Relative Importance of Maternal Constitutional Factors and Glucose Intolerance of Pregnancy in the Development of Newborn Macrosomia

The purpose of this case-control study was to determine the relative importance of various predictors of newborn macrosomia, with particular reference to maternal constitutional factors and glucose intolerance of pregnancy. Macrosomia was defined by both absolute birthweight ±4,000 g and birthweight ±90th centile for gestational age. One thousand mother/newborn pairs [209 macrosomic (cases) and 791 non-macrosomic newborns (controls)] were recruited. Mothers with pre-gestational diabetes mellitus were excluded. Data on prepregnancy and pregnancy variables were collected by review of prenatal, labour, and delivery and newborn assessment records and interview with the mother.

Predictors that entered the stepwise multiple regression model in order of significance were: previous history of macrosomia, increasing maternal weight, nonsmoking status, multiparity, male newborn gender, gestational age of 40–42 weeks, North American Aboriginal ethnicity, maternal birthweight >4,000 g, maternal height and maternal age >17 years. Glucose screen positive/100-g oral glucose tolerance test (GTT) negative status was a significant predictor for macrosomia as defined by birthweight greater than the 90th percentile for gestational age, but not for absolute birthweight over 4,000 g. It was the least significant of all the factors examined. Treated gestational diabetes was not a significant predictor.

By multivariate analysis, maternal constitutional factors are more powerful predictors of newborn macrosomia than maternal mild glucose intolerance. Treatment of mothers with GDM may be masking the effect of more pronounced carbohydrate intolerance.     

Prepregnancy body mass index is an independent risk factor for gestational hypertension,gestational diabetes,preterm labor,and small- and large-for-gestational-age infants

Objective: We examined if prepregnancy body mass index (BMI) is a risk factor for gestational hypertension, gestational diabetes, preterm labor, and small-for-gestational-age (SGA) and large-for-gestational-age (LGA) infants with consideration of gestational weight gain, to document the importance of preconception versus prenatal stage.

Methods: We used the data of 219?868 women from 2004 to 2011 Pregnancy Risk Assessment Monitoring System (PRAMS). Multivariate logistic regression analyses were performed to examine the effect of prepregnancy BMI for gestational hypertension, gestational diabetes, preterm labor, and SGA and LGA infants with consideration of gestational weight gain.

Results: Regardless of gestational weight gain, women with obese prepregnancy BMI (≥30?kg/m²) had increased odds of gestational hypertension (adjusted odds ratios (AOR)?=?2.91; 95% CI?=?2.76–3.07), gestational diabetes (2.78; 2.60–2.96), and LGA (1.87; 1.76–1.99) compared to women with normal prepregnancy BMI (18.5–24.9?kg/m²). Women with underweight prepregnancy BMI (<18.5?kg/m²) had increased odds of preterm labor (1.25; 1.16–1.36) and SGA infants (1.36; 1.25–1.49), but decreased odds of LGA infants (0.72; 0.61–0.85) in reference to women with normal prepregnancy BMI (18.5–24.9?kg/m²).

Conclusions: Regardless of adequacy of gestational weight gain, the risk of gestational hypertension, gestational diabetes, and LGA infants increases with obese prepregnancy BMI, whereas that of preterm labor and SGA infants increases with underweight prepregnancy BMI. Preconception care of reproductive aged women is as important as prenatal care to lower the risk of gestational hypertension, gestational diabetes, preterm labor, and SGA and LGA infants.     

