for LBW in offspring.     

Reproductive health among married and unmarried mothers aged less than 18, 18–19, and 20–24 years in the United States, 2014–2019: A population-based cross-sectional study

BackgroundStudies in low- and middle-income regions suggest that child marriage (<18 years) is a risk factor for poor reproductive outcomes among women. However, in high-income-country contexts where childbearing before age 18 occurs predominantly outside marriage, it is unknown whether marriage is adversely associated with reproductive health among mothers below age 18. This study examined the joint associations of marriage and adolescent maternal age group (<18, 18–19, and 20–24 years) with reproductive, maternal, and infant health indicators in the United States.Methods and findingsBirth registrations with US resident mothers aged ≤24 years with complete information on marital status were drawn from the 2014 to 2019 Natality Public Use Files (n = 5,669,824). Odds ratios for the interaction between marital status and maternal age group were estimated using multivariable logistic regression, adjusting for covariates such as maternal race/ethnicity and nativity status, federal program participation, and paternal age. Marriage prevalence was 3.6%, 13.2%, and 34.1% among births to mothers aged <18, 18–19, and 20–24 years, respectively. Age gradients in the adjusted odds ratios (AORs) were present for most indicators, and many gradients differed by marital status. Among births to mothers aged <18 years, marriage was associated with greater adjusted odds of prior pregnancy termination (AOR 1.64, 95% CI 1.52–1.77, p < 0.001), repeat birth (AOR 2.84, 95% CI 2.68–3.00, p < 0.001), maternal smoking (AOR 1.24, 95% CI 1.15–1.35, p < 0.001), and infant morbidity (AOR 1.07, 95% CI 1.01–1.14, p = 0.03), but weaker or reverse associations existed among births to older mothers. For all maternal age groups, marriage was associated with lower adjusted odds of late or no prenatal care initiation, sexually transmitted infection, and no breastfeeding at hospital discharge, but these beneficial associations were weaker among births to mothers aged <18 and 18–19 years. Limitations of the study include its cross-sectional nature and lack of information on marriage timing relative to prior pregnancy events.ConclusionsMarriage among mothers below age 18 is associated with both adverse and favorable reproductive, maternal, and infant health indicators. Heterogeneity exists in the relationship between marriage and reproductive health across adolescent maternal age groups, suggesting girl child marriages must be examined separately from marriages at older ages.

In a population-based study, Andrée-Anne Fafard St-Germain and colleagues examine the joint associations of marriage and adolescent maternal age group (<18, 18-19, and 20-24 years) with reproductive, maternal, and infant health indicators in the United States.     

You’ll never walk alone – The effects of walkability on pregnancy behaviors and outcomes

This study investigates the relationship between local walkability and physical activity and subsequent health outcomes among pregnant women – for whom walking is the recommended, and by far most common, form of exercise. Using an EPA measure of walkability at the county level (as well as other county-level characteristics) combined with rich individual-level data on pregnant women yields evidence that higher walkability translates into improvements in maternal and infant health outcomes as well as physical activity. Using the 2011 Natality Detail Files with geographic identifiers and controlling for the overall health of women in the community as well as the individual mother’s pre-pregnancy BMI, we show that women residing in more walkable counties are less likely to experience preterm birth, low birth weight, gestational diabetes and hypertension. While one potential mechanism is through improved gestational weight gain, the evidence points to more general improvements in health as walkability does not seem to prevent excessive weight gain or macrosomic babies. Evidence that these general improvements derive at least in part from greater physical activity comes from analyses using the 2011 Behavioral Risk Factor Surveillance System, in which higher walkability translates into more physical activity among pregnant women (and also relative to their non-pregnant counterparts). Our study suggests more broadly that pregnant women’s physical activity responds to factors that facilitate it and that such activity makes a difference to birth outcomes.     

First report of alloparental care in the Key Largo woodrat (Neotoma floridana smalli)

Here we report the first observation of alloparental care in a subadult female Key Largo woodrat. Maternal and other behaviors were scored for the subject dam and her subadult daughter at the birth of the dam’s second litter and the following 30 days. After assisting with birth, the subadult exhibited maternal behaviors and remained in close proximity to the pups. The rate of maternal care behaviors observed in the subject dam was lower than in solitary dams without an alloparent present. However, the total maternal care score for the dam and subadult combined approached the average score for single dams.     

