Body Mass Index (BMI) in women booking for antenatal care: Comparison between selfreported and digital measurements

Objective

We set out to compare measurement of Body Mass Index (BMI) with selfreporting in women early in pregnancy.

Study design

We studied 100 women booking for antenatal care in the first trimester with a normal ongoing pregnancy. Selfreported maternal weight and height were recorded and the Body Mass Index was calculated. Afterwards maternal weight and height were digitally measured and actual BMI was calculated.

Results

If selfreporting is used for BMI classification, we found that 22% of women were classified incorrectly when BMI was measured. 12% of the women who were classified as having a normal selfreported BMI were overweight and 5% classified as overweight were obese. Similar findings have been reported outside pregnancy.

Conclusions

These findings have implications for clinical practice, and for research studies exploring the relationship between maternal adiposity and pregnancy complications.     

Twin weight discordance and maternal weight gain in twin pregnancies.

OBJECTIVE: To evaluate the association between twin weight discordance and maternal weight change during the gestational period. METHOD: One hundred forty-seven twin pregnancies (Group A: <25%, Group B: > or =25% birth weight discordance) were analyzed using Student's t-test, chi(2)-test, and two-way ANOVA at three gestational intervals: before 18 weeks, 18 to 28 weeks, and 28 weeks to birth. RESULT: There was no statistically significant difference between the two groups involving maternal age, parity, duration of pregnancy, height, pregravid weight, and conception method. Group A showed a pattern of constantly increasing maternal weight without a significant change in the twin weight discordance throughout gestation. However, Group B showed a fluctuation in maternal BMI with remarkably elevated twin weight discordance at 28 weeks to birth. CONCLUSION: The results suggest that in twin pregnancies constant maternal weight gain throughout gestation is important for maintaining a twin weight discordance of less than 25%.     

The influence of maternal body composition on birth weight

Objective

To identify the maternal body composition parameters that independently influence birth weight.

Study design

A longitudinal prospective observational study in a large university teaching hospital. One hundred and eighty-four non-diabetic caucasian women with a singleton pregnancy were studied. In early pregnancy maternal weight and height were measured digitally in a standardised way and the body mass index (BMI) was calculated. At 28 and 37 weeks’ gestation maternal body composition was assessed using segmental multifrequency bioelectrical impedance analysis. At delivery the baby was weighed and the clinical details were recorded.

Results

Of the women studied, 29.2% were overweight and 34.8% were obese. Birth weight did not correlate with maternal weight or BMI in early pregnancy. Birth weight correlated with gestational weight gain (GWG) before the third trimester (r = 0.163, p = 0.027), but not with GWG in the third trimester. Birth weight correlated with maternal fat-free mass, and not fat mass at 28 and 37 weeks gestation. Birth weight did not correlate with increases in maternal fat and fat-free masses between 28 and 37 weeks.

Conclusions

Contrary to previous reports, we found that early pregnancy maternal BMI in a non-diabetic population does not influence birth weight. Interestingly, it was the GWG before the third trimester and not the GWG in the third trimester that influenced birth weight. Our findings have implications for the design of future intervention studies aimed at optimising gestational weight gain and birth weight.

Condensation

Maternal fat-free mass and gestational weight gain both influence birth weight.     

The Preterm Prediction Study: association between maternal body mass index and spontaneous and indicated preterm birth

OBJECTIVE: The purpose of this study was to evaluate the relationship between prepregnancy maternal body mass index and spontaneous preterm birth and indicated preterm birth. STUDY DESIGN: This was a secondary analysis of the Maternal-Fetal Medicine Units Network, Preterm Prediction study. Patients were classified into categories that were based on their body mass index. Rates of indicated and spontaneous preterm birth were compared. RESULTS: Five hundred ninety-seven (20.5%) of 2910 women were obese. Obese women had fewer spontaneous preterm births at < 37 weeks of gestation (6.2% vs 11.2%; P < .001) and at < 34 weeks of gestation (1.5% vs 3.5%; P = .012). Women with a body mass index of < 19 kg/m2 had 16.6% spontaneous preterm birth, with a body mass index of 19 to 24.9 kg/m 2 had 11.3% spontaneous preterm birth, with a body mass index of 25 to 29.9 kg/m2 had 8.1% spontaneous preterm birth, with a body mass index of 30 to 34.9 kg/m2 had 7.1% spontaneous preterm birth, and with a body mass index of > or = 35 kg/m2 had 5.2% spontaneous preterm birth (P < .0001). Indicated delivery was responsible for an increasing proportion of preterm births with increasing body mass index (P = .001). Obese women had lower rates of cervical length < 25 mm (5% vs 8%; P = .012). Multivariable regression analysis confirmed a lower rate of spontaneous preterm birth in obese gravid women (odds ratio, 0.57; 95% CI, 0.39-0.83; P = .003). CONCLUSION: Obesity before pregnancy is associated with a lower rate of spontaneous preterm birth.     