Sex hormone-binding globulin levels and obesity in women with gestational diabetes: relationship with infant birthweight

Our objective was to determine whether sex hormone-binding globulin (SHBG) concentrations are associated with gestational diabetes mellitus (GDM) and whether this association is independent of prepregnancy body mass index (BMI). The relationship between maternal SHBG concentrations and birthweight in the offspring was also examined. The study included 47 women (20 with GDM, 27 controls). GDM screening and fasting serum SHBG measurements were performed at 26.1?±?3.7 weeks of pregnancy. A trend was observed for significantly lower SHBG concentrations in GDM patients (179?±?36 vs. 195?±?36 nmol/l, p?≤?0.08). Prepregnancy BMI and BMI at the time of GDM screening were both correlated with SHBG concentrations (r?=??0.49 and r?=??0.53, respectively; p ≤?0.001). In multivariate regression analyses, only prepregnancy BMI or BMI at the time of GDM screening remained significant predictors of GDM risk [odds ratio (OR):1.23, 95% confidence interval (CI):1.06–1.47, p ≤?0.01 and OR:1.18, 95% CI:1.02–1.39, p ≤?0.02] while SHBG level did not. On the other hand, 10.7% of the variance in birthweight was explained by SHBG concentrations (p ≤?0.01) independent of the presence of GDM, parity, maternal age, maternal prepregnancy BMI, maternal height, and offspring sex. In conclusion, although SHBG concentration is not an independent predictor of GDM risk when obesity is considered, it is a significant predictor of infant birthweight independent of GDM and prepregnancy BMI.     

Fetal exposure to tobacco: nicotine and cotinine concentration in amniotic fluid and maternal saliva

Objective: Fetal exposure to tobacco constituents is a risk factor for negative birth outcomes. We aimed to determine the relationships between nicotine and cotinine concentrations in amniotic fluid and maternal saliva.

Methods: As part of a therapeutic trial, 42 pregnant smokers agreed to sample amniotic fluid (8 samples from amniocentesis, 34 at birth). Their smoking characteristics were collected along with the newborns’ birth outcomes.

Results: The median concentrations [IQR] in amniotic fluid and saliva were 11 [7–31] and 38 [7–174] μg/L for nicotine and 72 [22–123] μg/L and 55 [17–109] μg/L for cotinine, respectively. Multivariate models showed that saliva cotinine concentration predicted amniotic fluid nicotine and cotinine concentrations (R^2?=^?0.398, p?R^2?=^?0.708, p?R^2?=^?0.237, p?=?0.002).

Conclusions: Maternal saliva sampling for the determination of cotinine concentration is of interest to monitor fetal exposure to nicotine of any origin. Nevertheless, the time elapsed since the last cigarette was a better predictor of birth weight than the biomarkers’ concentrations in amniotic fluid or maternal saliva.     

Mid-trimester maternal heart rate is related to neonatal birth weight

Abstract

Objective(s): We sought to establish the relationship between maternal mid-trimester heart rate (HR) and neonatal birth weight in women at high a priori risk of preeclampsia.

Study Design: Ninety-nine women were recruited following second trimester uterine artery Doppler assessment. Maternal blood pressure (BP) and HR were measured between 23⁺⁴ and 30⁺⁵ weeks gestation and neonatal birth weight was expressed as a z-score. The relationship between the parameters was investigated using Pearson’s correlation coefficient.

Results: There was a significant positive correlation between maternal HR and neonatal birth weight z-score, r?=?0.22 (95% CI: 0.02–0.40), p?=?0.03. An inverse correlation was found between uterine artery Doppler pulsatility index (PI) and maternal HR, r?=??0.43 (95% CI: 0.01–0.40), p?=?0.0001, and neonatal birth weight, r?=??0.3 (95% CI: ?0.47 to ?0.10), p?=?0.004. For neonatal birth weight z-score <?1.65, r?=?0.69 (95% CI: 0.15–0.91), p?=?0.02. There was no relationship between BP and uterine artery Doppler or neonatal birth weight.

Conclusion: The finding of a continuous relationship between maternal HR and neonatal birth weight prior to the onset of fetal growth restriction is novel, suggesting that maternal cardiovascular adaptation is reflected by neonatal birth weight. Lower maternal HR is associated with lower neonatal birth weight and vice versa. Further, we confirm the reported associations between uterine artery Doppler PI and both maternal HR and neonatal birth weight.     

