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Completed

NCT Number: NCT04780087

Pregnant Women Doing Resistance Exercise Training

Despite the increase in numbers of women who engage in heavy, free-weight resistance exercise training (e.g. powerlifting, weightlifting, cross fit), the knowledge on how such exercise may affect fertility, pregnancy and birth outcomes is poor. Based on observational and associational studies of pregnant women in labour, recommendations are not to lift more than 11 kg in external load after mid-term, or to lift more than a total of 100 kg during a day. Ignoring such recommendations is associated to increased risk of miscarriage and preeclampsia, and of low birthweight and premature birth, respectively. As such, fit women who continue to exercise during pregnancy, are met with scepticism and warnings, resulting in shame and insecurity. Such attitudes may also result in physical inactivity during pregnancy, being on the contrary of what is recommended for a healthy pregnancy and delivery. Elite athletes may additionally be deprived from an early return to sport if not being able to keep exercise intensity close to pre-pregnancy period. With poor knowledge on how fit, strong women respond to high external loads during pregnancy exercise, recommendations are to follow the general guidelines.

The aim of this observational study, is to explore how regular resistance exercise training may affect fertility, and how high external loads in resistance exercise training during pregnancy in resistance trained women affect; a)their pregnancy and birth outcome, and b)health of the women and their children up to 12 months post-delivery.

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Key information

Conditions

Pregnancy Related

Age range

18 year–45 year

Sex eligibility

Female

Study type

Observational

Primary location

Therese Fostervold Mathisen

Fredrikstad, 1671, Norway

About this study

Pregnant women who are experienced in heavy, free-weight resistance exercise training, and who choose to continue their exercise regimes during pregnancy, are recruited in social media to regularly respond to an online questionnaire on personal health, foetus development, and the newborn child health.

A reference group of pregnant women being regularly physical active (still not lifting free weights of high loads) are concurrently recruited.

All will respond to questionnaire at mid-term, and week 23, 30 and 40 of pregnancy. During maternity leave the women will be asked to respond to questionnaires at 1 month, 3 months, 6 months and 12 months post-delivery.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Being pregnant
  • Group of interest: Being experienced with heavy, free-weight resistance exercise training, and aiming to continue exercise at comparable level during pregnancy
  • Reference group: being regularly physical active before pregnancy (i.e. at least 2 work- outs per week), but not experienced in heavy, free-weight resistance exercise training

Exclusion criteria

  • Any known metabolic condition or contraindication on doing physical activity during pregnancy (i.e. miscarriages, bleedings).

Treatment and study plan

Primary outcomes

  1. Delivery week

    Time frame: At delivery time

    The selfreported pregnancy week for delivery

  2. Delivery method

    Time frame: At delivery time

    Participants report the method for delivery, choosing from natural delivery, delivery with assistance (e.g. birth forceps, vacuum delivery), caesarean section.

  3. Pregnancy complications at week 23

    Time frame: During pregnancy up to week 23

    Number of participants who report any complications during pregnancy, choosing from a list of alternatives (yes/no) (preeclampsia, nausea, fatigue, low back pain, pelvic pain, constipation, mood swings, birth anxiety, gestational depression, anemia, hypertension, pregnancy diabetes, foetus growth retardation)

  4. Pregnancy complications at week 30

    Time frame: Pregnancy week 23 to 30

    Number of participants who report any complications during pregnancy, choosing from a list of alternatives (yes/no) (preeclampsia, nausea, fatigue, low back pain, pelvic pain, constipation, mood swings, birth anxiety, gestational depression, anemia, hypertension, pregnancy diabetes, foetus growth retardation)

  5. Pregnancy complications at week 40

    Time frame: Pregnancy week 30 to 40

    Number of participants who report any complications during pregnancy, choosing from a list of alternatives (yes/no) (preeclampsia, nausea, fatigue, low back pain, pelvic pain, constipation, mood swings, birth anxiety, gestational depression, anemia, hypertension, pregnancy diabetes, foetus growth retardation)