Effects of motherhood on physiological and subjective responses to infant cries in teenage mothers: a comparison with non-mothers and adult mothers

The present study was designed to determine whether becoming a mother during the adolescent period changes maternal responsiveness or maternal motivation, assessed through hormonal, autonomic, and hedonic responses to recorded infant cries and interactions with their babies. Fifty-six teen mothers were compared to 58 teen non-mothers and 49 adult mothers. Teen mothers reported more sympathy and alertness in response to recorded infant cries compared to non -mother teens; however, among the teen women there were no differences between mothers and non-mothers in heart rate and cortisol responses to infant cries. In contrast, in comparison to adult mothers, teen mothers reported the same levels of sympathy and alertness to infant cries; however, adult mothers showed an 'alerted' pattern of heart rate and cortisol response to infant cries not seen in the teen mother group. Inclusion of the covariate, fathers' employment classification as an index of SES or time of testing and cortisol sampling did not affect this pattern of results. Taken together, these results show that where self-report is used as a measure of maternal responsiveness, teen mothers are no different in responsiveness than adult mothers; however, where physiological and interactional measures of responsiveness are considered, teen mothers are less likely to show heightened or selective responses to infant cries or respond 'attentively' to the infant.     

Changes in yearling rhesus monkeys' relationships with their mothers after sibling birth

The birth of a new sibling is believed to signify an abrupt and important transition in a young primate's relationship with its mother-one that is of potential importance from at least three theoretical perspectives: attachment theory, parent-offspring conflict theory, and dynamic assessment models. This study examines changes in relationships between free-ranging yearling rhesus monkeys (Macaca mulatta) and their mothers concomitant with the birth of the mother's next infant, and tests predictions derived from each theoretical perspective. We observed 31 yearling rhesus on Cayo Santiago, Puerto Rico, 3 months before and 3 months after their siblings' births, using focal animal sampling methods. Changes in measures related to mother-yearling interaction and yearling distress were examined using repeated-measures analysis of variance. After sibling birth, mothers and yearlings abruptly reduced amounts of time in contact and increased amounts of time at a distance and out of sight of one another. Mothers and yearlings played approximately equal roles in bringing about decreases in proximity, and yearlings took the primary roles in bringing about decreases in contact. Rates of maternal aggression toward yearlings increased immediately and markedly after birth, possibly providing yearlings with early cues regarding subsequent decreased levels of maternal care. There were no marked increases in overt signs of yearling distress (e.g., vocalizations or tantrums) following the births. We conclude that yearlings generally acquiesced to reduced levels of care, responding behaviorally with increased independence and maturity. In this sense, our study provides preliminary support for dynamic assessment models over attachment theory and parent-offspring conflict theory models.     

The development of behavioural sex differences in infant rhesus macaques (Macaca mulatta)

Studies of infant rhesus macaques have generally reported sex differences in the frequency of expression of some behaviour patterns, such as rough-and-tumble play and socio-sexual mounting. In contrast, sex differences in other behaviour patterns, such as proximity to the mother, have been less consistantly reported. Using data on the behavioural development of infant rhesus macaques living in captive social groups, we have attempted to provide further evidence for, or against, sex differences in behaviour and to investigate the possible influence of maternal rank and parity on sex differences in infant behaviour and mother-infant interactions. The behaviour of 14 male and 20 female infants and their mothers was studied during the first six months of life, including measures of play behaviour socio-sexual mounting, and mother-infant interactions. Our data reveal that, on average, male infants exhibited more rough-and-tumble play and mounting than female infants, and also exhibited stationary play, chasing play, and initiated play more frequently than females. Such sex differences appear to be robust in macaques and have been reported in a variety of housing conditions. male and female infants did not differ in the amount of time spent at particular distances from their mothers, and mothers were not found to behave differently towards sons and daughters, using measures of restraint, rejection, and grooming. These results are in contrast to previous studies on singly-housed mother-infant pairs but similar to those on free-ranging populations. Mothers did behave differently towards their infants depending upon the mother's rank and previous number of offspring. These maternal characteristics may have significant consequences for the behavioural development of both male and female infant primates.     