Maternal anthropometrics are associated with fetal size in different periods of pregnancy and at birth. The Generation R Study

Objective  We aimed to examine the associations of maternal anthropometrics with fetal weight measured in different periods of pregnancy and with birth outcomes.
Design  Population-based birth cohort study.
Setting  Data of pregnant women and their children in Rotterdam, the Netherlands.
Population  In 8541 mothers, height, prepregnancy body mass index (BMI) and gestational weight gain were available.
Methods  Fetal growth was measured by ultrasound in mid- and late pregnancy. Regression analyses were used to assess the impact of maternal anthropometrics on fetal weight and birth outcomes.
Main outcome measures  Fetal weight and birth outcomes: weight (grams) and the risks of small (<5th percentile) and large (>95th percentile) size for gestational age at birth.
Results  Maternal BMI in pregnancy was positively associated with estimated fetal weight during pregnancy. The effect estimates increased with advancing gestational age. All maternal anthropometrics were positively associated with fetal size ( P -values for trend <0.01). Mothers with both their prepregnancy BMI and gestational weight gain quartile in the lowest and highest quartiles showed the highest risks of having a small and large size for gestational age child at birth, respectively. The effect of prepregnancy BMI was strongly modified by gestational weight gain.
Conclusions  Fetal growth is positively affected by maternal BMI during pregnancy. Maternal height, prepregnancy BMI and gestational weight gain are all associated with increased risks of small and large size for gestational age at birth in the offspring, with an increased effect when combined.     

Neonatal outcome in polycystic ovarian syndrome patients treated with metformin during pregnancy

Objective.?The present study aimed to evaluate the effect of metformin exposure during pregnancy on neonates of polycystic ovarian syndrome (PCOS) patients.

Method.?Neonatal outcomes of 33 women with PCOS treated with metformin during pregnancy were compared to neonatal outcomes of 66 normal healthy women in a retrospective case–control study.

Results.?The mean birth weight percentile of neonates exposed to metformin in utero during the first trimester was significantly lower than that of neonates delivered to normal healthy matched controls. After controlling for pregnancy complications, this observation became only marginally statistically significant.

Conclusion.?Although metformin is an attractive option for induction of ovulation in PCOS patients, there is a need for more evidence related to its safety during pregnancy.     

The clinical outcomes of unplanned pregnancy in severely obese women

Objective: The objective of this study was to compare the clinical outcomes of unplanned pregnancies among severely obese women with those of planned pregnancies.

Methods: This prospective cohort study included severely obese women (Body Mass Index [BMI] ≥40.0?kg/m²) who delivered a baby weighing ≥500?g over 5 years 2009–2013 in a large university hospital. Maternal weight and height were measured and BMI was calculated at the first prenatal visit.

Results: Of the 650 women, the mean BMI was 43.8?kg/m², mean age was 31.6 years, and 30.0% (n?=?195) were nulliparous. Prenatal complications including gestational diabetes mellitus (GDM), hypertensive and thromboembolic disorders occurred in 56.6% (n?=?368). Compared with planned pregnancies (58.2%, n?=?378), those that were unplanned (41.8%, n?=?272) were associated with increased prepregnancy risk factors including essential hypertension (4.0% versus 1.6%, p?=?0.03) and depression (6.6% versus 3.2%, p?=?0.03). Unplanned pregnancy was associated with a higher macrosomia rate (birthweight?>?4.5?kg) compared with planned pregnancies (p?=?0.03). This was not explained by a higher GDM rate in unplanned pregnancies. Compared with planned pregnancies, unplanned pregnancies were not associated with increased adverse fetomaternal outcomes.

Conclusion: Despite increased prepregnancy risk factors, in severely obese women, unplanned pregnancies were not associated with increased prenatal complications or adverse pregnancy outcomes compared with planned pregnancies.     

Do tall women beget larger babies?

Objective: To evaluate the possible relationship between maternal height and fetal size.

Patients and methods: We used a population-based cohort of apparently healthy mothers of singletons to evaluate quartiles of the maternal height distribution for parity, being overweight or obese, and for gestational age and birth weight parameters. We also generated birth weight by gestational age curves for each quartile.