Associations of preconception Body Mass Index in women with PCOS and BMI and blood pressure of their offspring

Women with polycystic ovary syndrome (PCOS) have unfavorable metabolic profiles. Their offspring may be affected by such risks. The objective of the current study was to disclose associations between preconception health of these women and health of their offspring. 74 women diagnosed with PCOS according to the Rotterdam criteria were screened systematically before conception. Cardiovascular health of their offspring was assessed at 2.5–4 (n?=?42) or at 6–8?years of age (n?=?32). Multivariate linear regression analysis was performed with adjustments for potential confounders. In the primary analyses the association between preconception Body Mass index (BMI) and offspring BMI was evaluated. Secondly associations between preconception blood pressure, androgens, insulin-resistance (HOMA-IR), and LDL-cholesterol in women with PCOS and BMI and blood pressure of offspring were assessed. Results show that preconception BMI of women with PCOS was positively associated with sex- and age-adjusted BMI of their offspring at 6–8?years of age (β?=?0.55 (95% CI: 0.12 to 0.97), p?=?.012). No other significant associations were found. In conclusion, our data suggest that preconception BMI in PCOS is significantly associated with offspring BMI at 6–8?year of age. If this suggestion could be confirmed this may provide an opportunity for improving the future health of these children.     

The risk of caesarean section in obese women analysed by parity

Objective

This study looked at the association between caesarean section (CS) and Body Mass Index (BMI) in primigravidas compared with multigravidas.

Study design

We enrolled women at their convenience, in the first trimester after an ultrasound examination confirmed an ongoing pregnancy. Weight and height were measured digitally and BMI calculated. After delivery, clinical details were again collected from the Hospital's computerised database.

Results

Of the 2000 women enrolled, there were 50.4% (n = 1008) primigravidas and 49.6% (n = 992) multigravidas. Of the 2000 8.5% were delivered by elective CS and 13.4% were delivered by emergency CS giving an overall rate of 21.9%. The overall CS rate was 30.1% in obese women compared with 19.2% in the normal BMI category (p < 0.001). In primigravidas the increase in CS rate in obese women was due to an increase in emergency CS (p < 0.005) and in multigravidas the increase was due to an increase in elective CS (p < 0.01). In obese primigravidas 20.6% had an emergency section for fetal distress. In obese multigravidas 17.2% had a repeat elective CS.

Conclusion

The influence of maternal obesity on the increase in CS rates is different in primigravidas compared with multigravidas.     

胎儿出生体重与孕期体重指数变化的相关性

目的 :探讨胎儿出生体重与孕期母亲体重指数的相关性。方法 :选择 2 0 0 2年 1月至 2 0 0 2年 10月在我院产前检查并分娩且无内科合并症及产科并发症的初产孕妇 190 0例 ,分别测量并计算孕前体重、分娩前体重、孕期体重变化及体重指数变化 ,采用偏相关分析胎儿出生体重与孕期体重指数的相关性。结果 :无论是控制身高、孕前体重还是控制孕期体重变化都发现胎儿出生体重与孕期体重指数的变化均呈正相关。结论 :胎儿出生体重与孕期体重指数的变化有较好的正相关性。     

Body Mass Index,Follicle-Stimulating Hormone and Their Predictive Value in In Vitro Fertilization

Purpose: The objective was to explore whether body mass and day 3 follicle-stimulating hormone have predictive value on odds of pregnancy after in vitro fertilisation. Few studies show that obesity produces a variety of alterations in the reproductive system, and that women with an elevation of day 3 FSH have declining ovarian function.Methods: The data of one-hundred-seventy-one women who underwent a standard regime of controlled ovarian hyperstimulation was analyzed with particular reference to variations in body mass and hormone levels.Results: By raising BMI and FSH (mIU/mL) by one unit, the odds for pregnancy were decreased by the respective factors 0.84 (95% confidence interval 0.73–0.97) and 0.77 (95% confidence interval 0.59–1.00).Conclusions: The results demonstrate that for the purpose of raising the odds of pregnancy BMI should be reduced. A low FSH value may cause the same effect. Nontheless, obesity and hormonal function may be independent risk factors for failure in assisted reproduction.     