Developmental and evolutionary assumptions in a study about the impact of premature birth and low income on mother–infant interaction

In order to study the impact of premature birth and low income on mother–infant interaction, four Portuguese samples were gathered: full-term, middle-class (n = 99); premature, middle-class (n = 63); full-term, low income (n = 22); and premature, low income (n = 21). Infants were filmed in a free play situation with their mothers, and the results were scored using the CARE Index. By means of multinomial regression analysis, social economic status (SES) was found to be the best predictor of maternal sensitivity and infant cooperative behavior within a set of medical and social factors. Contrary to the expectations of the cumulative risk perspective, two factors of risk (premature birth together with low SES) were as negative for mother–infant interaction as low SES solely. In this study, as previous studies have shown, maternal sensitivity and infant cooperative behavior were highly correlated, as was maternal control with infant compliance. Our results further indicate that, when maternal lack of responsiveness is high, the infant displays passive behavior, whereas when the maternal lack of responsiveness is medium, the infant displays difficult behavior. Indeed, our findings suggest that, in these cases, the link between types of maternal and infant interactive behavior is more dependent on the degree of maternal lack of responsiveness than it is on birth status or SES. The results will be discussed under a developmental and evolutionary reasoning.     

Equality in Maternal and Newborn Health: Modelling Geographic Disparities in Utilisation of Care in Five East African Countries

BackgroundGeographic accessibility to health facilities represents a fundamental barrier to utilisation of maternal and newborn health (MNH) services, driving historically hidden spatial pockets of localized inequalities. Here, we examine utilisation of MNH care as an emergent property of accessibility, highlighting high-resolution spatial heterogeneity and sub-national inequalities in receiving care before, during, and after delivery throughout five East African countries.MethodsWe calculated a geographic inaccessibility score to the nearest health facility at 300 x 300 m using a dataset of 9,314 facilities throughout Burundi, Kenya, Rwanda, Tanzania and Uganda. Using Demographic and Health Surveys data, we utilised hierarchical mixed effects logistic regression to examine the odds of: 1) skilled birth attendance, 2) receiving 4+ antenatal care visits at time of delivery, and 3) receiving a postnatal health check-up within 48 hours of delivery. We applied model results onto the accessibility surface to visualise the probabilities of obtaining MNH care at both high-resolution and sub-national levels after adjusting for live births in 2015.ResultsAcross all outcomes, decreasing wealth and education levels were associated with lower odds of obtaining MNH care. Increasing geographic inaccessibility scores were associated with the strongest effect in lowering odds of obtaining care observed across outcomes, with the widest disparities observed among skilled birth attendance. Specifically, for each increase in the inaccessibility score to the nearest health facility, the odds of having skilled birth attendance at delivery was reduced by over 75% (0.24; CI: 0.19–0.3), while the odds of receiving antenatal care decreased by nearly 25% (0.74; CI: 0.61–0.89) and 40% for obtaining postnatal care (0.58; CI: 0.45–0.75).ConclusionsOverall, these results suggest decreasing accessibility to the nearest health facility significantly deterred utilisation of all maternal health care services. These results demonstrate how spatial approaches can inform policy efforts and promote evidence-based decision-making, and are particularly pertinent as the world shifts into the Sustainable Goals Development era, where sub-national applications will become increasingly useful in identifying and reducing persistent inequalities.     

Birth Timing and Behavioral Responsiveness Predict Individual Differences in the Mother–Infant Relationship and Infant Behavior During Weaning and Maternal Breeding

There is a great deal of variability in mother–infant interactions and infant behavior across the first year of life in rhesus monkeys. The current article has two specific aims: (1) to determine if birth timing predicts variability in the mother–infant relationship and infant behavior during weaning and maternal breeding, and (2) to identify predictors of infant behavior during a period of acute challenge, maternal breeding. Forty‐one mother–infant pairs were observed during weaning when infants were 4.5 months old, and 33 were followed through maternal breeding. Subjective ratings of 16 adjectives reflecting qualities of maternal attitude, mother–infant interactions, and infant attitude were factor analyzed to construct factors relating to the mother–infant relationship (Relaxed and Aggressive) and infant behavior (Positive Engagement and Distress). During weaning, late born infants were more Positively Engaged than peak born infants (ANOVA, P < 0.05); however, birth timing did not affect the mother–infant relationship factors Relaxed and Aggressive or the infant attitude factor Distress. During maternal breeding, early born infants had less Relaxed relationships with their mothers than peak or late born infants, higher Positive Engagement scores than peak or late born infants, and tended to have higher Distress scores than peak born infants (repeated‐measures ANOVA, P < 0.05). In addition, Distress scores were higher during maternal breeding than during the pre‐ and postbreeding phases. Finally, multiple regression (P < 0.05) indicated that while infant behavioral responsiveness predicted infant Positive Engagement during the acute challenge of maternal breeding, qualities of the mother–infant relationship predicted infant Distress. These data suggest that birth timing influences the patterns of mother–infant interactions during weaning and maternal breeding. Additionally, infant behavioral responsiveness and mother–infant relationship quality impact infant social engagement and affect expression, respectively. Am. J. Primatol. 74:734‐746, 2012. © 2012 Wiley Periodicals, Inc.     