  6. Childs weight at birth

    Time frame: At delivery time

    The weight of the child

  7. Childs length at birth

    Time frame: At delivery time

    The length of the child

  8. Apgar score 5 minutes

    Time frame: At delivery time (5 minutes post-delivery)

    The Apgar score 5 minutes post-delivery. This test checks a baby's heart rate, muscle tone, and other signs to see if extra medical care or emergency care is needed. The test is usually given twice: once at 1 minute after birth, and again at 5 minutes after birth. Scores below 4 indicates need for lifesaving measures, and higher scores indicates better health.

  9. Miscarriage

    Time frame: Previous and up to October 2023

    Number of miscarriages

  10. Urinary incontinence before pregnancy

    Time frame: Any experience before pregnancy

    Number of participants reporting any challenges with urinary incontinence, and if it occurs; if it is only during increased abdominal pressure (coughing, laughing), or heavy lifting (choosing from a list of "always", only during increased abdominal pressure, only during lifting of heavy load)

  11. Urinary incontinence during pregnancy

    Time frame: At pregnancy week 23, 30 and 40

    Number of participants reporting any urinary incontinence, and if it occurs; if it is only during increased abdominal pressure (coughing, laughing), or heavy lifting (choosing from a list of "always", only during increased abdominal pressure, only during lifting of heavy load)

  12. Urinary incontinence after delivery

    Time frame: Post-delivery: 1 month-, 3months-, 6 months- and 12 months

    Number of participants reporting any urinary incontinence, and if it occurs; if it is only during increased abdominal pressure (coughing, laughing), or heavy lifting (choosing from a list of "always", only during increased abdominal pressure, only during lifting of heavy load)

  13. Anal insufficiency before pregnancy

    Time frame: Any experience before pregnancy

    Number of participants reporting any challenges with fecal incontinence

  14. Anal insufficiency during pregnancy

    Time frame: At pregnancy week 23, 30 and 40

    Number of participants reporting any challenges with fecal incontinence

  15. Anal insufficiency after delivery

    Time frame: Post-delivery: 1 month-, 3months-, 6 months- and 12 months

    Number of participants reporting any fecal incontinence and if it has worsened after giving birth

  16. Injuries during pregnancy up to week 23

    Time frame: During pregnancy up to week 23

    Number of participants reporting on any exercise related injuries occuring during pregnancy, choosing from a list of anatomical locations

  17. Injuries during pregnancy, up to week 30

    Time frame: Pregnancy week 23 to 30

    Number of participants reporting on any exercise related injuries occuring during pregnancy, choosing from a list of anatomical locations

  18. Injuries during pregnancy, up to week 40

    Time frame: Pregnancy week 30 to 40

    Number of participants reporting on any exercise related injuries occuring during pregnancy, choosing from a list of anatomical locations (yes/no)

  19. Analgesic during delivery

    Time frame: At delivery time

    Number of participants reporting use of analgesic during delivery, and what type of analgesic (e.g. nitrous oxide, epidural)

Secondary outcomes

  1. Body weight at week 23

    Time frame: Pregnancy week 23

    Participants report on body weight changes during pregnancy

  2. Body weight at week 30

    Time frame: Pregnancy week 30

    Participants report on body weight changes during pregnancy

  3. Body weight at week 40

    Time frame: Pregnancy week 40

    Participants report on body weight changes during pregnancy

  4. Body weight post-delivery, 1month

    Time frame: Postpartum, 1 month after delivery

    Participants report on body weight changes after pregnancy

  5. Body weight post-delivery, 3 months

    Time frame: Postpartum, 3 months after delivery

    Participants report on body weight changes after pregnancy

  6. Body weight post-delivery, 6 months

    Time frame: Postpartum, 6 months after delivery

    Participants report on body weight changes after pregnancy

  7. Body weight post-delivery, 12 months

    Time frame: Postpartum, 12 months after delivery

    Participants report on body weight changes after pregnancy

  8. Changes in external loads used in exercise training

    Time frame: During pregnancy

    Participants report on changes in external loads used in exercise during pregnancy (% of normal loading used pre-pregnancy)

