Marie Blomberg

Maternal obesity and morbid obesity: The risk for birth defects in the offspring

BACKGROUND The objective of this study was to assess, in a large data set from Swedish Medical Health Registries, whether maternal obesity and maternal morbid obesity were associated with an increased risk for various structural birth defects. METHODS The study population consisted of 1,049,582 infants born in Sweden from January 1, 1995, through December 31, 2007, with known maternal weight and height data. Women were grouped in six categories of body mass index (BMI) according to World Health Organization classification. Infants with congenital birth defects were identified from three sources: the Swedish Medical Birth Registry, the Register of Birth Defects, and the National Patient Register. Maternal age, parity, smoking, and year of birth were thought to be potential confounders and were included as covariates in the adjusted odds ratio analyses. RESULTS Ten percent of the study population was obese. Morbid obesity (BMI > or = 40) occurred in 0.7%. The prevalence of congenital malformations was 4.7%, and the prevalence of relatively severe malformations was 3.2%. Maternal prepregnancy morbid obesity was associated with neural tube defects OR 4.08 (95% CI 1.87-7.75), cardiac defects OR 1.49 (95% CI 1.24-1.80), and orofacial clefts OR 1.90 (95% CI 1.27-2.86). Maternal obesity (BMI > or = 30) significantly increased the risk of hydrocephaly, anal atresia, hypospadias, cystic kidney, pes equinovarus, omphalocele, and diaphragmatic hernia. CONCLUSION The risk for a morbidly obese pregnant woman to have an infant with a congenital birth defect is small, but for society the association is important in the light of the ongoing obesity epidemic.

Maternal and Neonatal Outcomes Among Obese Women With Weight Gain Below the New Institute of Medicine Recommendations

OBJECTIVE: To estimate whether weight loss or low gestational weight gain in class I–III obese women is associated with adverse maternal and neonatal outcomes compared with gestational weight gain within the new Institute of Medicine recommendations. METHODS: This was a population-based cohort study, which included 32,991 obesity class I, 10,068 obesity class II, and 3,536 obesity class III women who were divided into four gestational weight gain categories. Women with low (0–4.9 kg) or no gestational weight gain were compared with women gaining the recommended 5–9 kg concerning obstetric and neonatal outcome after suitable adjustments. RESULTS: Women in obesity class III who lost weight during pregnancy had a decreased risk of cesarean delivery (24.4%; odds ratio [OR] 0.77, 95% confidence interval [CI] 0.60–0.99), large-for-gestational-age births (11.2%, OR 0.64, 95% CI 0.46–0.90), and no significantly increased risk for pre-eclampsia, excessive bleeding during delivery, instrumental delivery, low Apgar score, or fetal distress compared with obese (class III) women gaining within the Institute of Medicine recommendations. There was an increased risk for small for gestational age, 3.7% (OR 2.34, 95% CI 1.15–4.76) among women in obesity class III losing weight, but there was no significantly increased risk of small for gestational age in the same group with low weight gain. CONCLUSION: Obese women (class II and III) who lose weight during pregnancy seem to have a decreased or unaffected risk for cesarean delivery, large for gestational age, pre-eclampsia, excessive postpartum bleeding, instrumental delivery, low Apgar score, and fetal distress. The twofold increased risk of small for gestational age in obesity class III and weight loss (3.7%) is slightly above the overall prevalence of small-for-gestational-age births in Sweden (3.6%). LEVEL OF EVIDENCE: II

Maternal Obesity and Risk of Postpartum Hemorrhage

OBJECTIVE: To estimate whether maternal obesity was associated with an increased risk for postpartum hemorrhage more than 1,000 mL and whether there was an association between maternal obesity and causes of postpartum hemorrhage and mode of delivery. METHODS: A population-based cohort study including 1,114,071 women with singleton pregnancies who gave birth in Sweden from January 1, 1997 through December 31, 2008, who were divided into six body mass index (BMI) classes. Obese women (class I–III) were compared with normal-weight women concerning the risk for postpartum hemorrhage after suitable adjustments. The use of heparin-like drugs over the BMI strata was analyzed in a subgroup. RESULTS: There was an increased prevalence of postpartum hemorrhage over the study period associated primarily with changes in maternal characteristics. The risk of atonic uterine hemorrhage increased rapidly with increasing BMI. There was a twofold increased risk in obesity class III (1.8%). No association was found between postpartum hemorrhage with retained placenta and maternal obesity. There was an increased risk for postpartum hemorrhage for women with a BMI of 40 or higher (5.2%) after normal delivery (odds ratio [OR] 1.23, 95% confidence interval [CI] 1.04–1.45]) compared with normal-weight women (4.4%) and even more pronounced (13.6%) after instrumental delivery (OR 1.69, 95% CI 1.22–2.34) compared with normal-weight women (8.8%). Maternal obesity was a risk factor for the use of heparin-like drugs (OR 2.86, 95% CI 2.22–3.68). CONCLUSION: The increased risk for atonic postpartum hemorrhage in the obese group has important clinical implications, such as considering administration of prophylactic postpartum uterotonic drugs to this group. LEVEL OF EVIDENCE: II