Maternal Anxiety in Rhesus Macaques (Macaca mulatta)

Visual monitoring and scratching were used as behavioral indicators of maternal and social anxiety in small captive groups of rhesus macaques. Young infants were especially at risk from other group members during the first weeks of locomotion away from their mothers. Mothers received aggression from other individuals irrespective of their infants' presence or absence. The rate at which mothers scratched themselves increased significantly when their infants moved away from them and when the infants approached or were approached by individuals who frequently harassed them. The rate of maternal scratching and the rate of glancing at the infant and at other individuals when the infant was away decreased as infants grew older and became less vulnerable to harassment. In contrast, the rate of maternal scratching and visual monitoring of other individuals when the infant was in contact remained stable across the first 12 wk of lactation. The rate of maternal scratching increased when the mother-infant pair was in spatial proximity to the adult male or higher ranking adult females. Although visual monitoring and scratching showed a similar sensitivity to social variables, it is speculated that they might reflect different components of anxiety, namely, anticipation of danger and uncertainty due to motivational conflict. The results of this investigation indicate that a macaque mother's emotional reactivity to a perceived danger for herself and her infant can be measured quite accurately using the rates of visual monitoring and scratching and that the latter represent reliable tools to investigate the emotional correlates of maternal behavior in nonhuman primates.     

Adolescent mothers, stress, and prevention

Adolescent mothers face problems that can lead to psychological stress. Based on prospective data from the present study, these problems point toward the need for a coping skills prevention approach to help adolescent mothers manage stress. This paper reports data from outcome research on such an approach with adolescent mothers. Subjects were 79 adolescent mothers who were tested before, immediately after, and three months following the provision of coping skills intervention in an experimental condition. Subjects in a test-only control condition received no special intervention. At posttest, experimental condition subjects showed more positive outcomes on measures of social support, cognitive performance, conflict management, and interpersonal competence. At three-month follow-up, experimental condition subjects had more positive outcomes on social support, cognitive performance, parenting ability, child care self-efficacy, and measures of psychological well-being.     

Perinatal Outcomes and Unconventional Natural Gas Operations in Southwest Pennsylvania

Unconventional gas drilling (UGD) has enabled extraordinarily rapid growth in the extraction of natural gas. Despite frequently expressed public concern, human health studies have not kept pace. We investigated the association of proximity to UGD in the Marcellus Shale formation and perinatal outcomes in a retrospective cohort study of 15,451 live births in Southwest Pennsylvania from 2007–2010. Mothers were categorized into exposure quartiles based on inverse distance weighted (IDW) well count; least exposed mothers (first quartile) had an IDW well count less than 0.87 wells per mile, while the most exposed (fourth quartile) had 6.00 wells or greater per mile. Multivariate linear (birth weight) or logistical (small for gestational age (SGA) and prematurity) regression analyses, accounting for differences in maternal and child risk factors, were performed. There was no significant association of proximity and density of UGD with prematurity. Comparison of the most to least exposed, however, revealed lower birth weight (3323 ± 558 vs 3344 ± 544 g) and a higher incidence of SGA (6.5 vs 4.8%, respectively; odds ratio: 1.34; 95% confidence interval: 1.10–1.63). While the clinical significance of the differences in birth weight among the exposure groups is unclear, the present findings further emphasize the need for larger studies, in regio-specific fashion, with more precise characterization of exposure over an extended period of time to evaluate the potential public health significance of UGD.