Sporadic pregnancy loss and recurrent miscarriage

Progesterone is essential for the maintenance of pregnancy, and progesterone deficiency is associated with miscarriage. The subject of whether progesterone supplementation in early pregnancy can prevent miscarriage has been a long-standing research question and has been investigated and debated in the medical literature for over 70 years. During this time, several different progestogens have been synthesised and tested for the prevention of miscarriage. In this chapter, we describe the prior evidence alongside the latest research using micronized natural progesterone as well as synthetic progestogens, which were used to treat both recurrent and threatened miscarriage. The totality of evidence indicates that women with a past history of miscarriage who present with bleeding in early pregnancy may benefit from the use of vaginal micronized progesterone. The clinical implications of the findings are discussed.     

The influence of increasing BMI in nulliparous women on pregnancy outcome

Objective

The aim of the study was to demonstrate the influence of BMI in pregnancy on rates of adverse pregnancy outcome in overweight nulliparous women.

Study design

The study was a retrospective review of data from the local hospital database held at the Jessop Wing of the Royal Hallamshire Hospital in Sheffield. We reviewed all nulliparous women with recorded BMI at booking between January 2001 and November 2008 who delivered singleton babies. All the women were stratified into five groups (underweight, normal, overweight, obese, and morbidly obese). The different BMI range groups were compared with the group of women with a normal BMI (20-25). SPSS v15 was used for statistical analysis.

Results

The caesarean section rate rose from 18.2% in women of normal BMI to 40.6% in the morbidly obese women (RR 2.2 - CI 1.7-2.8). Morbidly obese women had three times that risk of macrosomia compared with normal BMI women (RR 3.1 - CI 2.1-4.8). The stillbirth rate was associated with increasing obesity with RR 16.7 (CI 4.9-56) for the morbidly obese women.

Conclusions

Increasing degrees of obesity are associated with increases in the incidence of caesarean section, fetal birth weight and adverse pregnancy outcomes. The increased risk shows an increment in a stepwise fashion among the different BMI groups.     

The association between body mass index and preeclampsia: a meta-analysis

Background: Several observational studies have reported a positive association between elevated body mass index (BMI) and preeclampsia, but no meta-analysis has been conducted yet. This meta-analysis was conducted to estimate the overall association between overweight or obesity and preeclampsia.

Methods: Major electronic databases, including PubMed, Web of Science, and Scopus were searched until August 2015. The reference lists of included studies were screened as well. Epidemiological studies addressing the association between BMI and preeclampsia were enrolled. The heterogeneity across studies was explored by Q-test and I² statistic. The possibility of publication bias was assessed using Begg's and Egger's tests. The results were reported using odds ratio (OR) estimate with its 95% confidence intervals (CI) using a random-effects model.

Results: We identified a total of 1298 references and included 23 studies with 1 387 599 participants. Preeclampsia was associated with overweight (OR?=?1.73; 95% CI: 1.59, 1.87; 21 studies; I^2?=^?62.3%) and obesity (OR?=?3.15; 95% CI: 2.96, 3.35; 22 studies; I^2?=^?36.0%). There was no evidence of publication bias.

Conclusions: There is sufficient evidence that excess body mass index is significantly associated with an increased risk of preeclampsia. Therefore, overweight and obesity can be considered as a predictor of preeclampsia.     

Perinatal Outcomes and Satisfaction with Care in Women with High Body Mass Index

Introduction: The majority of studies on pregnant women with high body mass index (BMI) have focused on medical complications and birth outcome, rather than these women's encounters with health care providers. The aims were to identify the proportion of pregnant women with high BMIs (≥30); compare maternal characteristics and pregnancy and birth outcomes; and assess the experiences of prenatal, intrapartum, and postnatal care in women with high (≥30) and lower (<30) BMIs. Methods: Data were collected through questionnaires and antenatal records from 919 women recruited in mid‐pregnancy at 3 hospitals in the north of Sweden, with a follow‐up questionnaire 2 months after birth. Results: The prevalence of obesity was 15.2%. Women with high BMIs were more often aged 35 years or older and less likely to have a university education. They had more negative attitudes regarding being pregnant and reported more childbirth fear compared to women with lower BMIs, but they did not differ in regard to their feelings about the approaching birth or the first weeks with the newborn. They reported more pregnancy complications and had less continuity of caregiver. High BMI was associated with labor induction and emergency cesarean birth. No differences were found in birth complications; birth experience; or satisfaction with prenatal, intrapartum, or postnatal care. Discussion: The findings reveal that women who are obese have more complicated pregnancies and births but are generally satisfied with the care they receive. There are some differences in the way they experience care. Health care providers have a delicate task to provide sufficient information about health risks while still offering respect, encouragement, and support.     

