Early pregnancy weight gain is extremely important in twin and multiple gestation pregnancy. Recommendations for appropriate weight gain are based upon pre-pregnancy weight and BMI. To calculate your BMI simply follow this link from the CDC1. (CDC BMI Link).
Table 2: Gestational Weight Gain Recommendations for Twin Pregnancies
This information is based upon a cohort of studies which demonstrated that women who met or exceeded these minimum weights experienced fewer preterm births and higher birth weights compared with women who did not meet these minimum weights described by these guidelines.
To achieve appropriate gestational weight gain, a normal weight woman needs to increase her dietary intake by 600 calories/day. This is approximately 300 calories/day above that for a singleton pregnancy. After 20 weeks of gestation, weight gain should be approximately 1.75 pounds/week for underweight women and approximately 1.5 pounds/week for normal weight women, with the same or slightly lower weekly weight gain in overweight and obese women.2
So, when should I focus on gaining the most weight for my babies?
As a mom carrying twins it is recommended to gain weight earlier and more aggressively than as a singleton mother. Early weight gain helps to ensure that your babies will have the best possible birth weight no matter when labor occurs (which is especially important due to risk for pre-term or early labor and delivery).
Research has shown that early weight gain for twin pregnancies is crucial although until recently there have been no significant studies to indicate when specifically weight gain is the most important for twin moms. A 2014 study in the Journal of Perinatology has shown that mid-pregnancy weight gain specifically at 20-28 weeks is the most important and appears to have a greater impact on pregnancy outcomes than first trimester weight gain. According to this study, poor mid-pregnancy weight gain is the number one and strongest predictor of PTB (pre-term birth) at <32 weeks gestation.3 According to research involving 489 twin pregnancies delivered between 2001 and 2013, women with inadequate weight gain at 20-28 weeks were 2.8 times more likely to deliver at <32 weeks.3
CDC staff. Adult BMI Calculator. Centers for Disease Control and Prevention. Click here for bmi calculator online
Published May 15, 2015. Accessed May 6, 2016.
Chasen ST, Chervenak FA. Twin Pregnancy: Prenatal issues. In: UpToDate, Post, TW (Ed), UpToDate, Waltham, MA, 2016.
Pettit KE, Lacoursiere DY, Schrimmer DB, et al. The association of inadequate mid-pregnancy weight gain and preterm birth in twin pregnancyies. J Perinatol 2015; 35:85.
About the Author:
Natalie Smith is a twin mom and founder of TwinBabyBargains.com, the first online twin consignment marketplace. She is also currently a practicing physician assistant in emergency medicine as well as a full time faculty member at East Carolina University within the Dept. of Physician Assistant Studies. Her husband Steve is a registered nurse working in pediatric emergency medicine and is also a nurse educator. They live in New Bern, NC with their twin boys Eli and Archer.
Natalie Smith, MS PA-C
Clinical Assistant Professor
East Carolina University
Dept. of Physician Assistant Studies