Maternal body mass index and duration of labor

OBJECTIVE To evaluate whether the duration of the active phase of labor is associated with maternal body mass index (BMI), in nulliparous women with spontaneous onset of labor. STUDY DESIGN Historical prospective cohort study including 63,829 nulliparous women with a singleton pregnancy and a spontaneous onset of labor, who delivered between January 1, 1995 and December 31, 2009. Data were collected from the Perinatal Revision South registry, a regional perinatal database in Southern Sweden. Women were categorized into six classes of BMI. Overweight and obese women were compared to normal weight women regarding duration of active labor. Adjustments were made for year of delivery, maternal age and infant birth weight. RESULTS The median duration of labor was significantly longer in obese women (class I obesity (BMI 30-34.9) = 9.1h, class II obesity (BMI 35-39.9) = 9.2h and class III obesity (BMI > 40) = 9.8h) compared to normal-weight women (BMI 18.5-24.9) = 8.8h (p < 0.001). The risk of labor lasting more than 12h increased with increasing maternal BMI: OR 1.04 (1.01-1.06) (OR per 5-units BMI-increase).The risk of labor lasting more than 12h or emergency cesarean section within 12h, compared to vaginal deliveries within 12h, increased with increasing maternal BMI. Duration of the second stage of labor was significantly shorter in obese women: in class III obesity the median value was 0.45 h compared to normal weight women, 0.55 h (p < 0.001). CONCLUSION In nulliparous women with a spontaneous onset of labor, duration of the active phase of labor increased significantly with increasing maternal BMI. Once obese women reach the second stage they deliver more quickly than normal weight women, which implies that the risk of prolonged labor is restricted to the first stage of labor. It is clinically important to consider the prolonged first stage of labor in obese women, for example when diagnosing first stage labor arrest, in order to optimize management of this rapidly growing at-risk group of women. Thus, it might be reasonable to adapt the considered upper limit for duration of labor, according to maternal BMI.

Impact of maternal age on obstetric and neonatal outcome with emphasis on primiparous adolescents and older women: a Swedish Medical Birth Register Study

Objectives To evaluate the associations between maternal age and obstetric and neonatal outcomes in primiparous women with emphasis on teenagers and older women. Design A population-based cohort study. Setting The Swedish Medical Birth Register. Participants Primiparous women with singleton births from 1992 through 2010 (N=798 674) were divided into seven age groups: <17 years, 17–19 years and an additional five 5-year classes. The reference group consisted of the women aged 25–29 years. Primary outcome Obstetric and neonatal outcome. Results The teenager groups had significantly more vaginal births (adjusted OR (aOR) 2.04 (1.79 to 2.32) and 1.95 (1.88 to 2.02) for age <17 years and 17–19 years, respectively); fewer caesarean sections (aOR 0.57 (0.48 to 0.67) and 0.55 (0.53 to 0.58)), and instrumental vaginal births (aOR 0.43 (0.36 to 0.52) and 0.50 (0.48 to 0.53)) compared with the reference group. The opposite was found among older women reaching a fourfold increased OR for caesarean section. The teenagers showed no increased risk of adverse neonatal outcome but presented an increased risk of prematurity <32 weeks (aOR 1.66 (1.10 to 2.51) and 1.20 (1.04 to 1.38)). Women with advancing age (≥30 years) revealed significantly increased risk of prematurity, perineal lacerations, preeclampsia, abruption, placenta previa, postpartum haemorrhage and unfavourable neonatal outcomes compared with the reference group. Conclusions For clinicians counselling young women it is of importance to highlight the obstetrically positive consequences that fewer maternal complications and favourable neonatal outcomes are expected. The results imply that there is a need for individualising antenatal surveillance programmes and obstetric care based on age grouping in order to attempt to improve the outcomes in the age groups with less favourable obstetric and neonatal outcomes. Such changes in surveillance programmes and obstetric interventions need to be evaluated in further studies.

