Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be

The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
established the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be (nuMoM2b) to
study women for whom the current pregnancy will lead to their first delivery (nulliparas).
About 40% of pregnant women in the United States are nulliparas. Because little or no
information from previous pregnancy outcomes is available to guide assignment of risk or
mitigating interventions, adverse pregnancy outcomes in nulliparas are especially
unpredictable. The underlying mechanisms of adverse pregnancy outcomes such as preterm
birth, preeclampsia, fetal growth restriction and stillbirth are interrelated and therefore
will be evaluated as part of this study. The information gained will benefit women who are
pregnant or who are considering pregnancy and their physicians. In addition, the knowledge
will support future research aimed at improving care and health outcomes for a critical
group of at-risk women who are currently understudied.

The study is a prospective cohort study of a racially/ethnically/geographically diverse
population of 10,038 nulliparous women with singleton gestations. The women undergo
intensive research assessments during the course of their pregnancies to study the
mechanisms for and prediction of adverse pregnancy outcomes (APOs) in women in their first
pregnancy. The APOs of primary interest are preterm birth, preeclampsia and fetal growth
restriction.

The goals of the study are to 1) determine maternal characteristics, including genetics,
epigenetics, and physiological response to pregnancy as well as environmental factors that
influence and/or predict adverse pregnancy outcome; 2) identify specific aspects of
placental development and function that lead to adverse pregnancy outcome; and 3)
characterize genetic, growth, and developmental parameters of the fetus that are associated
with adverse pregnancy outcome.

Eight academic medical centers or sites had primary responsibility for enrollment and
follow-up of study participants. Several of these sites collected data through additional
academic research centers or nearby hospitals (subsites). A Data Coordinating and Analysis
Center (DCAC) provided input to the protocol, manages the data, and analyzes the data.
Investigators from these institutions have established a partnership with NICHD staff to
develop and implement the study protocol and ancillary studies that acquire and analyze data
to identify biomarkers and understand the mechanism and prediction of preterm birth and
other adverse pregnancy outcomes.

Nulliparous women with an in utero singleton gestation between 6 weeks 0 days and 13 weeks 6
days of pregnancy were recruited through the eight clinical sites and their subsites.
Mechanisms were created in the various prenatal clinics associated with the sites to
identify eligible nulliparous women with singleton pregnancies. Once enrolled, a participant
was followed for the duration of her pregnancy by research staff at the clinical site. Study
visits were scheduled at four times during the pregnancy: 6 weeks 0 days through 13 weeks 6
days estimated gestational age (EGA), 16 weeks 0 days through 21 weeks 6 days EGA, 22 weeks
0 days through 29 weeks 6 days EGA, and at the time of delivery. Data were collected through
personal interview, self-administered questionnaires, clinical measurement, chart
abstraction, and collection of biological specimens (blood, urine, cervico-vaginal fluid).
Additional data (i.e., sleep breathing assessments, actigraphy, fetal adrenal gland
measurements) were collected through ancillary research studies on subsets of the enrolled
women. The set-ups for screening, enrollment and follow-up of participants varied by
clinical site and subsite. However, in each setting, the clinical site staffs included study
investigators, research nurses, research assistants and sonographers. Clinical site staffs
were trained to interview participants, collect and process samples, conduct various
research tests, and input data. Data are managed at the DCAC. Specimens are stored at the
NICHD specimen repository for later analysis.

Inclusion Criteria:

- Nullipara - Pregnant women with no prior pregnancy lasting 20 weeks 0 days or
greater.

- Viable singleton gestation - a single living fetus with fetal cardiac activity at the
most recent ultrasound before enrollment

- Between 6 weeks 0 days and 13 weeks 6 days project estimated gestational age (EGA) at
first study visit.

- Intend to deliver at a participating hospital.

Exclusion Criteria:

- Participant age <13 years.

- History of 3 or more spontaneous abortions.

- Fetal malformation evident at or before enrollment that is likely lethal (e.g.,
anencephaly, hydrops, diffuse subcutaneous edema or cystic hygroma, ectopic cordis,
encephalocele).

- Known fetal aneuploidy (based on chorionic villus sampling).

- Surrogate pregnancy (donor oocyte pregnancy).

- Multifetal reduction.

- Participating in an intervention study that is anticipated to influence maternal or
fetal morbidities/mortality unless it is determined before enrollment that the study
code will be made available.

- Woman previously enrolled in this study, including those consented but delivered
before 20 weeks 0 days gestation.

- Planned pregnancy termination.

- Unable to provide informed consent.