  9. Changes in external loads used in exercise training, up to week 23

    Time frame: During pregnancy, week 23

    Participants report on changes in external loads used in exercise during pregnancy (% of normal loading used pre-pregnancy)

  10. Changes in external loads used in exercise training

    Time frame: Post-delivery: 1 month-, 3months-, 6 months- and 12 months

    Participants report on changes in external loads used in exercise after pregnancy (% of normal loading used pre-pregnancy)

  11. Changes in exercise volume during pregnancy, up to week 23

    Time frame: During pregnancy, week 23

    Participants report on changes in exercise volume (number of sessions per week) during pregnancy

  12. Changes in exercise volume during pregnancy, up to week 30

    Time frame: During pregnancy, week 30

    Participants report on changes in exercise volume (number of sessions per week) during pregnancy

  13. Changes in exercise volume during pregnancy, up to week 40

    Time frame: During pregnancy, week 40

    Participants report on changes in exercise volume (number of sessions per week) during pregnancy

  14. Changes in exercise volume after pregnancy

    Time frame: Post-delivery: 1 month-, 3months-, 6 months- and 12 months

    Participants report on changes in exercise volume (number of sessions per week) after pregnancy

  15. Injuries from exercise during maternity leave

    Time frame: Post-delivery: 1 month-, 3months-, 6 months- and 12 months

    Reporting on any exercise related injuries occuring during maternity leave (up to 12 months post-delivery), choosing from a list of anatomical locations

  16. Fertility

    Time frame: Before pregnancy

    Reports on any fertility problems or use of fertility techniques in order to become pregnant

  17. Bloodpressure

    Time frame: At pregnancy week 23, 30 and 40, and at 1 month-, 3months-, 6 months- and 12 months postdelivery,

    Bloodpressure measures, and numbers above/below clinical cut offs (having hypo-or hypertension)

  18. Symphysis-fundus measure

    Time frame: At pregnancy week 23, 30 and 40

    symphysis fundus measure during pregnancy; as a measure for growth of the fetus, evaluated according to national/international standards

Other outcomes

  1. Use of supplements

    Time frame: At pregnancy week 23, 30 and 40, and at 1 month-, 3months-, 6 months- and 12 months postdelivery,

    Number of participants reporting use of dietary supplements, and what kind of supplements

  2. Use of caffein (coffee, energydrinks, sodawater)

    Time frame: At pregnancy week 23, 30 and 40, and at 1 month-, 3months-, 6 months- and 12 months postdelivery,

    Number of participants reporting use of caffein, and in what doses per day

  3. Intake of alcohol

    Time frame: At pregnancy week 23, 30 and 40, and at 1 month-, 3months-, 6 months- and 12 months postdelivery,

    Number of participants reporting intake of alcohol, and how regularly (choosing between no, daily, weekly, monthly)

  4. Use of tobacco/cigarettes or snus

    Time frame: At pregnancy week 23, 30 and 40, and at 1 month-, 3months-, 6 months- and 12 months postdelivery,

    Number of participants reporting any use

  5. Use of any prescribed drugs

    Time frame: At pregnancy week 23, 30 and 40, and at 1 month-, 3months-, 6 months- and 12 months postdelivery,

    Number of participants reporting any use, and what type of drug

Sponsors and collaborators

Lead sponsor

Ostfold University College

Other

Registry information

Official study title

Experiences by Pregnant Power Athletes, and Health Related Outcomes in Mother and Infants, After Resistance Exercise Training During Pregnancy

Acronym: PREG_RET

Important dates

Study start
2020
Primary completion
2023
Study completion
2023
First posted
Mar 3, 2021
Registry last updated
Apr 2, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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