Periods & Puberty - When to worry - Dr Megan Ogilvie

30 May 2016

When to Worry?
Normal pubertal development

Breast budding is the first sign of pubertal development for most young girls.  A few (15%) will have some pubic hair development as the first sign of puberty.   Normally periods start about 2 years after breast budding has started.  If breast budding is not present  by 12 years or if periods have not commenced by 15 years then you should discuss this with your doctor and ask for some blood tests. 

What constitutes normal periods in adolescence?

It is common after periods  commence (menarche ) for there to be a “settling in phase” of irregular cycles ( < 21 days or > 35 days between each period).   However,  If cycles are still irregular 2 years after menarche, there may be medical issues casuing irregularity of periods and it is important to check  things out with your doctor.  Your doctor should ask about weight, exercise, presence of excess hair growth and acne and will probably do one or two simple blood tests.

What constitutes normal periods in adult women?

A normal menstrual cycle is anywhere from 28 – 35 days in length.  The first half of the cycle is the follicular phase (when follicles or eggs are growing) and the second half of the mesntrual cycle is the luteal phase.     Report to your doctor if

  1. menstrual cycle length is consistently outside this timing for > 3 months,
  2. if periods stop for > 3 months,
  3. If periods are excessively heavy or painful

Hormonal medication (the combined contraceptive pill, Depo Provera, Jadelle, Mirena IUD, Jaydess)  all affect the menstrual cycle and changes to the periods when taking one of these medications may be normal.  Check with your doctor as to what to expect.   

What about the combined contraceptive pill (OCP)?

The OCP contains both oestrogen and progesterone.  It is the most commonly used medication in women of reproductive age.   The OCP will not cause irregular periods but it will obscure changes to abnormal menstrual cycles as the OCP creates a withdrawal bleed every time the placebo tablets are taken independent of the underlying hormone pattern.   After an OCP is discontinued,  then periods are expected to return within 3 months.  Report to your doctor if periods do not return within 3 months.

What will happen if I ask for help?

The doctor that you ask for help from should ask you about other symptoms – acne, unwanted hair growth, changes in weight, exercise patterns, any nipple discharge, night sweats or hot flushes.  You should then be offered some hormone testing and sometimes an ultrasound scan of the ovaries and uterus.   Further advice will be dependent on hormone results. 


If you do want to be referred to an Endocrinologist, simply talk to your GP and they can undertake any necessary tests and refer you directly.

For General Practitioners: 
What are the appropriate tests?

Adolescents presenting with delayed menarche should have:

  • Hormone tests, physical examination and a pelvic ultrasound scan.  Appropriate hormone tests are FSH, LH, oestradiol, prolactin, TSH and testosterone.
  • A physical examination is important to determine pubertal development staging.  If the adolescent is uncomfortable with this then it is possible for the adolescent to self assess from Tanner stage pictures.  A pelvic ultrasound is important to confirm the presence of a uterus. 

For a woman with secondary amenorrhoea or oligomenorrhoea:

  • Then appropriate tests include an FSH, LH and oestradiol, TSH, prolactin and testosterone.  A pelvic ultrasound may be appropriate to consider endometrial thickness and ovarian morphology. 
Practice Points:
  1. Please test women who have not had period resumption 3 months after stopping a combined contraceptive pill
  2. Progesterone testing is not contributory to determining the aetiology of oligomenorrhoea.
When should these patients be referred?
  • Please refer if no sign of puberty by age 12 years. 
  • Please refer if menarche has not occurred by age 15 years. 
  • Please refer if hormone testing is abnormal. 
  • Please refer if periods have stopped for more than 3 months or are irregular for more than 6 months. 

Dr Megan Ogilvie,  Dr Stella Milsom, and Dr Susannah O'Sullivan are Endocrinologists at Fertility Associates Auckland.