Results: We analyzed data of 198?745 mothers. Mother from the four quartiles had similar parity, pre-gravid BMI, and gestational age at birth. Short mothers had a significantly higher rate of VLBW and LBW and 2501–4000?g infants, for an OR?=?1.38 (95% CI: 1.17–1.62), OR?=?2.2 (95% CI: 2.05–2.37) and OR?=?1.82 (95% CI: 1.73–1.87) between the shortest and tallest mothers, respectively. By contrast, the opposite trend was noticed for birth weights >4000?g, for an OR?=?2.77 (95% CI: 2.65–2.89) between the tallest and shortest mothers. A very similar “growth curve” was apparent until 33?weeks, when a slower growth velocity was observed for shorter compared with taller women.

Conclusions: Maternal stature does not appear to be associated with gestational age but significantly influences birth weight. Height-related differences between mothers appears to begin after 33 weeks’ gestation.     

Poorer maternal diet quality and increased birth weight*

Objective: Maternal diet and gestational weight gain (GWG) influence birth weight and infant adiposity, which are important predictors of lifetime health. To better understand these relationships, we studied associations between maternal diet and GWG, adiposity, and birth weight in a well characterized cohort of pregnant women.

Study design: Data were obtained from 41 term (>37?weeks), uncomplicated, singleton pregnancies according to pre-pregnancy BMI categories of normal (n?=?11), overweight (n?=?15), or obese (n?=?15). Daily consumption of protein, fat, and carbohydrates and a Healthy Eating Index (HEI-2010) score were determined from 24?h food recall collections. Associations were modeled using multinomial logistic and linear regression.

Results: Neither the third trimester maternal diet quality nor the macronutrient consumption was associated with GWG after adjusting for pre-pregnancy BMI, maternal age, and parity. A ten-point lower HEI-2010 score was associated with 200?g higher infant birth weight and a 1.0?cm longer length. However, maternal HEI-2010 and macronutrient composition were unrelated to infant percent body fat, ponderal index, or abdominal circumference.

Conclusions: Poorer third trimester maternal diet quality was associated with higher birth weight and longer length, but was unrelated to markers of infant adiposity. GWG was independent of third trimester maternal diet composition and quality.     

The association between birth weight at term and long-term endocrine morbidity of the offspring*

Objective: To investigate whether small-for-gestational-age (SGA) and large-for-gestational-age (LGA) birth weight at-term poses an increased risk for long-term pediatric endocrine morbidity.

Study design: A retrospective population-based cohort study compared the incidence of long-term pediatric hospitalizations due to endocrine morbidity of singleton children born SGA, appropriate-for-gestational-age (AGA), and LGA at-term. A multivariate generalized estimating equation (GEE) logistic regression model analysis was used to control for confounders.

Results: During the study period, 235,614 deliveries met the inclusion criteria; of which 4.7% were SGA (n?=?11,062), 91% were AGA (n?=?214,249), and 4.3% were LGA neonates (n?=?10,303). During the follow-up period, children born SGA or LGA at-term had a significantly higher rate of long-term endocrine morbidity. Using a multivariable GEE logistic regression model, controlling for confounders, being delivered SGA or LGA at-term was found to be an independent risk factor for long-term pediatric endocrine morbidity (Adjusted OR?=?1.4; 95%CI?=?1.1–1.8; p?=?.015 and aOR?=?1.4; 95%CI?=?1.1–1.8; p?=?.005, respectively). Specifically, LGA was found an independent risk factor for overweight and obesity (aOR?=?1.7; 95%CI?=?1.2–2.5; p?=?.001), while SGA was found an independent risk factor for childhood hypothyroidism (aOR?=?3.2; 95%CI?=?1.8–5.8; p?=?.001).

Conclusions: Birth weight either SGA or LGA at-term is an independent risk factor for long-term pediatric endocrine morbidity.