The incidence and impact of increased body mass index on maternal and fetal morbidity in the low-risk primigravid population

Objective. To determine the incidence and impact of increased body mass index (BMI) on maternal and fetal morbidity in the low-risk primigravid population.

Methods. This was a prospective study with retrospective analysis of delivery outcome data. All low-risk primigravida who met the inclusion criteria during the recruitment period were approached. BMI was calculated using the formula weight/height squared. The participants were divided into five categories: ‘underweight’ (BMI <20 kg/m²), ‘normal’ (BMI 20.01–25 kg/m²), ‘overweight’ (BMI 25.01–30 kg/m²), ‘obese’ (BMI 30.01–40 kg/m²), and ‘morbidly obese’ (BMI >40 kg/m²). Maternal outcomes evaluated included gestation at delivery, onset of labor (spontaneous/induced/elective cesarean section), length of labor, use of oxytocin and epidural, mode of delivery, and estimated blood loss. Perinatal outcome measures included infant birth weight (kg) and centile, gestational age, ponderal index, Apgar score <7 at 5 minutes, cord pH <7.1, presence of meconium grade 3 at delivery, degree of resuscitation required, admission to neonatal intensive care unit (NICU), and duration of stay.

Results. One thousand and eleven women participated in the study. Complete outcome data were available for 833 women (82%). A significant difference was identified in gestation at delivery between the subgroups (p < 0.004). A significant positive correlation was identified between cesarean section rates with increasing BMI, even when gestation was controlled for (p = 0.004). Similarly, women in the normal BMI group remained significantly less likely to have an infant requiring NICU admission than obese women (2.2% vs. 8.6%; p = 0.011).

Conclusion. High BMI is associated with longer gestations, higher operative delivery rates, and an increased rate of neonatal intensive care admission.     

Maternal leptin and body composition in the first trimester of pregnancy

Background.?Leptin is produced mainly by adipocytes. Levels are increased in women with obesity and during pregnancy. Increased levels are also associated with pregnancy complications such as, pre-eclampsia and gestational diabetes mellitus.

Objective.?We studied what component of body composition correlated best with maternal leptin in the first trimester of pregnancy and, whether maternal leptin correlated better with visceral fat rather than fat distributed elsewhere.

Subjects and methods.?Women were recruited in the first trimester. Maternal adiposity was measured using body mass index and advanced bioelectrical impedance analysis. Maternal leptin was measured using an enzyme-linked immunosorbent assay technique.

Results.?Of the 100 subjects studied, the mean leptin concentration was 37.7?ng/ml (range: 2.1–132.8). Leptin levels did not correlate with gestational age in the first trimester, maternal age, parity or birth weight. Serum leptin correlated positively with maternal weight and body mass index, and with the different parameters of body composition. On multiple regression analysis, serum leptin correlated with visceral fat but not fat distributed elsewhere.

Conclusions.?Visceral fat is the main determinant of circulating maternal leptin in the first trimester of pregnancy. This raises the possibility that maternal leptin in early pregnancy may be a marker for the development of metabolic syndrome, including diabetes mellitus.     

Obesity and age at menarche

A cohort study of 3,169 girls born in April 1984-April 1987 in Odense and Aalborg, Denmark, was performed to examine whether maternal prepregnancy body mass index (BMI) accounted for daughter's age of menarche (AOM) and, if so, whether it accounted for part or all of the association between daughter's BMI and AOM. Multiple regression analyses adjusted for covariates indicated a weak inverse association between maternal BMI and AOM and a much stronger inverse association between offspring BMI and AOM independent of maternal BMI.     

Body mass index influences plasma concentration of neuropeptide Y in healthy female volunteers: a pilot study

Neuropeptide Y (NPY) was measured in plasma obtained from healthy female volunteers twice in the natural menstrual cycle or the hormonal cycle caused by oral contraceptives about 2 weeks apart. The ratio between the NPY plasma concentration in the second sample and the first sample was influenced negatively by body mass index (BMI). There were no differences in NPY plasma concentrations on comparing the first and second samples. Age and the use or non-use of oral contraceptives did not exert any influence. BMI might be a confounding factor when determining NPY in the plasma of healthy women.