A study presented at this year’s European Congress on Obesity (held online, May 10-13) supports recommendations to prevent pregnancy for 12 months after bariatric surgery (obesity) due to an association with results adverse events in pregnancy, including an elevated risk of preterm birth. The study is by Dra. Laura Heusschen, of the Vitalys Obesity Clinic, Rijnstate Hospital, Arnhem, The Netherlands, and colleagues.
More than half of all female patients undergoing bariatric surgery are of reproductive age and the resulting weight loss improves fertility, as well as reducing the risk of gestational diabetes and hypertensive disorders during pregnancy. It also reduces the chance that the baby will be overweight at birth, which is associated with an increased risk of complications for both mother and child.
Current recommendations for women undergoing bariatric surgery are that they should avoid pregnancy 12 to 24 months after the operation to avoid problems caused by ongoing active weight loss and an increased risk of malnutrition. due to a marked reduction in calorie intake. This is more likely to occur during the first 12 months after surgery and may decrease the nutritional supply of the growing fetus; which can affect their development and cause a reduced birth weight and a higher probability of premature birth.
The authors note, however, that “previous studies found no association between time from surgery to conception and adverse pregnancy or neonatal outcomes. In fact, most studies confirm that the risk of ‘these results do not increase during the first 12 months after bariatric surgery compared to subsequent pregnancies.’
The aim of this retrospective multicenter cohort study was to evaluate pregnancy and birth outcomes by surgical intervals until conception and by adherence to the National Academy of Medicine’s recommendations on gestational weight gain. . Births were classified according to the interval of surgery up to conception and gestational weight gain, with the primary outcome variables gestational age at birth, preterm birth, birth weight, and weight percentile by age.
Premature birth was defined as a gestation period of less than 37 weeks, while periods of gestation of less than 32 weeks were classified as very premature according to the definition used by the World Health Organization. The relationship between the weight of a baby at birth in relation to its gestational age was compared with the weight charts at birth, adjusted for sex. Those within the upper 10% were classified as large for their gestational age (LGA), and those below the 10% were classified as small for their gestational age (SGA).
The authors performed a retrospective analysis of 196 individual pregnancies in mothers who had previously undergone bariatric surgery using Roux-en-Y gastric bypass methods, sleeve gastrectomy, or gastric byast from an anastomosis. These pregnancies were assigned to one of three groups according to the time interval from surgery to conception: early group (<12 mesos), grup mitjà (12-24 mesos) i grup tardà (> 24 months). Pregnancy weight gain was classified as inappropriate, adequate, or excessive according to the recommendations of the National Academy of Medicine.
Despite current recommendations, 23.5% of women in this study cohort had conceived within twelve months of their intervention. These “early” pregnancies were associated with a lower gestational age at delivery (267.1 days vs 272.7 and vs 273.1 days), a lower gestational weight gain (-0.9 kg vs +10.2 kg). and +10.0 kg) and a lower neonatal weight (2979 grams) vs. 3161 grams and 3211 grams) than those in the “medium” and “late” groups, respectively.
The authors note: “While the 200 g difference in neonatal weight at birth is probably not clinically relevant, the younger gestational age in the“ early ”group can be alarming, as we have also found a trend toward childbirth more premature in this group “.
The team also found an association between an “inappropriate” gestational weight gain (40.6% in this category) and a lower gestational age at delivery (266.5 days versus 273.8 days) and a lower neonatal weight. (3061 grams versus 3217 grams) compared to pregnancies in the “appropriate” weight gain group. Inadequate gestational weight gain was also associated with a higher rate of preterm birth (15.9% vs. 6.0%) than pregnancies with adequate gestational weight gain.
The authors conclude: “Our results support the recommendation to avoid pregnancy for 12 months after bariatric surgery … We should encourage women who wish to conceive after bariatric surgery to avoid pregnancy until the its weight has stabilized to minimize the risk of inappropriate gestational weight gain In order to break the vicious cycle of obesity and its health consequences, it is important that future research and clinical care focus on preventing babies from being born small for gestational age after bariatric surgery. “