Bariatric surgery in a national cohort of women: sociodemographics and obstetric outcomes

OBJECTIVE In a large, prospective Swedish national cohort, we investigated individual birth characteristics for women who had undergone bariatric surgery and their obstetric outcome and made comparisons with all other women during the same period. STUDY DESIGN The cohort consisted of 494,692 women born 1973-1983 of which 681 women who had undergone bariatric surgery constituted the index group. RESULTS The index women more often have parents with lower sociodemographic status and are more often born large for gestational age. The women surgically treated before their first child had a shorter gestational length, their children had lower birthweight, and were more often born small for gestational age compared with the children born to the reference mothers. Women whose child was born before their bariatric surgery more often had a cesarean section, and their children were more often large for gestational age. CONCLUSION Preconception bariatric surgery in obese women may be associated with improved obstetric outcomes.

Comparison of first and second trimester ultrasound screening for fetal anomalies in the southeast region of Sweden

Objective. To assess and compare the sensitivity for detecting fetal anomalies and chromosomal aberrations by routine ultrasound examination performed in the second trimester with results from an examination performed at 11–14 weeks gestation. Design. Observational study. Setting. Five centers in the southeast region of Sweden. Population. A total of 21,189 unselected pregnant women. Methods. The scan was performed at one center in the first trimester and at the remaining four centers in the second trimester. Outcome measures resulting from first trimester scanning were compared with those from the second trimester scanning. Main outcome measures. Detection rates of fetal structural anomalies and chromosomal aberrations. Results. At the first trimester scan 13% of all anomalies were detected, and at the second trimester scan 29% were detected. Lethal anomalies were detected at a high level at both times: 88% in the first, 92% in the second. The percentage of chromosomal aberrations discovered at the early scan was 71%, in the later 42%. The percentage of heart malformations detected was surprisingly low. Conclusion. The results showed the advantages of the later scan in discovering anomalies of the heart, urinary tract and CNS, and of the early scan in discovering chromosomal aberrations. Lethal malformations were detected at a high level in both groups, but detection of heart malformations needs improvement.

Weight after childbirth : A 2-year follow-up of obese women in a weight-gain restriction program

Objective. To investigate the effects of a weight‐gain restriction program on weight development or weight maintenance 2 years after childbirth. Design. A case‐control intervention study. Setting. Antenatal care clinics in the southeast of Sweden. Sample. One hundred and fifty‐five obese pregnant women who participated in a weight‐gain restriction program with weekly support during pregnancy and every 6 months during the two first years after childbirth. The control group consisted of 193 obese pregnant women. Methods. Follow‐up weight measurements were done at 12 and 24 months after childbirth. Main Outcome Measures. Weight change in kilogram at 12 and 24 months postpartum. Results. A greater percentage of women in the intervention group showed a weight loss 24 months after delivery than did women in the control group at that same time (p= 0.034). Women in the intervention group who gained less than 7 kg during pregnancy had a significantly lower weight than the controls at the 24 months follow‐up (p= 0.018). The mean value of weight change in the intervention group was −2.2 kg compared to +0.4 kg in the control group from early pregnancy to the follow‐up 12 months after childbirth (p= 0.046). Conclusions. An intervention program with weekly motivational support visits during pregnancy and every 6 months after childbirth seems to have an impact on weight gain up to 24 months after childbirth for those women in the intervention group who succeeded in restricting their gestational weight gain to less than 7 kg.

Avoiding the first cesarean section–results of structured organizational and cultural changes

In 2006 the overall rates of instrumental deliveries (10%) and cesarean sections (CS) (20%) were high in our unit. We decided to improve quality of care by offering more women a safe and attractive normal vaginal delivery. The target group was primarily nulliparous women at term with spontaneous onset of labor and cephalic presentation.

Maternal obesity and risk of Down syndrome in the offspring.

The objective of this article is to determine if maternal obesity is associated with an increased risk of Down syndrome in the offspring and whether the risk estimates for trisomy 21 based on combined screening is affected by maternal body mass index (BMI).